Irradiation device

Abstract

This invention provides an illumination device that allows for more flexible modification of the light distribution from the light guide, even after the construction of the optical system, including the light guide and observation system, has been completed. [Solution] The irradiation device 1 comprises a light source 10, an adjustment member 30 including at least one optical fiber from a plurality of optical fibers having different aperture angles, and a light guide 40 including only at least one optical fiber having the same aperture angle. The adjustment member 30 is positioned between the light source 10 and the light guide 40 such that the relative position between the adjustment member 30 and the light guide 40 is variable.

Description

Technical Field

[0001] The present disclosure relates to an irradiation device.

Background Art

[0002] In fields such as medical and industrial, an irradiation device used for an endoscope capable of observing a short-distance subject and a long-distance subject is known. Such an irradiation device is required to be able to flexibly control the light distribution. Conventionally, a method of configuring a light guide by a plurality of types of optical fibers having different numerical apertures is known. For example, for each type of subject to be observed, by increasing or decreasing the mixing ratio of an optical fiber with a small numerical aperture through which illumination light propagates and an optical fiber with a large numerical aperture, the light distribution from the light guide in the observation of the subject can be optimized.

[0003] For example, Patent Document 1 discloses an endoscope having a light guide configured by a plurality of types of optical fibers having different numerical apertures. In this endoscope, by adjusting the incident ratio of incident light to different types of optical fibers constituting the light guide with a filter, the mixing ratio of optical fibers having different numerical apertures through which illumination light propagates is adjusted. By adjusting the mixing ratio of the optical fibers through which illumination light propagates, the light distribution according to the angle of the illumination light is adjusted.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the prior art described in Patent Document 1, the optical system, including the light guide, image guide, and camera, is integrated. As a result, after the construction of the optical system is complete, it is not easy to change the type of optical fiber constituting the light guide to have a different combination of aperture angles. In addition, if it is acceptable to construct the light guide with only one type of optical fiber having one aperture angle, the light guide described in Patent Document 1 may have the possibility of mixing in illumination light irradiated at an aperture angle different from the intended one. This may result in the inability to obtain an optimal light distribution.

[0006] This disclosure aims to provide an illumination device that allows for more flexible modification of the light distribution from a light guide, even after the construction of the optical system, including the light guide and observation system, has been completed. [Means for solving the problem]

[0007] To solve the above problems, an irradiation apparatus according to one embodiment of the present disclosure is provided. Light source and An adjustment member including at least one of several types of optical fibers having different aperture angles, A light guide containing only at least one optical fiber with identical aperture angles, Equipped with, The adjustment member is positioned between the light source and the light guide such that the relative position between the adjustment member and the light guide is variable. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide an illumination device that allows for more flexible modification of the light distribution from the light guide, even after the construction of the optical system, including the light guide and observation system, has been completed. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the configuration of the irradiation device according to the first embodiment. [Figure 2]FIG. 1 is a first schematic diagram showing an example of the positional relationship between the exit end of the adjustment member and the entrance end of the light guide. [Figure 3] FIG. 1 is a schematic diagram showing an example of the arrangement relationship between the optical fiber bundle 20 for light guiding and the adjustment member. [Figure 4] FIG. 1 is a schematic diagram showing a method for manufacturing the adjustment member. [Figure 5] FIG. 1 is a second schematic diagram showing an example of the positional relationship between the exit end of the adjustment member and the entrance end of the light guide. [Figure 6] FIG. 1 is a third schematic diagram showing an example of the positional relationship between the exit end of the adjustment member and the entrance end of the light guide. [Figure 7] This is a front image of the exit end of the adjustment member in Example 1. [Figure 8] In Example 1, this is a schematic diagram showing the optical fiber arrangement at the entrance end of the light guide. [Figure 9] FIG. 1 is a schematic diagram showing the positional relationship between the exit end of the adjustment member and the entrance end of the light guide during measurement of the light distribution in Example 1. [Figure 10A] In Example 1, this is a first image showing an example where the entrance end of the light guide is placed in close contact with the exit end of the adjustment member. [Figure 10B] In Example 1, this is a second image showing an example where the entrance end of the light guide is placed in close contact with the exit end of the adjustment member. [Figure 11] FIG. 1 is a schematic diagram showing the measurement system when measuring the light distribution. [Figure 12] This is the measurement result of the light distribution in Example 1. [Figure 13] FIG. 1 is a schematic diagram showing the configuration of the irradiation device 1 in Example 2. [Figure 14A] This is a front image of the observation part in Example 2. [Figure 14B] FIG. X is a schematic diagram of the end face of the observation part in Example 2. [Figure 15] FIG. 1 is a schematic diagram showing the positional relationship between the exit end of the adjustment member and the entrance end of the light guide during observation in Example 2. [Figure 16] This is an example of the observation result in Example 2.

Mode for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present disclosure will be mainly described with reference to the accompanying drawings.

[0011] (First Embodiment) FIG. 1 is a schematic diagram showing the configuration of an irradiation device 1 according to the first embodiment. With reference to FIG. 1, an outline of an example of the configuration and function of the irradiation device 1 according to the first embodiment will be described.

[0012] The irradiation device 1 includes, for example, a light source 10, a light guide fiber bundle 20, an adjustment member 30, and a light guide 40. The irradiation device 1 propagates the emitted light from the light source 10 in the order of the light guide fiber bundle 20, the adjustment member 30, and the light guide 40, and irradiates the observation object. The irradiation device 1 emits illumination light having a predetermined light distribution from the light guide 40. The irradiation device 1 may be configured as a single device, or may be combined with an observation system including an image guide, a camera, etc. used for observing the observation object illuminated by the illumination light to form an endoscope.

[0013] In FIG. 1, as an example, the emitted light from the light source 10 enters the adjustment member 30 after passing through the light guide fiber bundle 20, but the configuration of the irradiation device 1 is not limited to this. The irradiation device 1 may not have the light guide fiber bundle 20. At this time, the emitted light from the light source 10 may directly enter the adjustment member 30.

[0014] In the present disclosure, the “observation object” includes, for example, any object such as organs, tissues, etc. inside the human body to be inspected. Without being limited to this, the “observation object” may include any other object that can be observed by receiving light irradiation by the irradiation device 1. The “light distribution” includes, for example, the distribution of light power for each emission angle with respect to the optical axis of the illumination light emitted from the light guide 40.

[0015] The light source 10 has an arbitrary light-emitting element that generates light that serves as the source of illumination light for illuminating the object to be observed. The light-emitting element may be, for example, an LED (Light Emitting Diode) element or an LD (Laser Diode) element. The light source 10 may have only one light-emitting element or may have multiple light-emitting elements.

[0016] The light guide fiber bundle 20 includes only at least one optical fiber with the same aperture angle. For example, the light guide fiber bundle 20 is configured as a light guide in which multiple optical fibers with the same aperture angle are bundled together. The light guide fiber bundle 20 receives the light emitted from the light source 10 at one end, propagates it within itself, and emits it from the other end toward the adjustment member 30.

[0017] The adjustment member 30 includes at least one optical fiber from among a plurality of optical fibers having different aperture angles. In the first embodiment, for example, the adjustment member 30 includes a plurality of optical fibers having different aperture angles. The adjustment member 30 receives the light emitted from the light guide fiber bundle 20 at one end, propagates it inside, and emits it from the other end toward the light guide 40.

