JP4817632B2 - LED fiber light source device and endoscope using the same - Google Patents

Description

  The present invention is an LED fiber light source device for industrial or medical use and an endoscope using the same. Used as a medical endoscope illumination light source having a main lamp and a sub lamp.

  Medical endoscopes illuminate the inside of the body with white light (illumination optical system) and obtain an in-vivo image with a CCD camera or the like. The illumination optical system is a high-intensity lamp such as a xenon lamp, a condensing lens (including a reflection mirror) that condenses the lamp output, a light guide composed of an optical fiber that guides the collected light into the body, and a light It consists of an illumination lens for irradiating the body with the output from the guide.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a method that enables the examination of the endoscopic examination to be continued by turning on the sub lamp even when power is not supplied from a commercial power source due to a power failure or the like. Although not shown, the main lamp is a xenon lamp or a halogen lamp. The sub lamp is an LED, and the sub lamp is retracted from the optical path of the main lamp, and is configured to be used by moving the sub lamp onto the optical path of the main lamp during a power failure.

  As described above, high-intensity lamps used in illumination optical systems also propose illumination optical systems that use LEDs in accordance with the development status of high-power LEDs due to problems such as heat generation, large power consumption, and large shapes. It is being done.

  Patent Document 2 proposes an endoscope illumination light source using a plurality of LEDs. There has been proposed an assembling method in which a plurality of LEDs are arranged and light emitted from the LEDs is introduced into an optical glass fiber using a reflecting mirror. As described above, attempts have been made to increase the output by using a plurality of LEDs, but it is considered that the light collection efficiency is very bad, and no measures are taken against power failure.

FIG. 4 shows a light source device for an endoscope using three-color LEDs disclosed in Patent Document 3.

  If you prepare three (31R, 31G, 31B) optical fibers corresponding to each of the three colors R (red) 30R, G (green) 30G, and B (blue) 30B as the LED light emitting unit, It can be used for an endoscope apparatus. A field sequential endoscope is an apparatus that switches R, G, and B illumination light, sequentially irradiates the subject, images and observes the subject, and provides a high-quality image.

  For example, when a purple or blue light is applied, normal tissue emits fluorescence, but a cancerous part is difficult to emit fluorescence and is difficult to see in the dark. Cancer can be found by comparing an image obtained by applying blue light with an image obtained by combining images obtained by applying three colors (corresponding to an image obtained by white light).

Further, according to Non-Patent Document 1, Narrow Band Imaging (NBI) of an endoscope is discussed, and the light source wavelength dependency of endoscopic examination is described. An endoscope is a skin inspection of a part to be measured, and it is important to have means that can change the wavelength of the light source in order to make it easier to inspect the skin.
JP 2002-72106 A Japanese Patent Laid-Open No. 2003-23596 Japanese Patent No. 3088165 “Current Status and Future Prospects of Biomedical Optical Research” p43-51, Optoelectronic Industry and Technology Promotion Association, March 2004

  A light source for an endoscope is required to have a backup configuration in which a sub lamp is lit even when a main lamp is not lit, or a high-intensity light source and a light source wavelength that can be changed.

  The conventional backup configuration is complicated because the sub lamp is moved mechanically. Although LEDs are advantageous for miniaturization, in the current LED output, a plurality of LEDs are used to increase the luminance. In Patent Document 2 of a light source device using a conventional LED, the output of a plurality of LEDs is not collimated, and a large light source of the entire LED is condensed, so the light collection efficiency is very poor. In Patent Document 3, R (red), G (green), and B (blue) LEDs are prepared to change the light source wavelength. However, since three optical fibers are prepared, the insertion portion is thick. turn into.

In order to solve the above-mentioned demand, firstly, it is an object to develop a method of bundling a plurality of LEDs having different wavelengths in order to change the light source wavelength with high brightness .

Next, an object of the present invention is to develop a structure that eliminates mechanical movement of the sub lamp by laying out the main lamp and the sub lamp so as to collect light on the same optical path as a backup configuration .

The present invention has been made to solve these problems, collimates the multiple LED, a light guide means for bundling the output light of the plurality of LED, each output light from the light guide means bundled a collimating means comprising a collimating lens or a reflecting mirror, and focusing means output light composed of the condenser lens or the condenser mirror for collecting light from said collimating means, an optical fiber disposed near the focal point of the focusing means have a, the plurality of LED is characterized in that it has a main lamp consisting to use at all times L ED, and a sub-lamp composed of the main lamp and switched usable other the LED.

