JP2013090674A - Endoscopic illumination device and endoscope device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscopic illumination device which can have a configuration having a high degree of freedom in design by improving light-emission efficiency by enabling a configuration in which a phosphor is sealed with a resin material in a light-emitting member; and to provide an endoscope device.SOLUTION: The endoscopic illumination device irradiates a subject with illumination light through illumination windows 43A, 43B formed on a distal end of an endoscope insertion portion. The endoscopic illumination device includes: a blue semiconductor light source LD1; a red semiconductor light source LD2; a light guide member 55 for guiding blue and red light to the illumination windows; and light-emitting members 57A, 57B which are disposed on light-emission end of the light guide member inside the illumination windows, and include a green phosphor not substantially absorbing the red light but transmitting it, absorbing part of the blue light as an excitation light to emit green-based fluorescence and transmitting part of the residue. The green phosphor is sealed with a resin material in the light-emitting member.

Description

  The present invention relates to an endoscope illumination device and an endoscope device.

  As a light source device for an endoscope, a white lamp such as a xenon lamp is widely used as a light emission source. In recent years, those using high-efficiency and high-intensity laser light have been developed. As a white light source using laser light, for example, there is a laser white light source including a blue laser light source and a light emitting member that emits blue laser light as excitation light. The light-emitting member in this case includes a green-emitting green phosphor and a red-emitting red phosphor. Each phosphor receives excitation light and emits green and red light. The laser white light source mixes light emitted from these phosphors and blue light generated by blue laser light to cause the entire light emitting member to emit white light, thereby generating white illumination light.

  When the above light emitting member is arranged at the tip of the endoscope insertion portion and the laser white light source is mounted on the endoscope apparatus, it is necessary to make the light emitting member as small as possible in order to reduce the diameter of the endoscope insertion portion. There is. However, when the outer diameter of the light emitting member is reduced to, for example, φ1 mm or less, and the laser beam is irradiated to the reduced minute spot, the light emitting member is excited by the laser light and generates heat. The heat generated at this time may reach about 150 ° C. even when the output of the endoscope apparatus is about 150 to 200 mW (one lamp).

  For example, when a silicone resin such as phenyl silicone is used as the phosphor sealing material, decomposition of the resin proceeds when the light emitting member reaches the above-described high temperature. Also, volatilization of solvents such as methanol, ethanol, normal hexane, and benzene begins. Therefore, in general, as a light emitting member in the case of using laser light, a phosphor is mixed in a heat-resistant glass powder (low melting point glass such as silicate glass) and heated and sintered (Patent Document 1). reference).

  However, when the phosphor is heated and sintered with the glass powder, the phosphor is exposed to heat as high as 600 ° C. and is thermally damaged, resulting in a decrease in luminous efficiency. Moreover, since heat resistance is required, there is a disadvantage that the material choices of the phosphor are narrowed.

  Further, the emission efficiency of the fluorescent part chamber decreases due to the Stokes loss as the emission wavelength becomes farther from the excitation light wavelength. For this reason, the use of a phosphor emitting red light with respect to blue excitation light itself becomes a factor of reducing luminous efficiency. Further, the light emission characteristics of the phosphor have temperature dependence, and the balance between the green (yellow) light emission intensity and the red light emission intensity changes as the temperature of the light emitting member increases due to light emission. As a result, the color of the emitted light changes due to the temperature change of the light emitter, and the color tone of the illumination light changes.

  In order to prevent the above-mentioned color change of light emission, it is not only to determine the combination of phosphors to be used, but also to determine the change in the light emission efficiency due to the temperature change of each phosphor. Must be set the same. However, as shown in FIG. 16, the luminous efficiency of the phosphors of the respective colors as the temperature rises exhibits different curves for each color. That is, as the temperature rises, the luminous efficiency of the red light emitting phosphor becomes lower than that of the green light emitting phosphor, and the R: B ratio, which is the light emission amount ratio, becomes lower than the G: B ratio.

  The temperature dependence of the phosphor emission can be reduced to some extent by selecting the phosphor material, but the degree of freedom in selecting the phosphor material is impaired. For example, when α-sialon (green light-emitting phosphor) having high luminous efficiency is used instead of YAG (yttrium, aluminum, garnet) phosphor, red having high temperature efficiency and the same temperature characteristics as α-sialon. There are no luminescent phosphors. For this reason, phosphors having similar characteristics must be substituted, resulting in a decrease in luminous efficiency and an increase in variation.

  Further, resin materials for sealing phosphors generally have a trade-off relationship between light durability by laser light and moisture resistance. Since the resin material having high moisture resistance has low light durability, it is applied to portions other than the outgoing optical path and the use range is limited.

Japanese Patent No. 4638837

  The present invention provides an endoscope illumination device and an endoscope device that can be configured to have high luminous efficiency and a high degree of design freedom by adopting a configuration in which a phosphor is sealed with a resin material in a light emitting member. For the purpose.

The present invention has the following configuration.
(1) An endoscope illumination device that irradiates illumination light toward an object from an illumination window provided at a distal end of an endoscope insertion portion,
A blue semiconductor light source that generates blue light;
A red semiconductor light source that generates red light; and
A light guide member for guiding blue light from the blue semiconductor light source and red light from the red semiconductor light source;
A light emitting member disposed facing the light exit end of the light guide member inside the illumination window;
With
The light emitting member includes a green phosphor that transmits the red light substantially without absorbing it, absorbs part of the blue light as excitation light, emits green-based fluorescence, and transmits the remaining part. Consists of
An endoscope illumination device in which the green phosphor is sealed with a resin material in the light emitting member.
(2) An endoscope apparatus equipped with the endoscope illumination apparatus according to (1).

  The endoscope illumination device and the endoscope device according to the present invention can be configured with a high degree of design freedom by increasing the light emission efficiency by sealing the phosphor with a resin material in the light emitting member.