[0018] The light guide 40 includes only at least one optical fiber with the same aperture angle. For example, the light guide 40 is composed of multiple optical fibers bundled together, each with the same aperture angle. The light guide 40 receives the light emitted from the adjustment member 30 at a rectangular array section 41, which is one end of the light guide 40, propagates it within the section, and emits it from the other end towards the object to be observed. The light guide 40 emits illumination light having a predetermined light distribution towards the object to be observed.

[0019] In the irradiation device 1 described above, the adjustment member 30 is positioned between the light source 10 and the light guide 40 such that the relative position between the adjustment member 30 and the light guide 40 is variable. As shown in Figure 1, when the irradiation device 1 has a light guide fiber bundle 20, the adjustment member 30 is positioned between the light guide fiber bundle 20 and the light guide 40 such that the relative position between the adjustment member 30 and the light guide 40 is variable.

[0020] The position of at least one of the adjustment member 30 and the light guide 40 may be variable. For example, the position of the light guide 40 may be fixed, and only the position of the adjustment member 30 may be variable. In this case, the relative position between the adjustment member 30 and the light guide 40 changes as the adjustment member 30 moves relative to the light guide 40. For example, the position of the adjustment member 30 may be fixed, and only the position of the light guide 40 may be variable. In this case, the relative position between the adjustment member 30 and the light guide 40 changes as the light guide 40 moves relative to the adjustment member 30.

[0021] The adjustment member 30 is detachably positioned relative to the light source 10 and the light guide 40. As shown in Figure 1, when the irradiation device 1 has a light guide fiber bundle 20, the adjustment member 30 is detachably positioned between the light guide fiber bundle 20 and the light guide 40, relative to the light guide fiber bundle 20 and the light guide 40. For example, the light source 10 and the light guide fiber bundle 20 together are considered as a light source that emits light to the adjustment member 30.

[0022] Figure 2 is a first schematic diagram showing an example of the positional relationship between the exit end of the adjustment member 30 and the incident end of the light guide 40 in Figure 1. Figure 2 schematically shows a front view of the exit end of the adjustment member 30 when viewed from the light guide 40 side at the connection portion between the adjustment member 30 and the light guide 40 shown in Figure 1. In this disclosure, the "exit end" of the adjustment member 30 means the end face of the adjustment member 30 that is in contact with the light guide 40. The "incident end" of the light guide 40 means the end face of the light guide 40 that is in contact with the adjustment member 30.

[0023] As shown in Figure 2, in the first embodiment, the exit end of the adjustment member 30 includes a first region 31 and a second region 32. The first region 31 and the second region 32 are separated by a boundary line 33 at the exit end of the adjustment member 30 and are adjacent to each other. When the position of the adjustment member 30 is fixed, the incident end of the light guide 40 can move on the exit end of the adjustment member 30. In Figure 2, the direction of movement of the light guide 40 is shown as the left-right direction on the plane of the paper for convenience, but is not limited to this. The direction of movement of the light guide 40 may be the up-down direction or an oblique direction in Figure 2.

[0024] Figure 3 is a schematic diagram showing an example of the arrangement relationship between the light guide fiber bundle 20 and the adjustment member 30 in Figure 1. Referring to Figure 3, the conditions that the distance between the light source and the adjustment member 30, and the size of the light source must satisfy will be explained. As shown in Figure 1, when the irradiation device 1 has a light guide fiber bundle 20, the light source includes the light guide fiber bundle 20 in addition to the light source 10.

[0025] The size b of the light source and the distance a between the adjustment member 30 and the light source are determined so that the light emitted from the light source illuminates the entire effective diameter A of the adjustment member 30. For example, the size b of the light guide fiber bundle 20 included in the light source and the distance a between the adjustment member 30 and the light guide fiber bundle 20 are determined so that the light emitted from the light guide fiber bundle 20 illuminates the entire effective diameter A of the adjustment member 30.

[0026] In this disclosure, “effective diameter A” is the diameter of the portion of the optical fiber constituting the adjustment member 30 in which light is coupled so that the total internal reflection condition is satisfied between the core and cladding. The effective diameter A of the adjustment member 30 corresponds to the bundle diameter of the portion of the adjustment member 30 in which the optical fibers are bundled. “Distance a” is the distance between the exit end face of the optical guide fiber bundle 20 and the incident end face of the adjustment member 30. “Size b” is the diameter of the portion of the optical fiber constituting the optical guide fiber bundle 20 in which light is coupled so that the total internal reflection condition is satisfied between the core and cladding. The size b of the optical guide fiber bundle 20 corresponds to the bundle diameter of the portion of the optical fibers bundled in the optical guide fiber bundle 20.

[0027] The size b and distance a are determined, for example, so that the beam diameter of the light emitted from the light guide fiber bundle 20 is equal to or greater than the effective diameter A at the incident end face of the adjustment member 30. For example, if the aperture angle of the light guide fiber bundle 20 with size b is large, distance a may be relatively small. Conversely, if the aperture angle of the light guide fiber bundle 20 with size b is small and size b is small relative to the effective diameter A, distance a must be relatively large. Even if the aperture angle of the light guide fiber bundle 20 with size b is small, if size b is about the same as the effective diameter A, distance a may be relatively small.

[0028] Figure 4 is a schematic diagram showing the method for manufacturing the adjustment member 30 shown in Figure 1. First, a first optical fiber bundle 34 having a first aperture angle and a second optical fiber bundle 35 having a second aperture angle are prepared. The first and second aperture angles are different from each other. The first optical fiber bundle 34 and the second optical fiber bundle 35 are each cut in half, and the halves are joined together so that the cut surfaces are in contact, thereby manufacturing the adjustment member 30.

[0029] Methods for joining the first optical fiber bundle 34 and the second optical fiber bundle 35 include using an adhesive on the bonding surface or fusing the optical fiber bundles together. In this case, to reduce optical coupling such as crosstalk between the first optical fiber bundle 34 and the second optical fiber bundle 35, the bonding surface may be coated with black ink.

[0030] In a front view of the output end of the adjustment member 30, the first optical fiber included in the first optical fiber bundle 34 is positioned only in the first region 31 at the output end of the adjustment member 30. Similarly, the second optical fiber included in the second optical fiber bundle 35 is positioned only in the second region 32 adjacent to the first region 31 at the output end of the adjustment member 30. The adjustment member 30 includes a first optical fiber and a second optical fiber with different aperture angles.

[0031] In Figure 4, the first optical fiber bundle 34 and the second optical fiber bundle 35 are each cut in half. However, the end faces of the first optical fiber bundle 34 and the second optical fiber bundle 35 may each be sectors with any central angle, as long as the end face of the adjustment member 30 when they are joined together is circular. For example, the central angle of the sector at the end face of the first optical fiber bundle 34 may be 120°, and the central angle of the sector at the end face of the second optical fiber bundle 35 may be 240°. For example, the central angle of the sector at the end face of the first optical fiber bundle 34 may be 210°, and the central angle of the sector at the end face of the second optical fiber bundle 35 may be 150°.

