JP2005152131A - Endoscope apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably present correct information required for diagnosis by raising a red color rendering property. <P>SOLUTION: The optical system 1 of an endoscope apparatus includes: an LED 2 for emitting white light; a light converging element 3 for converging light emitted from the LED 2; and a light guide 4 for transmitting light, which is converged by the light converging element 3, from one end and irradiating it from the other end. The light emitted from the LED 2 is irradiated through a light path including the light converging element 3 and the light guide 4. A transparent solid fluorescent element 5 containing a fluorescent material is arranged in the light path. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an endoscope apparatus capable of emitting illumination light rich in red component and having high color rendering properties.

  In recent years, the use of a white light emitting diode (white LED) as a light source of an endoscope apparatus has attracted attention. For white LED, LED element emitting blue light and phosphor emitting yellow light are combined to obtain white, LED element emitting ultraviolet light and three types of phosphor emitting red, green and blue light It is known to obtain a white color by combining.

  By the way, in diagnosing a disease by an endoscope apparatus, it is important to be able to recognize a subtle color difference of a lesion occurring in an organ. Therefore, the spectral distribution of the illumination light emitted from the endoscope apparatus has an important meaning.

   Thus, for example, the light spectrum of a white LED that combines a blue LED element and a yellow phosphor is shown in FIG. FIG. 4 is a characteristic diagram showing the light spectrum of a white LED in which a blue LED element and a yellow phosphor are combined. The horizontal axis represents wavelength [nm] and the vertical axis represents relative wavelength. The luminescence intensity is shown respectively.

That is, as shown in FIG. 4, the light spectrum of the white LED that combines the blue LED element and the yellow phosphor emits a component in the wavelength range of 650 [nm] to 750 [nm] deep red. It is known that the distribution is small.
On the other hand, endoscope apparatuses using LEDs have been conventionally proposed. In this conventional endoscope apparatus, an optical amplification type optical fiber made of a plastic material mixed with a fluorescent dye is used as a light guide, and excitation light from a semiconductor laser element is incident on the light guide so that the phosphor in the light guide is used. At the same time as emitting light, a configuration is adopted in which illumination light is incident on the light guide from the light emitting LED (Patent Document 1: Japanese Patent Laid-Open No. 7-159701).

The conventional endoscope apparatus and the other conventional endoscope apparatuses both include a semiconductor light emitting element that emits white light, a light collecting element that collects light emitted from the semiconductor light emitting element, and the light collecting element. A light guide that transmits the light condensed by the element from one end and irradiates from the other end, and the light emitted from the semiconductor light emitting element is irradiated through an optical path including the light collecting element and the light guide. Have.
JP 7-159701 A

When a white LED that combines the LED element emitting blue light and a phosphor emitting yellow light is used in an endoscope apparatus, since the component of the deep red region is small as described above, the inside of the body is observed with this irradiation light. However, since the red portion has a poor color rendering property, there is a problem in that the subtle difference in red of the lesion and the distinction between arteries and veins are not clearly displayed and information for correct diagnosis cannot be provided.
On the other hand, in the conventional endoscope apparatus, there is no description about the color rendering property of red, and there is a possibility that information for correct diagnosis cannot be provided. Since two types of light sources, ie, semiconductor lasers that excite the excitation light, are required for the amplification type optical fiber phosphor, the number of parts is increased, the device configuration becomes complicated, and the device price is expensive. .

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an endoscope apparatus capable of improving the color rendering property of red and reliably presenting accurate information necessary for diagnosis. .

An endoscope apparatus according to the invention of claim 1 is a semiconductor light emitting element that emits white light, a light collecting element that collects light emitted from the semiconductor light emitting element, and the light collected by the light collecting element. An endoscope apparatus comprising a light guide that transmits light from one end and that emits light from the other end, and that emits light emitted from the semiconductor light emitting element through an optical path including the light collecting element and the light guide In
A transparent solid fluorescent element containing a phosphor is disposed in the optical path.

  According to a second aspect of the present invention, in the endoscope apparatus according to the first aspect, the solid-state fluorescent element has a light emission peak in a deep red region having a wavelength of 650 [nm] to 750 [nm]. It is.

  According to a third aspect of the present invention, in the endoscope apparatus according to the first aspect, the solid fluorescent element is disposed between the light condensing element and one end of the light guide.