It is a figure for describing an embodiment of the present invention, and is a lineblock diagram of an endoscope apparatus showing each apparatus to which an endoscope and an endoscope are connected. It is an external view which shows the specific structural example of an endoscope apparatus. It is an external appearance perspective view of an endoscope front-end | tip part. It is a graph which shows the spectral characteristic of the emitted light from a light emitting member. (A) is a schematic block diagram schematically showing the first light emitting member, (B) is a schematic block diagram schematically showing the second light emitting member, and (C) schematically shows the third light emitting member. It is a schematic block diagram. (A) is a schematic block diagram schematically showing a fourth light emitting member, (B) is a schematic block diagram schematically showing a fifth light emitting member, and (C) schematically shows a sixth light emitting member. It is a schematic block diagram. It is a schematic block diagram which shows a 7th light emission member typically. It is a graph which shows the transmittance | permeability with respect to the wavelength of a fluorescent reflective film, and the characteristic of a reflectance. It is a schematic block diagram which shows typically an 8th light emitting member. It is a schematic block diagram which shows the 9th light emitting member typically. It is a schematic block diagram which shows typically the 10th light emitting member. It is explanatory drawing which shows the characteristic of the resin material which seals fluorescent substance, and is a graph which shows the relationship between light durability and moisture resistance. It is a block diagram which shows the other structure of a light emitting member. It is a block diagram which shows the structure of the light emitting member which covered the outer surface of the light emission part with the moisture-resistant coating layer. It is a block diagram which shows the structure of the light emitting member which formed the moisture-resistant coating layer in the clearance gap between the inner peripheral surface of a sleeve, and the outer peripheral surface of a cover glass. It is a graph which shows the luminous efficiency of the fluorescent substance of each color with a temperature rise in a conventional structure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram for explaining an embodiment of the present invention. FIG. 1 is a configuration diagram of an endoscope apparatus representing an endoscope and each apparatus to which the endoscope is connected. FIG. 2 is a specific example of the endoscope apparatus. It is an external view which shows a structural example.

  As shown in FIG. 1, the endoscope apparatus 100 includes an endoscope 11, a control device 13, a display unit 15 such as a monitor, and an input unit 17 such as a keyboard and a mouse that input information to the control device 13. It has. The control device 13 includes a light source device 19 and a processor 21 that performs signal processing of a captured image.

  The endoscope 11 includes a main body operation unit 23 and an elongated insertion unit 25 that is connected to the main body operation unit 23 and is inserted into a subject (body cavity). A universal cord 27 is connected to the main body operation unit 23. The distal end of the universal cord 27 is connected to the light source device 19 through a light guide (LG) connector 29A, and is connected to the processor 21 through a video connector 29B.

  As shown in FIG. 2, the main body operation unit 23 of the endoscope 11 has various operation buttons such as buttons for performing suction, air supply, and water supply on the distal end side of the insertion unit 25, and a shutter button at the time of imaging. 31 is also provided, and a pair of angle knobs 33 are provided.

  The insertion portion 25 is composed of a flexible portion 35, a bending portion 37, and a distal end portion (endoscope distal end portion) 39 in order from the main body operation portion 23 disposed on the proximal end side. The bending portion 37 is remotely bent by turning the angle knob 33 of the main body operation portion 23, and thereby the tip portion 39 can be directed in a desired direction.

FIG. 3 shows an external perspective view of the distal end portion of the endoscope.
An observation window 41 of the imaging optical system and illumination windows 43A and 43B of the illumination optical system are disposed at the endoscope distal end portion 39. Illumination light emitted from the pair of illumination windows 43A and 43B arranged with the observation window 41 in between is irradiated to the subject. The reflected light from the subject due to the illuminated illumination light is imaged by the image sensor 45 through the observation window 41 as shown in FIG. The captured observation image is displayed after appropriate image processing is performed on the display unit 15 connected to the processor 21.

  The imaging optical system includes an imaging element 45 such as a CCD (Charge Coupled Device) type image sensor or a CMOS (Complementary Metal Oxide Semiconductor) type image sensor, and an optical member 47 such as a lens for forming an observation image on the imaging element 45. Have The observation image formed and captured on the light receiving surface of the image sensor 45 is converted into an electric signal and input to the image signal processing unit 53 of the processor 21 through the signal cable 51, and is converted into a video signal by the image signal processing unit 53. Is done.

  The processor 21 includes a control unit 63 that performs overall control of each unit, and an imaging signal processing unit 53 that generates a video signal. The control unit 63 performs appropriate image processing on the image data of the observation image output from the imaging signal processing unit 53 and displays the image data on the display unit 15. In addition, a drive signal is output to the laser light source LD1 and the laser light source LD2 of the light source device 19, and a desired amount of illumination light is emitted from each of the illumination windows 43A and 43B. The control unit 63 is connected to a network such as a LAN (not shown) and controls the entire endoscope apparatus 100 such as distributing information including image data.

  The illumination optical system which is an endoscope illumination device includes a light source device 19, a pair of optical fibers 55A and 55B connected to the light source device 19 via a connector 29A, and light emitting ends of the optical fibers 55A and 55B, respectively. The light emitting members 57A and 57B are arranged. The light source device 19 includes a blue light emitting laser light source LD1 that is a semiconductor light emitting element, a red light emitting laser light source LD2, a combiner 61 that combines light emitted from the laser light sources LD1 and LD2, and a combined light. And an optical coupler 62 that demultiplexes and introduces the optical fibers 55A and 55B.

  The laser light source LD1 is a blue-emitting semiconductor laser having a central wavelength of 445 nm, and the laser light source LD2 is a red-emitting semiconductor laser having a central wavelength of 640 nm. As these laser light sources LD1 and LD2, for example, a broad area type InGaN laser diode can be used.

The light emitting members 57A and 57B absorb a part of the blue laser light emitted from the laser light source LD1 and excite and emit green light (for example, Ca ₃ Sc ₂ Si ₃ O ₁₂ , (BaSr) ₂ SiO ₄ , (Sr, Ba) Si ₂ O ₂ N ₂ , α sialon, β sialon, etc.). The spectral characteristics of the emitted light from these light emitting members 57A and 57B are shown in FIG. From the light emitting members 57A and 57B, the blue laser light 65 from the laser light source LD1, the green fluorescence 67 obtained by wavelength-converting the blue laser light 65, and the red laser light 69 from the laser light source LD2 are combined to produce a white color. Light is generated. A dotted line 71 in the figure indicates green to yellow fluorescence of a YAG phosphor that emits light by excitation with the blue laser light 65 for comparison.