[0032] By appropriately combining the first optical fiber bundle 34 and the second optical fiber bundle 35, it is possible to manufacture an adjustment member 30 having the desired combination of aperture angles. Depending on the adjustment member 30 used, the light distribution of the light emitted from the light guide 40 will differ. Therefore, by appropriately manufacturing the adjustment member 30, illumination light with an appropriate light distribution will be emitted from the light guide 40.

[0033] Figure 5 is a second schematic diagram showing an example of the positional relationship between the exit end of the adjustment member 30 and the incident end of the light guide 40 in Figure 1. At least a portion of the incident end of the light guide 40 overlaps with the exit end of the adjustment member 30. In the example shown in Figure 5, the entire incident end of the light guide 40 overlaps with the exit end of the adjustment member 30. Referring to Figure 5, the relationship between the shape and size of the exit end of the adjustment member 30 and the incident end of the light guide 40 in Figure 1 will be mainly explained.

[0034] The arrangement shape of the optical fibers at the incident end of the light guide 40 is not particularly limited and may be arbitrarily determined by the purpose or the number of boundary lines 33 of the adjustment member 30. For example, the arrangement shape may be contained within the end face shape of the optical fiber bundle with the smallest end face area among the multiple types of optical fiber bundles that constitute the adjustment member 30. In the case of an adjustment member 30 made by combining halved optical fiber bundles, the optical fibers at the incident end of the light guide 40 may be arranged in a rectangular shape. By arranging the optical fibers in a rectangular shape, when the relative position between the adjustment member 30 and the light guide 40 is changed to change the ratio of light emitted from the first region 31 and the second region 32 of the adjustment member 30, respectively, to be received by the incident end of the light guide 40, the change in that ratio can be made smaller with respect to the change in relative position. As a result, more precise light distribution control becomes possible.

[0035] For example, the end face shape of the incident end of the light guide 40 is contained within the shape of the region with the smaller area among the first region 31 and the second region 32. The incident end of the light guide 40, in which the optical fibers are arranged in a rectangular shape, constitutes the rectangular arrangement portion 41. The incident end of the light guide 40 and the incident end of the rectangular arrangement portion 41 have the same end face. Therefore, the end face shape of the rectangular arrangement portion 41 is contained within the shape of the region with the smaller area among the first region 31 and the second region 32 of the adjustment member 30.

[0036] The area of ​​the incident end of the light guide 40 may be smaller than the area of ​​the first region 31 and the second region 32, respectively. For example, if the effective area of ​​the first region 31 is S1, the effective area of ​​the second region 32 is S2, and the area of ​​the incident end of the rectangular arrangement portion 41 is S LLet S1, S2, and S L The relationship between the sizes is S1≧S2≧S L This may also be the case. Here, the area of ​​the incident end of the rectangular array portion 41 means the area occupied by the optical fiber at the end face of the rectangular array portion 41.

[0037] Due to the above-described relationship between the shape and occupied area of ​​the output end of the adjustment member 30 and the input end of the light guide 40, the irradiation device 1 can receive light emitted from the first optical fiber bundle 34, or light emitted from the second optical fiber bundle 35, or a combination thereof, across the entire rectangular array section 41.

[0038] The ratio of the areas of the first region 31 and the second region 32 is not particularly limited. However, as mentioned above, S1≧S2≧S L Due to this relationship, if the ratio of optical fiber bundles constituting the adjustment member 30 is extremely skewed, the area S of the incident end of the rectangular arrangement portion 41 will be affected accordingly. L This reduces the amount of light incident on the light guide 40. This leads to a decrease in the amount of illumination light emitted from the illumination device 1. In practice, the output end of the adjustment member 30 may be equally divided by the first region 31 and the second region 32. This allows the light guide 40 to receive the maximum amount of light emitted from the output end of the adjustment member 30.

[0039] The direction of movement of the rectangular array portion 41 relative to the boundary line 33 formed by multiple types of optical fiber bundles constituting the adjustment member 30, and the mode of movement of the rectangular array portion 41 relative to the output end of the adjustment member 30 are not particularly limited and may be arbitrarily determined depending on the purpose or the number of boundary lines 33. The mode of movement includes, for example, linear movement and curved movement.

[0040] In Figure 5, the line along which the intersection of the diagonals of the incident end of the rectangular array section 41 moves is referred to as the movement line L. The boundary line 33 between the first region 31 and the second region 32 and the movement line L of the light guide 40 are non-parallel to each other. In addition, at least one point on the movement line L, the incident end of the light guide 40 may overlap the first region 31 and the second region 32. For example, the movement line L for the adjustment member 30 intersects the boundary line 33 between the first region 31 and the second region 32 inside the exit end of the adjustment member 30. In the example shown in Figure 5, the boundary line 33 corresponds to the diameter of the circular shape that constitutes the exit end of the adjustment member 30. The movement line L intersects this diameter at the center point of the circle.

[0041] Figure 6 is a third schematic diagram showing an example of the positional relationship between the exit end of the adjustment member 30 and the incident end of the light guide 40 in Figure 1.

[0042] In Figure 6, as in the example shown in Figure 5, the boundary line 33 between the first region 31 and the second region 32 and the movement line L of the light guide 40 are non-parallel to each other. In addition, at least one point on the movement line L, the incident end of the light guide 40 may overlap the first region 31 and the second region 32. In Figure 6, unlike the example shown in Figure 5, the movement line L for the adjustment member 30 does not intersect the boundary line 33 between the first region 31 and the second region 32 inside the exit end of the adjustment member 30. In the example shown in Figure 6, the extension of the boundary line 33 intersects the movement line L outside the exit end of the adjustment member 30.

[0043] For example, when the boundary line 33 and the movement line L are parallel, the ratio of combinations of emission angles of the light incident from the adjustment member 30 to the rectangular array section 41 does not change. As a result, the light distribution of the illumination light emitted from the illumination device 1 does not change. Also, if the rectangular array section 41 never overlaps the first region 31 and the second region 32 simultaneously during movement, the light distribution of the illumination light emitted from the illumination device 1 does not change even when using an adjustment member 30 having two types of optical fiber bundles. As the movement line L is positioned relative to the boundary line 33 as shown in Figures 5 and 6, the ratio of combinations of emission angles of the light incident from the adjustment member 30 to the rectangular array section 41, and the amount of incident light, change as the rectangular array section 41 moves along the movement line L.

[0044] The relationship between the emission angle of the light source incident on the adjustment member 30, the aperture angle of the adjustment member 30, and the aperture angle of the light guide 40 will be explained. For example, the emission angle of the light source incident on the adjustment member 30 corresponds to the emission angle of the light guide fiber bundle 20. The first aperture angle of the first optical fiber bundle 34 is set to be smaller than the second aperture angle of the second optical fiber bundle 35.

[0045] In this case, the emission angle of the light guide fiber bundle 20 may be greater than the smallest first aperture angle in the adjustment member 30. In addition, the aperture angle of the light guide 40 may be greater than the first aperture angle. For example, the emission angle of the light guide fiber bundle 20 may be greater than or equal to the aperture angle of the light guide 40, and the aperture angle of the light guide 40 may be greater than or equal to the largest second aperture angle in the adjustment member 30. Furthermore, the aperture angle of the light guide 40 and the second aperture angle may be equal to each other.