  Further, the apparatus has means for detecting a malfunction of the main lamp, and means for automatically switching to lighting of the sub lamp according to the malfunction.

  The main lamp and the sub lamp include a red LED and a white LED that excites a yellow phosphor with a blue LED.

  In addition, the main lamp and the sub lamp include three or more colors among red LED, blue LED, green LED, orange LED, and cyan LED.

  In addition, a wavelength combining mirror for combining the output lights from the plurality of LEDs is disposed between the collimating unit and the condensing unit.

  Further, the LED fiber light source device is used as a light source.

  According to the present invention, there is no moving part when switching between the main lamp and the sub lamp, and the light source device for endoscope can be reduced in size and improved in reliability.

  A high-luminance endoscope in which the wavelength of the light source can be changed by bundling red LEDs and LEDs mainly containing blue or LEDs of several colors with a condensing lens or a wavelength synthesis mirror. A light source device can be provided.

  FIG. 1 is a block diagram showing a first embodiment of the present invention.

  FIG. 1A is an overall configuration diagram, and FIG. 1B shows the layout of LEDs 1a and 1b in detail.

  First, according to the present invention, a plurality of fixed LEDs, a collimating means including a collimating lens or a reflecting mirror for collimating each output light from the LED, a condenser lens for collecting the output light from the collimating means, or a collecting lens. A main lamp formed of a part of the plurality of LEDs that is always used, and one end of an optical fiber disposed near the focal point of the light collecting means. And a sub lamp made of other LEDs that can be used by switching.

Further, that having a light guiding means through the optical fiber between the plurality of LED and said collimating means.

  Since the LED 1a is used as the main lamp and the LED 1b is used as the sub lamp, and the LED of FIG. 1 (a) represents the cross-sectional view of FIG. 1 (b), only two LEDs are shown.

  1A includes LEDs 1a and 1b, a collimator lens 2, a condenser lens 3, an optical fiber 4, an LED driver 5, an LED abnormality detection circuit 6, and optical fibers 7a and 7b.

  The LEDs 1a and 1b emit white light and become light close to parallel light by the collimator lens 2 via the optical fibers 7a and 7b, respectively, and are collected by the condenser lens 3 and guided to one end of the optical fiber 4 and output to the optical fiber 4 White light is output from the side.

The LED used here requires a heat sink or the like for its heat generation countermeasure, and assumes an outer diameter of 10 mm or more. When the outer diameter of the LED is large, the output light of the LEDs 1a and 1b is collected by the optical fibers 7a and 7b, and the fibers 7a and 7b are placed close to each other and placed in the collimator lens 2, thereby reducing the light beam in the condenser lens 3. It is preferable that the present invention includes means for detecting a malfunction of the main lamp and means for automatically switching to lighting of the sub lamp according to the malfunction.

  The LED driver 5 is supplied with a commercial power supply (not shown) and normally turns on the LED 1a as the main lamp. However, when the LED abnormality detection circuit 6 detects a failure of the LED 1a, the LED 1b as the sub lamp is turned on and the LED 1a is turned on. Turn off the light.

  In addition, with this configuration, it is possible to switch between the main lamp and the sub lamp without mechanical operation.

  Although detailed explanation of the LED abnormality detection circuit 6 is omitted, it can be determined from the luminance signal of the CCD camera built in the endoscope, or a circuit for monitoring a part of the light amount of the LED 1 can be added. Is possible.

  In the above embodiment, the collimator lens 2 is used as the collimator means, but it is also possible to increase the light collection degree by adding a parabolic reflecting mirror.

  In the present invention, the main lamp and the sub lamp preferably include a red LED and a white LED that excites a yellow phosphor with a blue LED.

  In the present invention, it is preferable that the main lamp and the sub lamp include three or more colors among red LED, blue LED, green LED, orange LED, and cyan LED.

  In the above embodiment, the LED uses a white LED. However, the number of LEDs is increased, a combination of a plurality of colors, for example, a red LED and a white LED that excites a yellow phosphor with a blue LED, a red LED, and a green LED. Since LEDs and blue LEDs can be used and the lighting of red, green and blue LEDs can be sequentially switched and used as a surface-sequential type endoscope light source, the application is advantageous depending on the application.

  In this way, the main lamp and the sub lamp are guided by the optical fiber 7 and are condensed on one end of the optical fiber 4 by the condensing lens 3, so that the LED 1 light is easily collected on the optical fiber 4, When the main lamp 1a breaks down, there is no moving part for switching to the sub lamp 1b, and there is an effect of downsizing the device and improving reliability.