Table 1 shows the characteristics of each phosphor. Although the temperature characteristic of the luminous efficiency is relatively low for (BaSr) ₂ SiO ₄ , both the amount of emitted light and moisture resistance are good, and there is no problem in actual use. In the table, ◎ indicates equal or better than YAG phosphor, ○ indicates approximately equal, and Δ indicates inferior.

  The control unit 63 of the processor 21 controls the light amount of the laser light source LD and outputs laser light from the laser light source LD. The output laser light is introduced into each of the optical fibers 55A and 55B and guided to the endoscope distal end portion 39. The laser light guided to the optical fibers 55A and 55B is applied to the light emitting members 57A and 57B, and thereby white illumination light is emitted from the illumination windows 43A and 43B.

  As described above, the light source device of the endoscope apparatus 100 configured as described above uses a phosphor used for white illumination as one kind of green light-emitting phosphor and emits blue laser light, green fluorescence, and red laser light to a predetermined (or White light is obtained by mixing at an arbitrary intensity ratio. Since the red laser light is used as red illumination light, high-efficiency and high-luminance illumination light can be generated without using a red light-emitting phosphor having a relatively low light emission efficiency. Further, since the intensity of red light can be controlled independently of the intensity of blue light, the controllable range of the color tone of illumination light is expanded in the color space, and more delicate color tone adjustment is possible.

  In addition, it is more energy-efficient, energy-saving, and responsive with a desired light intensity when red light is directly generated with a red laser light source than when red light is generated by converting the wavelength of blue laser light with a phosphor. The illumination light can be obtained.

  Further, since there is no red light emitting phosphor having a relatively low light emission efficiency, heat generation of the light emitting member when the light emitting member is irradiated with blue laser light can be suppressed to be small. For example, when α-sialon is used as the phosphor, the heating temperature at the time of laser light irradiation can be reduced from 150 ° C. to about 120 ° C. For this reason, it is not necessary to seal the phosphor with glass having particularly high heat resistance, and a configuration in which the phosphor is sealed with a resin material having a high degree of freedom in processing can be achieved. In particular, a material based on phenylmethylsilicone, which is a heat resistant resin at 150 ° C. or lower, is a material having good sealing properties and also has good light resistance. That is, by using a silicone material having excellent airtightness and watertightness, it is possible to use a phosphor with low moisture resistance, and the degree of freedom in selecting the phosphor material is improved.

  In addition, by sealing the phosphor with a resin material, the structure of the light emitting member disposed at the distal end of the endoscope insertion portion can be greatly changed, and the illumination light with a more uniform intensity distribution can be obtained with high efficiency. . For example, various design changes such as a configuration in which a light emitting area of a light emitting member including a phosphor is enlarged are possible.

Next, a specific configuration example of the light emitting members 57A and 57B will be described.
5A to 5C are schematic configuration diagrams schematically showing the first to third light emitting members, respectively.
<Configuration of first light emitting member>
FIG. 5A shows the first light emitting member 81 </ b> A disposed at the light emitting end of the optical fiber 55. 81 A of 1st light emission members are the light-diffusion part 83 arrange | positioned at the light emission end of the optical fiber 55, the light-emitting part 85 arrange | positioned ahead of the optical path of the light-diffusion part 83, and disperse | distributed green fluorescent substance, and the light emission part And a lens 87 serving as a translucent protective layer covering the light emitting portion 85 in front of the optical path 85. The first light emitting member 81A is fixed to the distal end portion 39 of the endoscope insertion portion.

  In the light emitting unit 85, the light exit surface 89 on the front side of the optical path is formed as an uneven surface having a light scattering effect. The light diffusing portion 83 has a tapered side surface 91 whose diameter increases from the light emitting end 55a of the optical fiber 55 toward the front of the optical path, and is entirely formed in a conical shape. The tapered side surface 91 improves the light utilization efficiency by totally reflecting a part of the light incident on the light diffusion portion 83 from the light emitting end 55a and emitting it toward the front of the optical path.

<Configuration of second light emitting member>
FIG. 5B shows a second light emitting member 81B. In the second light emitting member 81B, the light incident surface 93 on the rear side of the light path of the light emitting portion 85 is formed in a convex shape, and the central portion of the light emitting portion 85 is formed thicker than the peripheral portion. That is, in the cross section perpendicular to the optical path of the light emitting portion 85, the central portion is formed thicker than the peripheral portion that is the peripheral region. Other configurations are the same as those of the first light emitting member 81A.

  According to this configuration, since the central portion of the light emitting unit 85 is formed to be particularly thick, more phosphors can be disposed in a region where the intensity of the light emitted from the light emitting end 55a is high. The emission intensity can be improved. That is, the intensity distribution of the light emitted from the light emitting end 55a is a Gaussian distribution in which the central portion of the light emitting end 55a is maximized. By increasing the thickness of the light emitting portion 85 corresponding to the region of high light intensity in this light intensity distribution, the number of phosphors that contribute to light emission increases. Thereby, the light emission intensity of the whole light emission part 85 increases.

<Configuration of third light emitting member>
FIG. 5C shows a third light emitting member 81C. In the third light emitting member 81C, the light incident surface 95 on the rear side of the light path of the light emitting portion 85 is formed as an uneven surface having a light scattering effect. Other configurations are the same as those of the first light emitting member 81A.

  According to this configuration, since the light incident surface 95 of the light emitting unit 85 has a light scattering effect, when the light from the light emitting end 55a enters the light emitting unit 85 from the light diffusing unit 83, the intensity distribution of the incident light is an average. As a result, the entire light emitting unit 85 emits light uniformly. Thereby, the intensity distribution of the emitted light from the light emitting member 81C can be equalized, and high-quality illumination light without unevenness can be obtained.

<Configuration of Fourth Light-Emitting Member>
FIG. 6A shows a fourth light emitting member 81D. In the fourth light emitting member 81D, the light diffusing portion 83 is made of a translucent resin material, and inside the light diffusing portion 83 made of the translucent resin material, there are micro bubbles made of a material different from the translucent resin material. 97 are mixedly arranged. The microbubble 97 can be a bubble made of a resin material such as silicone resin, acrylic, or polypropylene, or a hollow sphere made of such a resin and the like, and the inside can be constituted by pores of gas, for example, air. Other configurations are the same as those of the first light emitting member 81A.