[0046] For example, let α be the emission angle of the light guide fiber bundle 20, β1 be the first aperture angle, β2 be the second aperture angle, and γ be the aperture angle of the light guide 40. Here, β1 < β2. The combinations of α, γ, β1, and β2 that satisfy α > β1 and γ > β1, and the emission angles of the light guide 40 for each combination are listed below.

[0047] i) When γ > α > β2 > β1 Since α > β2 > β1, light with an incident angle of β1 propagates through the first optical fiber bundle 34 of the adjustment member 30, and light with an incident angle of β2 propagates through the second optical fiber bundle 35. Therefore, light with emission angles β1 and β2 is emitted from the output end of the adjustment member 30. Since γ > β2 > β1, light with incident angles β1 and β2 propagates through the light guide 40, and light with emission angles β1 and β2 is emitted from the output end of the light guide 40.

[0048] ii) When α > γ > β2 > β1. Since α > β2 > β1 and γ > β2 > β1, similar to case i), light with emission angles β1 and β2 is emitted from the adjustment member 30 and the light guide 40.

[0049] iii) When α > β2 > γ > β1. Since α > β2 > β1, similar to i), light with emission angles β1 and β2 is emitted from the output end of the adjustment member 30. Since β2 > γ > β1, light with incident angles β1 and γ propagates to the light guide 40, and light with emission angles β1 and γ is emitted from the output end of the light guide 40.

[0050] iv) When γ > β2 > α > β1. Since β2 > α > β1, light with an incident angle of β1 propagates through the first optical fiber bundle 34 of the adjustment member 30, and light with an incident angle of α propagates through the second optical fiber bundle 35. Therefore, light with emission angles β1 and α is emitted from the output end of the adjustment member 30. Since γ > α > β1, light with incident angles β1 and α propagates through the light guide 40, and light with emission angles β1 and α is emitted from the output end of the light guide 40.

[0051] v) When β2 > α > γ > β1 Since β2 > α > β1, similar to iv), light with emission angles β1 and α is emitted from the output end of the adjustment member 30. Since α > γ > β1, light with incident angles β1 and γ propagates to the light guide 40, and light with emission angles β1 and γ is emitted from the output end of the light guide 40.

[0052] vi) When β2 > γ > α > β1 Since β2 > α > β1, similar to iv), light with emission angles β1 and α is emitted from the emission end of the adjustment member 30. Since γ > α > β1, similar to iv), light with emission angles β1 and α is emitted from the emission end of the light guide 40.

[0053] Based on the above, the irradiation device 1 can emit light from the light guide fiber bundle 20 as light having two different emission angles by satisfying α > β1 and γ > β1.

[0054] In addition to α>β1 and γ>β1, if we add the relationship α≧γ and γ≧β2, the sign relationship of α, γ, β1, and β2 becomes α≧γ≧β2>β1. In this case, according to ii) above, light with emission angles β1 and β2 is emitted from the adjustment member 30 and the light guide 40. Therefore, when the relationship α≧γ and γ≧β2 is satisfied in addition to α>β1 and γ>β1, light with emission angles equal to the first and second aperture angles is emitted from the light guide 40. This shows that the emission angle of the illumination light emitted from the light guide 40 can be controlled by the aperture angle of the optical fiber bundle constituting the adjustment member 30.

[0055] In addition to the relationships α>β1 and γ>β1 and α≧γ and γ≧β2, if we add the relationship γ=β2, the sign relationship between α, γ, β1, and β2 becomes α≧γ=β2>β1. Since α>β2>β1, light with emission angles β1 and β2 is emitted from the emission end of the adjustment member 30.

[0056] According to the illumination device 1 of the first embodiment described above, the light distribution from the light guide 40 can be changed more flexibly even after the construction of the optical system including the light guide 40 and the observation system is completed. In the illumination device 1, the adjustment member 30 is positioned between the light source and the light guide 40 so that the relative position between the adjustment member 30 and the light guide 40 is variable. As a result, the illumination device 1 can easily change the light distribution from the light guide 40 by changing the relative position of the light guide 40 with respect to the adjustment member 30.

[0057] Even after the optical system has been constructed, the illumination device 1 can adjust the aperture angle of the light incident on the light guide 40 according to the relative position of the light guide 40 with respect to the adjustment member 30. Therefore, the illumination device 1 does not need to use a different light guide 40 for each subject to be observed, which can reduce costs. By appropriately selecting the combination of optical fiber types for the adjustment member 30 located upstream of the light guide 40, the illumination device 1 can also irradiate illumination light from the light guide 40 with a variety of aperture angle combinations compared to conventional technology. For example, the illumination device 1 can also configure the adjustment member 30 with an optical fiber having a single aperture angle, allowing for flexible handling even when it is necessary to irradiate illumination light with a single aperture angle.

[0058] The adjustment member 30 is detachably positioned relative to the light source and the light guide 40. This allows the user to easily replace the adjustment member 30 with a different type, even when the illumination device 1 is irradiating the object under observation with illumination light. Since the light distribution of the illumination light emitted from the light guide 40 changes depending on the type of adjustment member 30, the user can easily obtain the desired light distribution by incorporating the appropriate type of adjustment member 30 into the illumination device 1. By replacing the adjustment member 30, which is located further away from the object under observation, rather than the light guide 40, which is located closer to the object under observation, the user can reduce damage to the object under observation and make the replacement process easier.

[0059] The size of the light source and the distance between the adjustment member 30 and the light source are determined so that the light emitted from the light source illuminates the entire effective diameter of the adjustment member 30. This allows the irradiation device 1 to emit light from all the optical fibers constituting the adjustment member 30 at the output end of the adjustment member 30. Therefore, the irradiation device 1 can more efficiently couple the light from the adjustment member 30 to the light guide 40.

[0060] The adjustment member 30 includes a first optical fiber and a second optical fiber with different aperture angles. This allows the illumination device 1 to emit illumination light from the light guide 40 using a combination of two different aperture angles.

[0061] In a front view of the output end of the adjustment member 30, the first optical fiber is positioned only in the first region 31 at the output end, and the second optical fiber is positioned only in the second region 32 adjacent to the first region 31 at the output end. This allows the irradiation device 1 to clearly separate the portion of the adjustment member 30 having a first aperture angle from the portion having a second aperture angle. Therefore, the irradiation device 1 makes it easier to control the light distribution from the light guide 40 by changing the relative position between the adjustment member 30 and the light guide 40.

[0062] The end face shape of the incident end of the light guide 40 is contained within the shape of the region with the smaller area of ​​the first region 31 and the second region 32. This makes it possible for the illumination device 1 to receive only the light from the first optical fiber of the adjustment member 30 with the light guide 40 and to irradiate illumination light from the light guide 40 only at the first aperture angle. Conversely, it is also possible for the illumination device 1 to receive only the light from the second optical fiber of the adjustment member 30 with the light guide 40 and to irradiate illumination light from the light guide 40 only at the second aperture angle.