  In addition, the output of a plurality of LEDs can be bundled, the output (brightness) of the light source device can be increased, the wavelength of the light source can be changed by selecting the LED to be turned on, and a surface sequential light source having no moving parts can be provided. effective.

  An example will be described based on the embodiment of FIG.

FIG. 2 shows the emission spectrum waveform of the white LED used.

  The LED 1 is a blue LED coated with a yellow phosphor and outputs white light. The output of one LED is a 120 lumen high luminous flux LED, but the output beam divergence angle from LED 1 is omnidirectional (120 degrees or more). Here, the optical fiber 7 is a plaque fiber (POF) having an outer diameter of 2 mm, and is disposed directly on the end face of the LED 1 and led to the collimator lens 2.

  The LED 1 is a bullet type, and a heat sink (φ20 mm) is attached to the bullet type lens portion (φ5 mm). For this reason, the LEDs are arranged at intervals of 20 mm.

  The collimator lens 2 and the condenser lens 3 also use plano-convex lenses.

  The optical fiber 4 is a multi-component glass bundle fiber for a light guide having a diameter of 2 mm and has a length of 3 m. Accordingly, this optical system is a lens system having a light source size of 4 mm in which two fibers 7 having a diameter of 2 mm are bundled, and the image side is a 2 mm size of the fiber 4 and a lens system having a magnification of 0.5.

  When the optical fiber 7 is not used as a comparative example, the light source size is 20 mm, the lens system magnification is 0.1, the magnification difference is 5 times, and the amount of light that can be condensed on the end face of the fiber 4 is 1/25 (fiber 7 If there is no loss of

  That is, since it is equivalent to arranging the LEDs 1a and 1b close to the optical fiber 7, the size of the collimator lens 2 and the condenser lens 3 can be reduced, and as a result, there is an effect that the optical fiber 4 can be easily condensed.

  Further, although the LED 10a is normally lit, if the luminance signal of a CCD camera (not shown) is reduced by the LED abnormality detection circuit, it is determined that there is an abnormality and the LED 1b is switched.

  As a comparative example, in Patent Document 1, since the main lamp and the sub lamp are switched using mechanical means, the apparatus becomes complicated. However, this method can be switched only by an electric signal, and has high luminance and high reliability. There is an effect of providing a light source.

  As a comparative example, the method disclosed in Patent Document 3 uses three optical fibers, so the insertion portion of the endoscope becomes thick. In this method, the insertion portion is a single fiber. Therefore, there is an effect that the operability is improved with less burden on the subject.

  Further, since the main lamp and the sub lamp are also incorporated, there is no mechanical moving part as described above, and the reliability is improved.

It is a schematic diagram which shows 1st Embodiment of the LED fiber light source device in this invention. It is a graph which shows the emission spectrum of the used white LED. It is a graph which shows the emission spectrum of the used red LED. It is a schematic diagram which shows the light source device of the endoscope using 3 color LED of a prior art.

Explanation of symbols

1a, 1b: LED
2: Collimator lens 3: Condensing lens 4: Optical fiber 5: LED driver 6: LED abnormality detection circuit 7a, 7b: Optical fiber 10a, 10b, 10c: LED
11a, 11b, 11c: Collimator lenses 12a, 12b: Wavelength combining mirrors

Claims (6)

And multiple LED, a light guide means for bundling the output light of the plurality of LED, and the collimating means consisting collimating lens or a reflecting mirror for collimating the output light from the light guide means bundled, from the collimating means possess between focusing means consisting of the condenser lens or the condenser mirror condensing the output light, and an optical fiber disposed near the focal point of the focusing means, the plurality of LED's, to use at all times L An LED fiber light source device comprising: a main lamp made of ED; and a sub lamp made of another LED that can be used by switching to the main lamp. 2. The LED fiber light source device according to claim 1, further comprising means for detecting a malfunction of the main lamp and means for automatically switching to lighting of the sub lamp according to the malfunction. 3. The LED fiber light source device according to claim 1, wherein the main lamp and the sub lamp include a red LED and a white LED that excites a yellow phosphor with a blue LED. 3. The LED fiber light source device according to claim 1, wherein the main lamp and the sub lamp include three or more colors among red LED, blue LED, green LED, orange LED, and cyan LED. 5. The LED fiber light source device according to claim 1, wherein a wavelength combining mirror for combining output light from the plurality of LEDs is disposed between the collimating unit and the condensing unit. An endoscope using the LED fiber light source device according to any one of claims 1 to 5 as a light source.

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