  According to this configuration, the light incident on the light diffusing unit 83 from the light emitting end 55a is efficiently diffused by the microbubbles 97, and the light emitting unit 85 is irradiated with an even light distribution. For this reason, the light emission intensity distribution in the light emission part 85 becomes more uniform.

<Configuration of fifth light emitting member>
FIG. 6B shows a fifth light emitting member 81E. In the fifth light emitting member 81E, the microbubbles 97 of the fourth light emitting member 81D are arranged such that the arrangement density in the vicinity of the light emitting end 55a of the optical fiber 55 is higher than other peripheral regions.

  According to this configuration, more microbubbles 97 can be arranged in a region where the intensity of light emitted from the light emitting end 55a is high, and the light diffusion effect in the light diffusion portion 83 can be further improved.

<Configuration of sixth light emitting member>
FIG. 6C shows a sixth light emitting member 81F. The sixth light emitting member 81F rotates the microbubbles 97 of the fourth and fifth light emitting members 81D and 87E with the optical axis extending from the light emitting end 55a of the optical fiber 55 toward the front of the optical path as the long axis. An ellipsoidal microbubble 99 is formed. That is, the microbubbles 99 are aligned so as to be longer than the light traveling direction. In addition, the above-described microbubbles 97 are also arranged in the light emitting unit 85. As a result, the scattering efficiency is increased at a portion having a high light intensity distribution close to the light incident side, and light transmission loss can be reduced.

  The spheroid microbubbles 99 can be formed in a process in which the spheroid microbubbles 99 are formed in a shape close to a true sphere, and then heated and compressed to be crushed and mixed into the sealing resin.

  According to this configuration, by using the microbubbles 99 as spheroids, the light incident on the microbubbles 99 can be prevented from being scattered backward in the optical path, and the light utilization efficiency can be improved. In addition, by arranging the microbubbles 97 in the light emitting unit 85, the light diffusion effect in the light emitting unit 85 is improved, and the light emission intensity distribution in the light emitting unit 85 becomes more uniform.

  By arranging the microbubbles 97 in the light emitting unit 85, the density of the phosphor can be adjusted, and the scattering property of the fluorescence generated by the phosphor can be improved. In addition to the silicone resin, the microbubbles 97 can adjust the strength of the light emitting portion 85 by using quartz glass beads, and the temperature stability can be improved by using iron oxide. Moreover, if silicon nitride is used, thermal conductivity will improve, and if diatomaceous earth is used, the hardness of the light emission part 85 can be adjusted.

<Configuration of seventh light emitting member>
FIG. 7 shows a seventh light emitting member 81G. The seventh light emitting member 81G transmits blue laser light serving as excitation light of the phosphor between the light emitting end 55a of the optical fiber 55 and the light diffusion portion 83, and reflects green fluorescence emitted from the phosphor. A fluorescent reflecting film 101 is provided. The light diffusing portion 83, the light emitting portion 85, and the lens 87 of the light emitting member 81G are the same as the sixth light emitting member 81F in the illustrated example, but may be other light emitting members 81A to 81E.

The fluorescent reflecting film 101 is formed by, for example, sputtering a TiO ₂ film with an appropriate thickness (for example, film thickness t = 0.84 × refractive index × design wavelength (550 nm)) on the emission end face of the optical fiber 55. Form with. One characteristic example of the transmittance and reflectance of the thin film thus produced is shown in FIG. According to this characteristic, the reflectance in the visible wavelength range can be increased with respect to the reflectance near 450 nm.

  According to this configuration, it is possible to prevent the fluorescence from the light emitting portion from returning to the light source side through the optical fiber 55 by the fluorescent reflection film 101, and to improve the light utilization efficiency.

<Configuration of eighth light emitting member>
FIG. 9 shows an eighth light emitting member 81H. The eighth light emitting member 81H is provided with a light-transmitting inorganic material layer 103 such as glass or sapphire instead of the lens 87 of the light emitting members 81A to 81G. In addition, the metal reflection film 105 that reflects blue laser light, red laser light, and fluorescence emitted from the phosphor on the outer peripheral surface (conical side surface) from the light emitting end 55 a of the optical fiber 55 in the light diffusion portion 83 to the light emitting portion 85. Is provided. Other configurations are the same as the configuration of the seventh light emitting member 81G (or the light emitting members 81A to 81F).

  The translucent inorganic material layer 103 may be a plate-like cover in addition to the lens-like shape that diffuses the emitted light as illustrated. This translucent inorganic material layer 103 is fixed by a translucent resin layer 107 immediately above the light emitting portion 85.

  According to this configuration, the translucent inorganic material layer 103 is disposed on the light emitting surface of the light emitting member 81H, thereby improving chemical resistance and friction resistance during endoscope cleaning and further improving the durability of the light emitting member. Can be increased. Further, by providing the metal reflection film 105 on the outer peripheral surface of the light diffusion portion 83, the light use efficiency is improved and the emitted light intensity can be increased. Further, the metal reflection film 105 prevents external light from entering from the outer peripheral surface of the light diffusion portion 83.

<Configuration of ninth light emitting member>
FIG. 10 shows a ninth light emitting member 81I. The ninth light emitting member 81I can be configured in the same manner as the light emitting members 81A to 81G except that the shape of the light emitting end 55a of the optical fiber 55 is changed. The optical fiber 55 is a single mode or multimode optical fiber having a core portion 109 at the center of the fiber and a clad portion 111 covering the outer periphery of the core portion 109, and a light emitting end 55 a is inserted into the light diffusion portion 83. ing. Further, at the light emitting end 55a, the core portion 109 is projected outward from the clad portion 111.

  According to this configuration, the light guided by the optical fiber 55 is emitted from the core portion 109 protruding outward in the axial direction of the light emitting end 55 a and diffused in the light diffusion portion 83. In the light emitting member described above, the light emitting end of the optical fiber 55 is configured with a cross section perpendicular to the axis. However, in this configuration, the core portion 109 that substantially contributes to the light guide has a predetermined length from the cladding portion 111. By projecting, the exposed area of the core part 109 increases. For this reason, the light emission area of the core part 109 increases and light diffusibility can be improved more. Further, the protruding core portion 109 is disposed inside the light diffusing portion 83, so that the guided light can be introduced into the light diffusing portion 83 without leakage. Further, by dispersing and arranging the phosphors in the light diffusion portion 83, high intensity fluorescence can be obtained in combination with the fluorescence from the light emitting portion 85.