[0063] The area of ​​the incident end of the light guide 40 is smaller than the area of ​​the first region 31 and the second region 32, respectively. This makes it possible for the illumination device 1 to receive only the light from the first optical fiber of the adjustment member 30 with the light guide 40 and to irradiate illumination light from the light guide 40 only at the first aperture angle. Conversely, it is also possible for the illumination device 1 to receive only the light from the second optical fiber of the adjustment member 30 with the light guide 40 and to irradiate illumination light from the light guide 40 only at the second aperture angle.

[0064] The emission end of the adjustment member 30 is equally divided by the first region 31 and the second region 32. As a result, the irradiation device 1 has S1≧S2≧S L Even if the relationship holds, the area S of the incident end of the rectangular array section 41 L This allows the light intensity of the illumination light emitted from the light guide 40 to be maintained, thereby avoiding a reduction in the amount of light incident on the light guide 40.

[0065] The boundary line 33 between the first region 31 and the second region 32 and the movement line L of the light guide 40 are non-parallel to each other, and at least one point on the movement line L, the incident end of the light guide 40 overlaps the first region 31 and the second region 32. This makes it possible for the illumination device 1 to simultaneously couple light emitted from the adjustment member 30 at different aperture angles to the light guide 40. Therefore, it is also possible for the illumination device 1 to simultaneously irradiate with illumination light at different aperture angles.

[0066] The line of movement L relative to the adjustment member 30 intersects the boundary line 33 between the first region 31 and the second region 32 inside the exit end of the adjustment member 30. This allows the illumination device 1 to receive light emitted from the adjustment member 30 at different aperture angles across the entire light guide 40 and simultaneously combine that light across the entire light guide 40. Therefore, the illumination device 1 can obtain a greater amount of light when simultaneously irradiating with illumination light at different aperture angles.

[0067] At least a portion of the incident end of the light guide 40 overlaps with the outgoing end of the adjustment member 30. This allows the illumination device 1 to achieve optical coupling between the adjustment member 30 and the light guide 40, enabling the control of the light distribution from the light guide 40 as described above. By having the entire incident end of the light guide 40 overlap with the outgoing end of the adjustment member 30, the illumination device 1 can emit illumination light with a greater amount of light from the light guide 40.

[0068] The emission angle of the light source is greater than the smallest first aperture angle at the adjustment member 30, and the aperture angle of the light guide 40 is greater than the first aperture angle. As a result, as described above in i) to vi), the illumination device 1 can also emit illumination light from the light guide 40 using a combination of two different aperture angles.

[0069] The emission angle of the light source is greater than or equal to the aperture angle of the light guide 40, and the aperture angle of the light guide 40 is greater than or equal to the largest second aperture angle in the adjustment member 30. As a result, as described above, the illumination device 1 can also emit illumination light from the light guide 40 using a combination of the first and second aperture angles. Therefore, the illumination device 1 can control the emission angle of the illumination light emitted from the light guide 40 by the aperture angle of the optical fiber bundle constituting the adjustment member 30.

[0070] The aperture angle of the light guide 40 and the second aperture angle are equal to each other. As a result, as described above, the illumination device 1 can also emit illumination light from the light guide 40 using a combination of the first and second aperture angles. Therefore, the illumination device 1 can control the emission angle of the illumination light emitted from the light guide 40 by the aperture angle of the optical fiber bundle constituting the adjustment member 30.

[0071] In the first embodiment described above, the adjustment member 30 is described as being detachably arranged with respect to the light source and the light guide 40, but this is not limited to this. The adjustment member 30 may be in a non-detachably arranged manner with respect to the light source and the light guide 40.

[0072] In the first embodiment described above, the size of the light source and the distance between the adjusting member 30 and the light source were determined so that the light emitted from the light source illuminates the entire effective diameter of the adjusting member 30, but this is not limited to this. The light emitted from the light source does not have to illuminate the entire effective diameter of the adjusting member 30.

[0073] In the first embodiment described above, the adjustment member 30 was described as including a first optical fiber and a second optical fiber having different aperture angles, but it is not limited to this. The adjustment member 30 may include three or more types of optical fibers having different aperture angles.

[0074] In the first embodiment described above, it was explained that, in a front view of the output end of the adjustment member 30, the first optical fiber is arranged only in the first region 31 of the output end, and the second optical fiber is arranged only in the second region 32 adjacent to the first region 31 at the output end. However, the embodiment is not limited to this. The first optical fiber and the second optical fiber do not necessarily have to be separated into regions at the output end of the adjustment member 30.

[0075] In the first embodiment described above, the end face shape of the incident end of the light guide 40 was described as being within the shape of the region with the smaller area among the first region 31 and the second region 32, but this is not limited to this. The end face shape of the incident end of the light guide 40 does not have to be within the shape of the region with the smaller area among the first region 31 and the second region 32.

[0076] In the first embodiment described above, the area of ​​the incident end of the light guide 40 was described as being smaller than the area of ​​the first region 31 and the second region 32, but this is not limited to that. The area of ​​the incident end of the light guide 40 may be greater than or equal to the area of ​​at least one of the first region 31 and the second region 32.

[0077] In the first embodiment described above, the exit end of the adjustment member 30 is described as being equally divided by a first region 31 and a second region 32, but this is not limited to this. The exit end of the adjustment member 30 may be divided by the first region 31 and the second region 32 in such a way that the area is uneven. The exit end of the adjustment member 30 is not limited to two regions, but may be divided by three or more regions in such a way that the area is equal or uneven.

[0078] In the first embodiment described above, the boundary line 33 between the first region 31 and the second region 32 and the movement line L of the light guide 40 are non-parallel to each other, and the incident end of the light guide 40 overlaps the first region 31 and the second region 32 at at least one point on the movement line L. However, the embodiment is not limited to this. The arrangement relationship between the boundary line 33 and the movement line L may be arbitrarily determined according to the number of boundary lines 33, etc., as long as control of the light distribution by the illumination device 1 is achievable.

[0079] In the first embodiment described above, the movement line L for the adjustment member 30 is described as intersecting the boundary line 33 between the first region 31 and the second region 32 inside the exit end of the adjustment member 30, as shown in Figure 5, but is not limited to this. The movement line L for the adjustment member 30 does not have to intersect the boundary line 33 between the first region 31 and the second region 32 inside the exit end of the adjustment member 30, as shown in Figure 6.

[0080] In the first embodiment described above, at least a portion of the incident end of the light guide 40 overlaps with the exit end of the adjustment member 30, but this is not limited to this. At least a portion of the incident end of the light guide 40 does not have to overlap with the exit end of the adjustment member 30. For example, other optical elements such as a mirror and a lens may be placed between the adjustment member 30 and the light guide 40, so that the adjustment member 30 and the light guide 40 are spaced apart from each other.

[0081] In the first embodiment described above, the emission angle of the light source is greater than the smallest first aperture angle in the adjustment member 30, and the aperture angle of the light guide 40 is greater than the first aperture angle; however, this is not limited to this. The irradiation device 1 may satisfy other angular conditions as long as it can control the light distribution from the light guide 40.

[0082] In the first embodiment described above, the emission angle of the light source is greater than or equal to the aperture angle of the light guide 40, and the aperture angle of the light guide 40 is greater than or equal to the largest second aperture angle in the adjustment member 30. However, the invention is not limited to this. The irradiation device 1 may satisfy other angular conditions as long as it can control the light distribution from the light guide 40.