  According to a fourth aspect of the present invention, in the endoscope apparatus according to the first aspect, the solid-state fluorescent element is arranged on the other end irradiation side of the light guide.

  According to the present invention, there is an effect that the color rendering property of red can be improved and accurate information necessary for diagnosis can be reliably presented.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 relate to a first embodiment of the present invention, FIG. 1 is a diagram showing a configuration of a main part of an optical system of an endoscope apparatus, and FIG. 2 is a characteristic for explaining an optical spectrum of the optical system of FIG. FIG.

  As shown in FIG. 1, the optical system 1 of the endoscope apparatus according to the present embodiment includes an LED 2 that emits white light, a condensing element 3 that condenses the light emitted from the LED 2, and the condensing element. And a light guide 4 for transmitting the light condensed at 3 from one end and irradiating from the other end. The light emitted from the LED 2 is irradiated through an optical path including the light collecting element 3 and the light guide 4. In addition, a transparent solid fluorescent element 5 containing a phosphor is disposed in the optical path.

  Further, in the optical system 1 of the endoscope apparatus, the solid fluorescent element 3 having a performance having a light emission peak in a deep red region with a wavelength of 650 [nm] to 750 [nm] is employed. In addition, the solid fluorescent element 3 is arranged between the light condensing element 3 and one end of the light guide 4.

  More specifically, the LED 2 is a combination of an LED element that emits blue light and a phosphor that emits yellow light, and emits white light by combining blue and yellow. The LED 2 is connected to the LED drive circuit 6. The LED drive circuit 6 can supply current to the LED 2 by a control signal from a control circuit (not shown).

  The fluorescent solid-state element 5 is a fluorescent light composed of an oxide to which rare earth ions having a light emission peak in the deep red region having a wavelength of 650 [nm] to 750 [nm] are excited by a blue component of light emitted from the LED 2. It is a transparent resin material containing a dispersed body. The fluorescent solid element 5 has a truncated cone shape and has a small circular surface 5a, a side wall surface 5b, and a bottom surface 5c. The frustoconical fluorescent solid element 5 is disposed with the small circular surface 5 a facing the LED 2 and the bottom surface 5 c facing the one end 4 a of the light guide 4. The frustoconical fluorescent solid element 5 has a reflective film 7 deposited on the side wall surface 5 b, and the light guide 4 is reflected by the reflective film 7 when the fluorescence of the deep red light is generated inside the fluorescent solid element 5. It can be reflected to the side.

  The operation of the optical system 1 of the endoscope apparatus of the present embodiment having such a configuration will be described. FIG. 2 is a characteristic diagram for explaining the optical spectrum of the optical system employed in the endoscope apparatus of the present embodiment for carrying out the present invention. In the characteristics shown in FIG. 2, the horizontal axis represents wavelength [nm], and the vertical axis represents relative emission intensity.

  When a current is supplied from the LED drive circuit 6, the LED 2 emits white light. The emitted light is collected by the condenser lens 3 and enters the fluorescent solid element 5.

  The fluorescent solid element 5 is excited by the blue component of the light incident from the LED 2 and generates light in the deep red region having a wavelength of 650 to 750 [nm]. The light incident on the fluorescent solid-state element 5 and the deep red light generated therein are combined and transmitted through the inside of the light guide 5 and irradiated from the irradiation terminal of the light guide 5 to observe an observation object (not shown). Illuminate.

  As shown in FIG. 2, in the spectrum of the illuminated light, the intensity of the blue light near 470 [nm] is reduced, but the red illumination light having a peak near 710 [nm] and high color rendering properties. Can be obtained. The reason why the intensity of blue light near 470 [nm] is reduced is that blue light is absorbed by the phosphor.

  According to the endoscope apparatus configured as described above, illumination light having a rich color rendering property of a red component in which the white color emitted from the LED 2 and the deep red color emitted from the phosphor are combined is irradiated. It is possible to present accurate information necessary for diagnosing a lesion.

  Further, according to the endoscope apparatus configured as described above, the phosphor is excited by the light emitted from one white LED and also serves as the illumination light, so that the number of components is small and the structure is simple and inexpensive. Can be obtained.

  FIG. 3 is a diagram illustrating a main configuration of the optical system of the endoscope apparatus according to the second embodiment of the present invention.

  Since the second embodiment is almost the same as the first embodiment, only different points will be described, and the same components are denoted by the same reference numerals and description thereof will be omitted.