  In order to protrude the core part 109 from the clad part 111, for example, a method of immersing the tip of the optical fiber in a solution such as hydrofluoric acid and dissolving so that the clad part 111 is exposed, and the tip of the optical fiber is conical. For example, a cutting method can be used.

<Configuration of 10th light emitting member>
FIG. 11 shows a tenth light emitting member 81J. The tenth light emitting member 81J is a light diffusing portion 83A in which the light diffusing portion 83 of the first light emitting member 81A shown in FIG. 5 is formed in a plate shape, and the optical fiber 55 is located at the center of the surface opposite to the light emitting portion 53. The light emitting end 55a is connected. In addition, a metal reflection film 105 that reflects blue laser light, red laser light, and fluorescence emitted from the phosphor is provided on the back surface and side surfaces of the light diffusion portion 83A excluding the connection surface with the light emitting end 55a of the optical fiber 55. ing. In the illustrated example, the light diffusion portion 83A is shown as a translucent resin material as described above, but may be an air layer.

  According to this configuration, the thickness of the light emitting member 81J can be reduced, and a more compact configuration can be achieved. Therefore, the degree of freedom of arrangement of the light emitting member 81J on the endoscope is improved, which can contribute to the downsizing of the endoscope insertion portion.

<Other structural examples of light emitting member>
Next, another configuration example of the light emitting member will be described.
FIG. 12 is an explanatory diagram showing the characteristics of the resin material for encapsulating the phosphor, and is a graph showing the relationship between light durability and moisture resistance. In general, a resin material such as silicone having good moisture resistance (material in the region A1) has poor heat resistance and is not suitable as a phosphor sealing material. Further, since the light durability is low, it can be applied only to portions other than the optical path such as the lens peripheral portion, and the use range is limited.

  Therefore, as described above, a red phosphor is eliminated, a green phosphor having high luminous efficiency is used, and a temperature rise at the time of laser irradiation is suppressed, whereby a resin material (material in region A2) based on phenylmethyl silicone is used. ) Can be used as a phosphor sealing material. Phenylmethyl silicone has a heat resistance of about 150 ° C., is a material having a good balance between moisture resistance and light durability and good sealing properties.

  By sealing the phosphor with such a resin material with improved light durability, the light durability of the light emitting portion is improved. However, if the material of the region A3 is used to further improve the light durability, a decrease in moisture resistance cannot be ignored. Inside the endoscope, in addition to intrusion of water from the outside, condensation may occur due to air supply / water supply, etc., and moisture resistance is required.

  Therefore, in this configuration, the resin material for sealing the phosphor is made of a material having high light durability, and the moisture resistance of the entire light emitting unit is improved by another member. That is, the functions of light durability and moisture resistance are realized by separate members.

FIG. 13 shows a configuration diagram of the light emitting member of this configuration.
The light emitting member 121 is disposed facing the light emitting end of the optical fiber 55 and has a light emitting portion 85 in which green phosphors are dispersedly arranged, and a cover glass serving as a translucent protective layer disposed in front of the light path of the light emitting portion 85. 123 and a sleeve 125 that covers the outer periphery of the light emitting portion 85 and the cover glass 123 and supports both of them on the inner peripheral surface. One end side of the sleeve 125 is fixed to the distal end portion of the endoscope insertion portion, and the other end side (not shown) opposite to the light emitting side has a water-tight / air-tight structure inside the sleeve 125.

  The light emitting unit 85 has a configuration in which phosphors that emit green fluorescent light similar to those described above are mixedly disposed in a resin such as methyl silicon belonging to the region A3 shown in FIG. 12, particularly gel-like methyl silicon. When sealing the phosphor with this resin, it is preferable to mix quartz glass beads or diatomaceous earth with the resin in order to make the outer surface of the light emitting portion 85 less susceptible to damage by external force. By mixing the phosphor with quartz glass or the like, it is possible to prevent deviation due to aggregation or partial sedimentation of the phosphor and to emit light uniformly.

  Properties required for the resin material for encapsulating the phosphor include hardness, refractive index (light extraction efficiency), transparency in the wavelength range to be used, temperature / humidity / light durability, gas permeability, and the like. These characteristics can be set in a favorable range by using the above resin.

  The cover glass 123 is arranged so that the light emission surface 123a thereof and the light emission side end surface 125a of the sleeve 125 are on the same surface. A moisture resistant coating layer 127 for improving moisture resistance is formed on the light emitting surface 123a of the cover glass 123 in a range including at least an annular region from the outer peripheral edge of the light emitting surface 123a to the inner peripheral edge of the sleeve 125. Has been.

  The moisture resistant coating layer 127 is made of a ceramic coating material having high moisture resistance and water repellency, and reliably prevents moisture from entering from the interface between the cover glass 123 and the sleeve 125.

  According to this configuration, even if a resin material having low moisture resistance is used as the resin material for sealing the phosphor of the light emitting unit 85, moisture entry is prevented by the moisture resistant coating layer 127, and the light emitting unit 85 is placed in the sleeve 125. It can be kept watertight and airtight. Therefore, while maintaining high watertightness and airtightness, the phosphor is sealed with a resin material having higher light durability than the resin material based on phenylmethylsilicone, and the light durability of the entire light emitting unit 85 is improved. It can be improved.

  As shown in FIG. 14, the moisture-resistant coating layer 127 is provided on the light emitting side end surface 125a of the sleeve 125 and the light emitting surface 123a of the cover glass 123 as shown in FIG. The surface may be covered with a moisture-resistant coating layer 127A. In this case, a more reliable moisture-proof effect can be obtained for the light emitting unit 85.

  Further, as shown in FIG. 15, a moisture-resistant coating layer 127 </ b> B may be formed in a gap between the inner peripheral surface of the sleeve 125 and the outer peripheral surface of the cover glass 123. In this case, since the entire outer peripheral surface of the cover glass 123 serving as a moisture passage is sealed with the moisture-resistant coating layer 127B, it is possible to more reliably prevent moisture from entering.

  The moisture resistant coating layer 127 can be applied not only to the illumination window as described above but also to an observation window for obtaining an observation image. In that case, the good water repellency can prevent the observation image from being affected by liquid suitability.