[0083] In the first embodiment described above, the aperture angle of the light guide 40 and the second aperture angle were described as being equal to each other, but this is not limited to this. The aperture angle of the light guide 40 and the second aperture angle may be different from each other, as long as the illumination device 1 can control the light distribution from the light guide 40.

[0084] In the first embodiment described above, the light-guiding fiber bundle 20 and the adjustment member 30 are directly optically coupled, but the embodiment is not limited to this. Other optical elements such as mirrors and lenses may be placed between the light-guiding fiber bundle 20 and the adjustment member 30.

[0085] In the first embodiment described above, the diameter of the optical fiber constituting the adjustment member 30 may be arbitrarily determined as long as the irradiation device 1 can achieve the above-described control of the light distribution. Similarly, the diameter of the optical fiber constituting the light guide 40 may be arbitrarily determined as long as the irradiation device 1 can achieve the above-described control of the light distribution.

[0086] In the first embodiment described above, the number of optical fibers constituting the adjustment member 30 may be one or more for each type corresponding to each aperture angle. Similarly, the number of optical fibers constituting the light guide 40 may be one or more.

[0087] (Second Embodiment) In the irradiation device 1 according to the second embodiment of this disclosure, the adjustment member 30 differs from the first embodiment in that it includes only a plurality of optical fibers having the same aperture angle, rather than including first and second optical fibers having different aperture angles. Other configurations, functions, effects, and modifications are the same as in the first embodiment, and corresponding descriptions also apply to the irradiation device 1 according to the second embodiment. In the following, components the same as in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted. The differences from the first embodiment will be mainly described.

[0088] If only one emission angle of illumination light emitted from the light guide 40 is required, the aperture angles of the optical fibers constituting the adjustment member 30 may also be the same in order to ensure that the emission angle of illumination light emitted from the light guide 40 is limited to the desired single angle. This allows the illumination device 1 to flexibly respond even when it is necessary to irradiate with illumination light at a single aperture angle. In the second embodiment as well, at least a portion of the incident end of the light guide 40 may overlap with the emission end of the adjustment member 30. This ensures that the light emitted from the emission end of the adjustment member 30 is reliably incident on the light guide 40. [Examples]

[0089] An embodiment of the irradiation device 1 according to the first embodiment will be described.

[0090] (Example 1) As the irradiation device 1 according to Example 1, an irradiation device 1 having the same configuration as the irradiation device 1 of the first embodiment described with reference to Figure 1 was manufactured.

[0091] First, the adjustment member 30 will be described. A circular first optical fiber bundle consisting of approximately 2500 first optical fibers (SOG-35, manufactured by Sumida Optical Glass Co., Ltd.) with an aperture angle of 35° and a circular second optical fiber bundle consisting of approximately 1450 second optical fibers (SOG-120C, manufactured by Sumida Optical Glass Co., Ltd.) with an aperture angle of 120° was fabricated. Next, each optical fiber bundle was cut in half by a straight line passing through the center of the end face. The divided surfaces of each halved optical fiber bundle were bonded together to form the adjustment member 30. To prevent crosstalk between optical fibers with different aperture angles, the bonding surfaces were painted with black ink. Furthermore, the area occupied by the first optical fiber with an aperture angle of 35° at the output end of the adjustment member 30 was designated as the first region 31, and the area occupied by the second optical fiber with an aperture angle of 120° was designated as the second region 32. Figure 7 shows a front view of the output end of the adjustment member 30 fabricated in Example 1. The maximum outer diameter of the output end of this adjustment member 30 (horizontal direction in Figure 7) was approximately 4.48 mm, and the minimum value (vertical direction in Figure 7) was approximately 3.95 mm. Furthermore, the total number of optical fibers constituting this adjustment member 30 was approximately 1900.

[0092] The light guide 40 is described below. The light guide 40 is a rectangular light guide with a rectangular cross-section at its entrance end, as shown in Figure 8. The rectangular light guide is made of bundled SOG-120C optical fibers manufactured by Sumida Optical Glass Co., Ltd. Using optical fibers with an aperture angle of 120°, the entrance end of the light guide 40 is a rectangular arrangement section 41, with optical fibers having an outer diameter of 50 μm arranged in a rectangular arrangement section measuring 3.22 mm vertically and 0.23 mm horizontally, as shown in Figure 8, so that the distance between the centers of the cores is 50 μm. The diameter of the light guide 40 outside of the rectangular arrangement section 41 was 2.0 mm. The total number of optical fibers constituting this light guide 40 was 320.

[0093] A light source 10 containing a white LED was pressed against a light guide fiber bundle 20. The light guide fiber bundle 20 is a light guide made by bundling SOG-120C optical fibers manufactured by Sumida Optical Glass Co., Ltd. The light source 10 used in Example 1 has an emission angle of 180°, and emits light forward. The distance between the emission end of the light guide fiber bundle 20 and the adjustment member 30 was determined so that when light is emitted from the light source 10, the light from the emission end of the light guide fiber bundle 20 illuminates the entire effective diameter of the adjustment member 30. In Example 1, the adjustment member 30 was fixed, and the rectangular arrangement section 41, which is the incident end of the light guide 40, was made movable relative to the adjustment member 30. In this way, an illumination device 1 according to the configuration of Figure 1 was manufactured.

[0094] Here, the emission angle of the light guide fiber bundle 20 is 120°. Also, the first aperture angle of the adjustment member 30 is 35°, the second aperture angle is 120°, and the aperture angle of the light guide 40 is 120°. Therefore, the emission angle of the light guide fiber bundle 20 is greater than the first aperture angle, and the aperture angle of the light guide 40 is greater than the first aperture angle. Furthermore, the emission angle of the light guide fiber bundle 20 is greater than or equal to the aperture angle of the light guide 40, and the aperture angle of the light guide 40 is greater than or equal to the second aperture angle. Moreover, the aperture angle of the light guide 40 and the second aperture angle are equal to each other.

[0095] (Evaluation of light distribution characteristics) Figure 9 shows the positional relationship between the exit end of the adjustment member 30 and the incident end of the rectangular array section 41 when evaluating the light distribution characteristics of the irradiation device 1 fabricated in Example 1. Here, since the optical fiber bundles that were cut in half were bonded together, the boundary line 33 between the first region 31 and the second region 32 was considered to be a straight line. The movement line L of the incident end of the rectangular array section 41 was defined as a straight line passing through the center of the exit end of the adjustment member 30 and having an inclination of 45° with respect to the boundary line 33. Using the center of the exit end of the adjustment member 30 as the base point, the rectangular array section 41 was moved ±1.30 mm along the movement line L, and the light distribution of the illumination light emitted from the exit end of the light guide 40 was measured every 0.20 mm. As shown in Figure 9, in Example 1, the overlap area between the first region 31 and the incident end of the rectangular array section 41 was largest when the rectangular array section 41 was at a position of +1.30 mm on the movement line L. On the other hand, when the rectangular array section 41 was at a position of -1.30 mm from the movement line L, the overlap area between the second region 32 and the incident end of the rectangular array section 41 was the largest.