  As shown in FIG. 3, the LED 12 of this embodiment is configured by combining an LED element that emits ultraviolet light and a phosphor that emits three primary colors of red, green, and blue, and has three colors of red, green, and blue. Is an element that emits white light, and is different from the LED 2 of the first embodiment.

  Further, the optical system 1A of the endoscope apparatus according to the present embodiment includes an LED 12 that emits white light, a condensing element 3 that condenses light emitted from the LED 12, and a condensing element 3 that collects the light. A light guide 4 that transmits the emitted light from one end and irradiates from the other end, the light emitted from the LED 12 is irradiated through an optical path including the condensing element 3 and the light guide 4, and A transparent solid fluorescent element 15 containing a phosphor is disposed on the irradiation surface (other end surface) of the light guide 4 in the optical path.

  Further, in the optical system 1A of the endoscope apparatus, the solid-state fluorescent element 15 has a light emission peak at a predetermined wavelength in a deep red region of a wavelength of 650 [nm] to 750 [nm] due to ultraviolet rays of incident light. It has luminous performance. The solid fluorescent element 15 is a transparent glass member in which semiconductor nanoparticles of cadmium telluride (CdTe) having a diameter of about 7 nm are dispersed and contained. The solid fluorescent element 15 is a circular plane, and a wavelength-selective reflecting film 17 that reflects only the generated deep red light is deposited on the surface facing the light guide 4.

  The operation of the optical system 1A of the endoscope apparatus of the present embodiment having such a configuration will be described.

  When a current is supplied from the LED drive circuit 6, the LED 12 emits white light. The emitted light is collected by the condenser lens 3 and enters one end surface of the light guide 4. Then, the incident light is transmitted through the light guide 4. The light transmitted through the light guide 4 enters the fluorescent solid element 15 from the irradiation surface (the other end surface).

  The fluorescent solid element 15 is excited by the ultraviolet component of the light incident from the light guide 4 and generates light having an emission peak in a deep red region having a wavelength of 650 to 750 [nm]. The light incident on the fluorescent solid element 15 and the deep red light generated inside the fluorescent solid element 15 are combined to illuminate an observation object (not shown).

  The illuminated light spectrum is the same as in Example 1 in that it is possible to obtain red illumination light having a high color rendering property that exhibits an emission peak at a predetermined wavelength in the deep red region.

  According to the endoscope apparatus of the present embodiment configured as described above, illumination with a high color rendering property is rich in a red component in which white light emitted from the LED 12 and deep red light emitted from the fluorescent solid-state element 15 are synthesized. Since light is irradiated, it is possible to present accurate information necessary for diagnosing a lesion.

  Further, in the endoscope apparatus of the present embodiment, since the fluorescent solid element 15 is excited by the light emitted from one white LED 12 and also serves as illumination light, the number of components is small and the structure is simple and inexpensive. An endoscope apparatus can be obtained.

  The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

The figure which shows the partial structure of the optical system of the endoscope apparatus which concerns on Example 1 of this invention. 1 is a characteristic diagram for explaining the optical spectrum of the optical system of FIG. The figure which shows the partial structure of the optical system of the endoscope apparatus which concerns on Example 2 of this invention. The characteristic diagram which shows the light spectrum of white LED which combined the LED element which emits blue, and the fluorescent substance which emits yellow

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A ... Optical system of endoscope apparatus 2,12 ... LED
3 ... Condensing element 4 ... Light guide 5, 15 ... Fluorescent solid-state element 7 ... Reflective film 17 ... Wavelength selective reflective film Agent Attorney Susumu Ito

Claims (4)

A semiconductor light emitting device that emits white light;
A condensing element for condensing the light emitted from the semiconductor light emitting element;
A light guide that transmits light collected from one end and radiates from the other end, and
In an endoscope apparatus having a configuration in which light emitted from the semiconductor light emitting element is irradiated through an optical path including the light collecting element and the light guide,
An endoscope apparatus, wherein a transparent solid fluorescent element containing a phosphor is disposed in the optical path. The endoscope apparatus according to claim 1, wherein the solid-state fluorescent element has a light emission peak in a deep red region having a wavelength of 650 [nm] to 750 [nm]. The endoscope apparatus according to claim 1, wherein the solid fluorescent element is disposed between the light condensing element and one end of the light guide. The endoscope apparatus according to claim 1, wherein the solid fluorescent element is disposed on the other end irradiation side of the light guide.

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