  The coating layer is composed of a coating layer of an alkoxysilane and a mixture, and more specifically, a layer containing a hydrolysis product of an alkoxy metal salt and a dispersion of metal fine particles or metal oxide fine particles (for example, Japanese Patent Laid-Open 10-279885).

  The coating agent with an alkoxy metal salt is an alcoholic hydrolysis / condensation type coating agent, and forms a glassy layer having hydrophobicity and shielding properties. This coating layer has high hardness and excellent properties such as heat resistance, water repellency, chemical resistance and corrosion resistance. For this reason, as described above, by providing the coating film, moisture resistance (sealing performance) is enhanced, and intrusion of moisture is prevented. Further, even when the coating layer is baked, there is no generation of inappropriate gas that affects the silver reflecting film.

  Examples of the alkoxysilane include the following materials. Tetramethoxysilane, tetraethoxysilane, condensate of tetramethoxysilane (for example, methyl silicate 51), condensate of tetraethoxysilane (for example, methyl silicate 40), methyltrimethoxysilane, phenyltrimethoxysilane, 3-glycidoxypropyl Trimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane.

As the material of the coating layer using the alkoxy metal salt, the following materials can be used, and specific effects can be obtained respectively.
(A) Alkoxy metal salt and mixture (inorganic)
(1) SiO ₂ alone: lustrous, high hardness, excellent in water repellency, insulation, and rubbing durability.
(2) SiO ₂ + alumina (Al ₂ O ₃ ) filler mixture: lustrous, fine, anti-contamination, heat resistance (expansion), and excellent illumination light scattering.
(3) SiO ₂ + TiO ₂ (with + alumina): Improved light resistance and excellent antibacterial and heat resistance.
(4) Further, Ag is added ... has deodorizing, antibacterial and antifungal effects, and is excellent in infrared radiation (heat dissipation) and corrosion resistance.
(5) Further, zirconia (ZrO ₃ ) is added ... High purity and high hardness can be obtained, and high heat resistance and antioxidant effect can be obtained.
(6) In addition, iron oxide is added ... High hardness and excellent infrared radiation (heat dissipation) properties.
(7) CeO ₂ ... Has an ultraviolet absorption effect. For example, when excited with ultraviolet rays, it absorbs ultraviolet rays radiated without wavelength conversion.
(8) Magnesium oxide: Excellent adhesion.
(9) Cu, copper oxide: Excellent heat dissipation, antibacterial, and deodorizing effects.
(10) Aluminum (11) Titanium (12) Ceramics such as silicon, boron, boron nitride BN, cyan CN

(B) Alkoxy metal salt and mixture (inorganic and organic)
(1) Acrylic: improves adhesion when the substrate is rough (but peels off when formed thick)
(2) Butyral: It can be suitably applied to a metal with a rough base.
(3) Fluorine (4) Silicone or modified silicone: Adhesiveness to metal, resin, glass is improved.

  As described above, the present invention is not limited to the above-described embodiments, and those skilled in the art can make changes and applications based on combinations of the configurations of the embodiments, descriptions in the specification, and well-known techniques. This is also the scope of the present invention, and is included in the scope for which protection is sought.

As described above, the following items are disclosed in this specification.
(1) An endoscope illumination device that irradiates illumination light toward an object from an illumination window provided at a distal end of an endoscope insertion portion,
A blue semiconductor light source that generates blue light;
A red semiconductor light source that generates red light; and
A light guide member for guiding blue light from the blue semiconductor light source and red light from the red semiconductor light source;
A light emitting member disposed facing the light exit end of the light guide member inside the illumination window;
With
The light emitting member includes a green phosphor that transmits the red light substantially without absorbing it, absorbs part of the blue light as excitation light, emits green-based fluorescence, and transmits the remaining part. Consists of
An endoscope illumination device in which the green phosphor is sealed with a resin material in the light emitting member.
According to this endoscope illumination device, since red light is generated by red laser light, high-efficiency and high-luminance illumination light can be generated without using a red-emitting phosphor having a relatively low emission efficiency. Further, since the intensity of red light can be controlled independently of the intensity of blue light, the controllable range of the color tone of illumination light is expanded in the color space, and more delicate color tone adjustment is possible. By sealing the phosphor with a resin material, the structure of the light emitting member disposed at the distal end of the endoscope insertion portion can be greatly changed, and the illumination light with a more uniform intensity distribution can be obtained with high efficiency. .

(2) The endoscope illumination device according to (1),
An endoscope illumination device in which the light guide member is made of an optical fiber.
According to this endoscope illumination device, the laser light is guided to the illumination window at the distal end of the endoscope insertion portion through the endoscope insertion portion by means of a thin optical fiber. It can contribute to diameter.

(3) The endoscope illumination device according to (1) or (2),
The light emitting member includes a light diffusing portion disposed at a light emitting end of the light guide member, and a light emitting portion disposed in front of the light path of the light diffusing portion and in which the green phosphors are dispersedly disposed. Endoscope illumination device.
According to this endoscope illuminating device, the light emitted from the light guide member is dispersed by the light diffusing unit and is uniformly irradiated over a wide area in the light emitting unit. For this reason, fluorescence with uniform intensity can be extracted from the light emitting portion.

(4) The endoscope illumination device according to (3),
An endoscope illumination device in which an optical path front side of the light emitting unit is formed with an uneven surface having a light scattering effect.
According to this endoscope illuminating device, by forming the front side of the light path of the light emitting portion with a concavo-convex surface, the light emitting area of the light emitting portion can be increased and the emitting direction of the emitted light can be made random, and the intensity unevenness is small. Illumination light is obtained.

(5) The endoscope illumination device according to (3) or (4),
An endoscope illumination device in which a central part is formed thicker than a peripheral part in a vertical cross section of the light emitting part with respect to the optical path.
According to this endoscope illuminating device, a larger amount of phosphor can be arranged in a region where the intensity of emitted light from the light emitting end of the light guide member is high. For this reason, the emitted light intensity of a light emission part can be improved.

(6) The endoscope illumination device according to any one of (3) to (5),
An endoscope illumination device in which an optical path rear side of the light emitting unit is formed with an uneven surface having a light scattering effect.
According to this endoscope illumination device, when light from the light exit end of the light guide member enters the light emitting portion from the light diffusing portion, the intensity distribution of the incident light is averaged to make the entire light emitting portion uniform. Can emit light. Thereby, the intensity distribution of the emitted light from the light emitting member can be equalized, and high-quality illumination light without unevenness can be obtained.