[0096] Figure 10A shows an image of the rectangular array section 41 being placed in close contact with the movement line L at a position of +1.30 mm. Figure 10B shows an image of the rectangular array section 41 being placed in close contact with the movement line L at a position of -1.30 mm. In both Figures 10A and 10B, the center represents the adjustment member 30, and the vertical black lines enclosed in a square frame indicate the arrangement of multiple optical fibers at the incident end of the light guide 40.

[0097] The measurement system and method for measuring the light distribution of the light guide 40 will be explained using Figure 11. The optical axis of the illumination light emitted from the exit end of the light guide 40 was defined as the optical axis u. A straight line located 52 mm from the exit end of the light guide 40 and perpendicular to the optical axis u was defined as the movement line m of the power meter 50. As shown in Figure 11, using the intersection of the optical axis u and the movement line m as the base point, the point 90 mm to the left on the movement line m was defined as the "start" point of the power meter 50, and the point 90 mm to the right was defined as the "finish" point of the power meter 50. The power meter 50 moving along the movement line m is to rotate at an appropriate angle so that the light-receiving surface of the power meter 50 is perpendicular to the line connecting the center of the exit end of the light guide 40 and the center of the light-detecting part of the power meter 50.

[0098] The measurement procedure is explained in the following steps. In Figure 11, the rectangular array section 41 is positioned at +1.30 mm from the movement line L as the "initial position" and at -1.30 mm as the "end position". First, the rectangular array section 41 was placed at the "initial position" (step 1). The light intensity of the light source 10, including the white LED, was adjusted so that sufficient light could be detected by the power meter 50 (step 2). In Figure 11, the power meter 50 was placed at the "start" point (step 3). The light intensity detected by the power meter 50 was recorded (step 4). The power meter 50 was moved 1 mm to the right on the movement line m (step 5). Steps 4 and 5 were repeated until the power meter 50 was positioned at the "finish" point (step 6). The rectangular array section 41 was moved 0.2 mm from the "initial position" towards the "end" point on the movement line L (step 7). Steps 3 to 6 were performed (step 8). Steps 7 and 8 were repeated until the rectangular array section 41 reached the "end" (step 9).

[0099] Figure 12 shows the measurement results. The horizontal axis represents the angle between the line connecting the exit end of the light guide 40 and the power meter 50 and the optical axis u. The vertical axis represents the relative value of the optical power measured at each position of the power meter 50 at the position of the rectangular array section 41. When the rectangular array section 41 is positioned in the "initial position," the most light emitted from the first optical fiber bundle 34 (aperture angle 35°) of the adjustment member 30 enters the light guide 40 (aperture angle 120°), so the ratio of the exit angle of the illumination light emitted from the light guide 40 is largest at 35°. On the other hand, when the rectangular array section 41 is positioned in the "termination" position, the most light emitted from the second optical fiber bundle 35 (aperture angle 120°) of the adjustment member 30 enters the light guide 40 (aperture angle 120°), so the ratio of the exit angle of the illumination light emitted from the light guide 40 is largest at 120°. Figure 12 shows that moving the rectangular array section 41 changes the light distribution of the illumination light emitted from the light guide 40.

[0100] Light emitted at an angle of 35° travels in a straighter line and does not disperse over a wider area compared to light emitted at an angle of 120°. As shown in Figure 12, when the rectangular array section 41 is in its "initial position" (+1.30 mm), the difference in light intensity when the horizontal axis angle is ±30° and 0° is approximately 10 times. On the other hand, when the rectangular array section 41 is at its "end" position (-1.30 mm), the difference in light intensity when the horizontal axis angle is ±30° and 0° is approximately 1.7 times. From this, it can be seen that if you want to brightly illuminate an object to be observed at a distance, you should place the rectangular array section 41 in its "initial position," and conversely, if you want to illuminate an object to be observed at a close distance without causing halation, you should place the rectangular array section 41 in its "end." It was shown that the closer the rectangular array section 41 is to its "initial position," the narrower the illumination angle of the emitted light becomes, and the closer it is to its "end," the wider the illumination angle of the emitted light becomes.

[0101] (Example 2) In Example 2, an observation unit 60, an image guide 70, an image sensor unit 80, and an observation monitor 90 were added to the configuration of the irradiation device 1 of Example 1, and a 4 mm inner diameter tube 100 with a monochrome chart drawn on its inner surface was observed. A schematic diagram showing the configuration of the irradiation device 1 of Example 2 is shown in Figure 13. Image information of the inner surface of the 100 tube irradiated with light emitted from the light guide 40 was transmitted to the image sensor unit 80 by the image guide 70, and the image was processed and observed on the observation monitor 90.

[0102] The light source 10 and the light guide fiber bundle 20 were the same as those used in Example 1. The adjustment member 30 consisted of a halved first optical fiber bundle 34 and a second optical fiber bundle 35, with a first aperture angle of 35° and a second aperture angle of 120°. The first optical fiber bundle 34 was placed in the first region 31, and the second optical fiber bundle 35 was placed in the second region 32. The maximum outer diameter of the adjustment member 30 in Example 2 was approximately 4.48 mm, and the minimum was approximately 3.95 mm. The total number of optical fibers constituting this adjustment member 30 was approximately 1900. An optical fiber with an aperture angle of 120° was used as the light guide 40, and the incident end was a rectangular arrangement section 41 with a vertical dimension of 3.50 mm and a horizontal dimension of 0.28 mm.

[0103] The observation unit 60 is formed by combining the optical fiber constituting the light guide 40 and the tip of the image guide 70. The tip of the image guide 70 refers to the end opposite to the end that is in contact with the image sensor unit 80. Figure 14A shows a front view of the observation unit 60, and Figure 14B shows a schematic diagram of the end face of the observation unit 60. In the observation unit 60, the optical fiber constituting the light guide 40 is arranged so as to surround the tip portion of the image guide 70, which has a diameter of 0.35 mm, forming a cylinder with a total diameter of 1.23 mm. Furthermore, when the surrounding covering to protect the light guide 40 and image guide 70 is added, the total diameter of the cylinder is 2.23 mm. A lens with a field of view of approximately 90° is mounted at the tip of the image guide 70.

[0104] The rectangular array section 41 was moved relative to the exit end of the adjustment member 30, and the inside of the thin tube 100 was observed. Similar to Example 1, a straight line passing through the center of the exit end of the adjustment member 30 and having a 45° inclination with respect to the boundary line 33 was defined as the movement line L of the incident end of the rectangular array section 41. As shown in Figure 15, images were acquired on the observation monitor 90 when the rectangular array section 41 was positioned at 0 mm, ±0.5 mm, and ±1.0 mm on the movement line L, with the center of the exit end of the adjustment member 30 as the base point. When the rectangular array section 41 was at +1.0 mm on the movement line L, the overlap area between the first region 31 and the incident end of the rectangular array section 41 was the largest. On the other hand, when the rectangular array section 41 was at -1.0 mm on the movement line L, the overlap area between the second region 32 and the incident end of the rectangular array section 41 was the largest. Figures 16(a) to (e) are images of the tubular tube 100 at -1.0 mm, -0.5 mm, 0 mm, +0.5 mm, and +1.0 mm, respectively.