(7) The endoscope illumination device according to any one of (3) to (6),
An endoscope illumination apparatus in which the light diffusing portion is made of a translucent resin material, and microbubbles made of a material different from the translucent resin material are mixedly arranged inside the light diffusing portion.
According to this endoscope illuminating device, light incident on the light diffusing portion from the exit end of the light guide member is reflected and refracted by the microbubbles, and is efficiently diffused. For this reason, it becomes a uniform light distribution and is irradiated to the light emitting part, and the light emission intensity distribution in the light emitting part becomes more uniform.

(8) The endoscope illumination device according to (7),
Endoscopic illumination device in which the microbubbles of the light diffusing unit are arranged in the vicinity of the light emitting end of the light guide member at a higher density than other regions.
According to this endoscope illumination device, light emitted from the light exit end of the light guide member is efficiently diffused by the microbubbles, and the light diffusion effect in the light diffusion portion is further improved.

(9) The endoscope illumination device according to (7) or (8),
The endoscope illumination device, wherein the microbubble is a spheroid whose major axis is an optical axis extending toward the front of the optical path starting from the light emitting end of the light guide member.
According to this endoscope illumination device, the light incident on the microbubbles can be reduced from being scattered to the rear of the optical path, and the light utilization efficiency can be improved.

(10) The endoscope illumination device according to any one of (7) to (9),
An endoscope illumination device in which the microbubbles are mixedly disposed in the light emitting unit.
According to this endoscope illumination device, by providing microbubbles in the light emitting part, the density of the phosphor in the light emitter can be adjusted, and the scattering property of the fluorescence generated by the phosphor can be improved.

(11) The endoscope illumination device according to any one of (3) to (10),
Endoscopic illumination device provided with a fluorescent reflection film that transmits the blue light and the red light and reflects the fluorescence emitted by the phosphor between the light emitting end of the light guide member and the light diffusion portion .
According to this endoscope illuminating device, it is possible to prevent the fluorescence from the light emitting portion from returning to the light source side through the optical fiber by the fluorescent reflection film, and the light source can always be kept in a stable state. Moreover, light utilization efficiency can be improved by using fluorescence without waste.

(12) The endoscope illumination device according to any one of (3) to (11),
An endoscope illuminating device in which a metal reflection film is provided on an outer peripheral surface from a light emitting end of the light guide member to the light emitting portion in the light diffusing member.
According to this endoscope illuminating device, reflection is repeated in the light diffusing member by the metal reflecting film, and the light component toward the front of the optical path can be increased, so that the light use efficiency can be improved. Moreover, it can prevent that external light enters from the outer peripheral surface of a light-diffusion member.

(13) The endoscope illumination device according to (12),
An endoscope illumination device in which the metal reflection film is configured to contain silver.
According to the endoscope illumination device, light loss can be suppressed by using high-reflectance silver as a reflective film.

(14) The endoscope illumination device according to any one of (3) to (13),
The green phosphor is dispersedly disposed in the light diffusion portion;
An endoscope illumination device in which a light emitting end of the light guide member is inserted into the light diffusion portion.
According to this endoscope illumination device, the light output end of the light guide member is arranged inside the light diffusion portion, so that the light diffusion portion can be irradiated without leakage. Further, since the green phosphor is dispersedly arranged in the light diffusion portion, the total amount of the green phosphor can be substantially increased, and higher intensity fluorescence can be obtained from the light diffusion portion and the light emitting portion.

(15) The endoscope illumination device according to (14),
An endoscope illumination device in which the light emitting end of the light guide member is formed such that a core portion of an optical fiber protrudes axially outward from a cladding portion.
According to this endoscope illumination device, light guided through the light guide member from the core portion protruding outward in the axial direction is emitted from the entire exposed core portion, and the light diffusion effect is enhanced.

(16) The endoscope illumination device according to any one of (3) to (15),
An endoscope illumination device having a light-transmitting inorganic material layer covering the light emitting unit in front of the light path of the light emitting unit.
According to the endoscope illumination device, the chemical resistance during endoscope cleaning can be further improved by covering the light emitting portion with the light-transmitting inorganic material layer.

(17) The endoscope illumination device according to (16),
An endoscope illumination device in which the light-transmitting inorganic material layer is made of glass or sapphire.
According to the endoscope illumination device, it is possible to improve the friction resistance and the durability of the light emitting member.

(18) An endoscope apparatus including the endoscope illumination device according to any one of (1) to (17).
According to this endoscope apparatus, the structure of the light emitting member disposed at the distal end of the endoscope insertion portion can be greatly changed, and illumination light with a more uniform intensity distribution can be obtained with high efficiency.

(19) The endoscope apparatus according to (18),
At the tip of the endoscope insertion portion, the illumination window and an opening for accommodating the illumination window are disposed,
An endoscope apparatus in which a moisture-resistant coating layer is formed in a range including at least an annular region between an outer peripheral edge of the illumination window and an inner peripheral edge of the opening on the light emission surface of the illumination window.
According to this endoscope apparatus, the moisture-resistant coating layer is formed in the annular region between the illumination window and the opening on the light emission surface of the illumination window, so that moisture can be reliably prevented from entering from the annular region. Can be prevented.

(20) The endoscope device according to (18),
An endoscope apparatus in which an outer surface of the light emitting unit is covered with a moisture-resistant coating layer.
According to this endoscope apparatus, since the light emitting part is covered with the moisture-resistant coating layer, it is possible to reliably prevent moisture from entering the light emitting part.

(21) The endoscope apparatus according to (18),
At the tip of the endoscope insertion portion, the illumination window and an opening having an inner peripheral surface joined to the outer peripheral surface of the illumination window are arranged,
An endoscope apparatus in which a moisture-resistant coating layer is formed between an outer peripheral surface of the illumination window and an inner peripheral surface of the opening.
According to this endoscope apparatus, since the outer peripheral surface of the illumination window serving as a moisture passage and the inner peripheral surface of the opening are sealed with the moisture-resistant coating layer, it is possible to prevent moisture from entering more reliably.