[0105] From the results of Example 1, the irradiation angle of the light emitted from the light guide 40 is widest when the rectangular array section 41 is at a position of -1.0 mm, and the irradiation angle narrows as it approaches +1.0 mm. In the image of Figure 16(a), light does not reach at a greater distance, while the area closer to the object (the edge of the image) is bright and clear. In contrast, in the image of Figure 16(e), compared to Figure 16(a), light reaches further (to the center of the image), while the area closer to the object appears dark. This is consistent with the results of Example 1. From these results, it has been shown that the irradiation angle of the illumination light emitted by the irradiation device 1 can be adjusted by selecting an appropriate adjustment member 30 according to the position of the object to be observed or the required brightness.

[0106] It will be obvious to those skilled in the art that this disclosure can be implemented in other predetermined forms besides the embodiments and examples described above without deviating from its spirit or essential features. Therefore, the prior description is illustrative and not limiting. The scope of the disclosure is defined not by the prior description but by the added claims. Any modifications within their equivalent scope are included therein.

[0107] For example, the shape, pattern, size, arrangement, orientation, type, and number of each component described above are not limited to those shown in the above description and drawings. The shape, pattern, size, arrangement, orientation, type, and number of each component may be configured arbitrarily as long as they can realize their function. The components of the irradiation device 1 shown are functional concepts, and the specific form of each component is not limited to those shown.

[0108] Some embodiments of the present disclosure are described below. However, it should be noted that the embodiments of the present disclosure are not limited to these. [Note 1] Light source and An adjustment member including at least one of several types of optical fibers having different aperture angles, A light guide containing only at least one optical fiber with identical aperture angles, Equipped with, The adjustment member is positioned between the light source and the light guide such that the relative position between the adjustment member and the light guide is variable. Irradiation device. [Note 2] The irradiation device described in Appendix 1, The adjustment member is detachably arranged with respect to the light source and the light guide. Irradiation device. [Note 3] An irradiation device as described in Appendix 1 or 2, The size of the light source and the distance between the adjusting member and the light source are determined so that the light emitted from the light source illuminates the entire effective diameter of the adjusting member. Irradiation device. [Note 4] An irradiation device as described in any one of the appendices 1 to 3, The adjustment member includes a first optical fiber and a second optical fiber having different aperture angles. Irradiation device. [Note 5] The irradiation device described in Appendix 4, In a front view of the output end of the adjustment member, the first optical fiber is arranged only in a first region of the output end, and the second optical fiber is arranged only in a second region adjacent to the first region at the output end. Irradiation device. [Note 6] The irradiation device described in Appendix 5, The end face shape of the incident end of the light guide is contained within the shape of the region with the smaller area among the first and second regions. Irradiation device. [Note 7] The irradiation device described in Appendix 6, The area of ​​the incident end is smaller than the area of ​​the first region and the second region, Irradiation device. [Note 8] An irradiation device as described in any one of the appendices 5 to 7, The exit end is equally divided by the first region and the second region. Irradiation device. [Note 9] An irradiation device as described in any one of the appendices 5 to 8, The boundary line between the first region and the second region and the movement line of the light guide are non-parallel to each other, and at least one point on the movement line, the incident end of the light guide overlaps the first region and the second region. Irradiation device. [Note 10] The irradiation device described in Appendix 9, The movement line for the adjustment member intersects the boundary line between the first region and the second region within the exit end. Irradiation device. [Note 11] An irradiation device as described in any one of the appendices 1 to 3, The adjustment member includes only a plurality of optical fibers having the same aperture angle. Irradiation device. [Note 12] An irradiation device as described in any one of the appendices 1 to 11, At least a portion of the incident end of the light guide overlaps with the exit end of the adjustment member. Irradiation device. [Note 13] An irradiation device as described in any one of the appendices 1 to 12, The emission angle of the light source is greater than the smallest first aperture angle in the adjustment member. The aperture angle of the light guide is greater than the first aperture angle. Irradiation device. [Note 14] The irradiation device described in Appendix 13, The emitted light angle is greater than or equal to the aperture angle of the light guide, and the aperture angle of the light guide is greater than or equal to the second largest aperture angle in the adjustment member. Irradiation device. [Note 15] The irradiation device described in Appendix 14, The aperture angle of the light guide and the second aperture angle are equal to each other. Irradiation device. [Explanation of symbols]

[0109] 1 Irradiation device 10 light source 20 Fiber guiding bundles 30 Adjustment Member 31 First area 32 Second area 33 Boundary Line 34. First Fiber Optic Bundle 35. Second Fiber Optic Bundle 40 Light Guide 41 Rectangular arrangement section 50 Power Meter 60 Observation Section 70 Image Guide 80 Image sensor section 90 Observation Monitor 100 tubular L moving line m moving line u optical axis

Claims

1. Light source and An adjustment member including at least one of several types of optical fibers having different aperture angles, A light guide containing only at least one optical fiber with identical aperture angles, Equipped with, The adjustment member is positioned between the light source and the light guide such that the relative position between the adjustment member and the light guide is variable. Irradiation device.

2. The irradiation device according to claim 1, The adjustment member is detachably arranged with respect to the light source and the light guide. Irradiation device.

3. An irradiation device according to claim 1 or 2, The size of the light source and the distance between the adjusting member and the light source are determined so that the light emitted from the light source illuminates the entire effective diameter of the adjusting member. Irradiation device.

4. An irradiation device according to claim 1 or 2, The adjustment member includes a first optical fiber and a second optical fiber having different aperture angles. Irradiation device.

5. The irradiation device according to claim 4, In a front view of the output end of the adjustment member, the first optical fiber is arranged only in a first region of the output end, and the second optical fiber is arranged only in a second region adjacent to the first region at the output end. Irradiation device.

6. The irradiation device according to claim 5, The end face shape of the incident end of the light guide is contained within the shape of the region with the smaller area among the first region and the second region. Irradiation device.

7. The irradiation device according to claim 6, The area of ​​the incident end is smaller than the area of ​​the first region and the second region, Irradiation device.

8. The irradiation device according to claim 5, The exit end is equally divided by the first region and the second region. Irradiation device.

9. The irradiation device according to claim 5, The boundary line between the first region and the second region and the movement line of the light guide are non-parallel to each other, and at least one point on the movement line, the incident end of the light guide overlaps the first region and the second region. Irradiation device.

10. The irradiation device according to claim 9, The movement line for the adjustment member intersects the boundary line between the first region and the second region within the exit end. Irradiation device.

11. An irradiation device according to claim 1 or 2, The adjustment member includes only a plurality of optical fibers having the same aperture angle. Irradiation device.

12. An irradiation device according to claim 1 or 2, At least a portion of the incident end of the light guide overlaps with the exit end of the adjustment member. Irradiation device.

13. An irradiation device according to claim 1 or 2, The emission angle of the light source is greater than the smallest first aperture angle in the adjustment member. The aperture angle of the light guide is greater than the first aperture angle. Irradiation device.

14. The irradiation device according to claim 13, The emitted light angle is greater than or equal to the aperture angle of the light guide, and the aperture angle of the light guide is greater than or equal to the second largest aperture angle in the adjustment member. Irradiation device.

15. The irradiation device according to claim 14, The aperture angle of the light guide and the second aperture angle are equal to each other. Irradiation device.

Images