(22) The endoscope apparatus according to any one of (18) to (21),
An endoscope apparatus in which the moisture resistant coating layer has a composition containing a hydrolyzed product of an alkoxy metal salt, a dispersion of metal fine particles or metal oxide fine particles.
According to this endoscope apparatus, it is possible to reliably prevent moisture from entering with a material having good water repellency.

DESCRIPTION OF SYMBOLS 11 Endoscope 19 Light source device 25 Insertion part 39 Front-end | tip part (endoscope front-end | tip part)
43A, 43B Illumination window 47 Optical member 55, 55A, 55B Optical fiber 55a Light emitting end 57A, 57B Light emitting member 65 Blue laser light 67 Green fluorescence 69 Red laser light 81, 81A, 81B, 81C, 81D, 81E, 81F, 81G, 81H, 81I, 81J Light emitting member 83, 83A Light diffusing portion 85 Light emitting portion 87 Lens 89 Light exit surface 91 Tapered side surface 93 Light incident surface 95 Light incident surface 97 Micro bubble 99 Micro bubble 100 Endoscope device 101 Fluorescent reflection film DESCRIPTION OF SYMBOLS 103 Inorganic glass 105 Metal reflecting film 107 Translucent resin layer 109 Core part 111 Cladding part 121 Light emitting member 123 Cover glass 125 Sleeve 125a Light emission side end surface 127, 127A, 127B Moisture resistant coating layer LD1 Blue laser light source LD2 Red laser light source

Claims (22)

An endoscope illumination device that irradiates illumination light toward an object from an illumination window provided at a distal end of an endoscope insertion portion,
A blue semiconductor light source that generates blue light;
A red semiconductor light source that generates red light; and
A light guide member for guiding blue light from the blue semiconductor light source and red light from the red semiconductor light source;
A light emitting member disposed facing the light exit end of the light guide member inside the illumination window;
With
The light emitting member includes a green phosphor that transmits the red light substantially without absorbing it, absorbs part of the blue light as excitation light, emits green-based fluorescence, and transmits the remaining part. Consists of
An endoscope illumination device in which the green phosphor is sealed with a resin material in the light emitting member. The endoscope illumination device according to claim 1,
An endoscope illumination device in which the light guide member is made of an optical fiber. An endoscope illumination device according to claim 1 or claim 2,
The light emitting member includes a light diffusing portion disposed at a light emitting end of the light guide member, and a light emitting portion disposed in front of the light path of the light diffusing portion and in which the green phosphors are dispersedly disposed. Endoscope illumination device. An endoscope illumination device according to claim 3,
An endoscope illumination device in which an optical path front side of the light emitting unit is formed with an uneven surface having a light scattering effect. An endoscope illumination device according to claim 3 or claim 4,
An endoscope illumination device in which a central part is formed thicker than a peripheral part in a vertical cross section of the light emitting part with respect to the optical path. An endoscope illumination device according to any one of claims 3 to 5,
An endoscope illumination device in which an optical path rear side of the light emitting unit is formed with an uneven surface having a light scattering effect. An endoscope illumination device according to any one of claims 3 to 6,
An endoscope illumination device in which the light diffusing portion is made of a translucent resin material, and microbubbles made of a material different from the translucent resin material are mixedly arranged inside the light diffusing portion. The endoscope illumination device according to claim 7,
Endoscopic illumination device in which the microbubbles of the light diffusing unit are arranged in the vicinity of the light emitting end of the light guide member at a higher density than other regions. An endoscope illumination device according to claim 7 or 8,
The endoscope illumination device, wherein the microbubble is a spheroid whose major axis is an optical axis extending toward the front of the optical path starting from the light emitting end of the light guide member. It is an illuminating device for endoscopes as described in any one of Claims 7-9,
An endoscope illumination device in which the microbubbles are mixedly disposed in the light emitting unit. An endoscope illumination device according to any one of claims 3 to 10,
Endoscopic illumination device provided with a fluorescent reflection film that transmits the blue light and the red light and reflects the fluorescence emitted by the phosphor between the light emitting end of the light guide member and the light diffusion portion . An endoscope illumination device according to any one of claims 3 to 11,
An endoscope illuminating device in which a metal reflection film is provided on an outer peripheral surface from a light emitting end of the light guide member to the light emitting portion in the light diffusing member. An endoscope illumination device according to claim 12,
An endoscope illumination device in which the metal reflection film is configured to contain silver. An endoscope illumination device according to any one of claims 3 to 13,
The green phosphor is dispersedly disposed in the light diffusion portion;
An endoscope illumination device in which a light emitting end of the light guide member is inserted into the light diffusion portion. The endoscope illumination device according to claim 14,
An endoscope illumination device in which a light emitting end of the light guide member is formed such that a core portion of an optical fiber protrudes outward from a clad portion. An endoscope illumination device according to any one of claims 3 to 15,
An endoscope illumination device having a light-transmitting inorganic material layer covering the light emitting unit in front of the light path of the light emitting unit. The endoscope illumination device according to claim 16,
An endoscope illumination device in which the light-transmitting inorganic material layer is made of glass or sapphire.   An endoscope apparatus equipped with the endoscope illumination apparatus according to any one of claims 1 to 17. The endoscope apparatus according to claim 18, wherein
At the tip of the endoscope insertion portion, the illumination window and an opening for accommodating the illumination window are disposed,
An endoscope apparatus in which a moisture-resistant coating layer is formed in a range including at least an annular region between an outer peripheral edge of the illumination window and an inner peripheral edge of the opening on the light emission surface of the illumination window. The endoscope apparatus according to claim 18, wherein
An endoscope apparatus in which an outer surface of the light emitting unit is covered with a moisture-resistant coating layer. The endoscope apparatus according to claim 18, wherein
At the tip of the endoscope insertion portion, the illumination window and an opening having an inner peripheral surface joined to the outer peripheral surface of the illumination window are arranged,
An endoscope apparatus in which a moisture-resistant coating layer is formed between an outer peripheral surface of the illumination window and an inner peripheral surface of the opening. The endoscope apparatus according to any one of claims 18 to 21,
An endoscope apparatus in which the moisture resistant coating layer has a composition containing a hydrolyzed product of an alkoxy metal salt, a dispersion of metal fine particles or metal oxide fine particles.

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