JP2007249065A - Led illuminator for optical microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminator for an optical microscope, the illuminator using a silicone based resin enclosure type LED element as a light source, or to provide the optical microscope having such an illuminating part. <P>SOLUTION: The illuminator for the optical microscope includes: a casing 22 which can be provided in the optical microscope; a base part 16 arranged in the casing and to which at least one silicone based resin enclosure type LED element is fixed; and a collector lens 26 arranged on an aperture of the casing, on the side opposite from the base part across the LED element, and a space between the collector lens and the base part is sealed in the casing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical microscope, and more particularly to an illumination device for an optical microscope.

  Due to recent advances in semiconductor technology, high-power LEDs (light-emitting diodes) can be obtained at low cost, and the emission wavelengths of LEDs have become diversified. Attempts have been made to adopt LEDs as the light source in place of conventional halogen lamps, mercury lamps, xenon lamps and the like. As is well known, LEDs have the advantages of greater mechanical strength, smaller dimensions, lower light emission, and longer life compared to light bulbs such as halogen lamps, and the emission wavelength is voltage-dependent. Therefore, it is expected to be very convenient as a light source for illumination of an optical microscope in which chromatic aberration of the lens is a problem (the color temperature does not substantially change even if the brightness is changed). Furthermore, since the heat generated from the light source of the LED is very small compared to that of a light bulb, observation of the sample with an optical microscope (especially observation of biological samples and other samples sensitive to temperature changes). Suitable for An example of using such an optical microscope as a light source mainly for bright-field observation can be found in Non-Patent Document 1 below, for example.

The LED is usually a small, for example, rectangular semiconductor chip, and when used as a lighting device, the LED is encapsulated in a transparent plastic resin or glass so that the semiconductor chip itself is not exposed, and dust and dirt adhere to it. And is protected from mechanical shocks. In particular, when encapsulated with resin, the resin is shaped like a hemisphere, and functions as a lens that collects light emitted from the LED. Thus, the prepared LED element (hereinafter referred to as “LED element” for the purpose of distinguishing the device in which the LED is encapsulated in a resin or the like from the semiconductor chip of the LED) is appropriately fixed on the substrate, It is installed in an arbitrary box and used as a lighting device (see, for example, Patent Document 1). Although the amount of heat generated by the LED is smaller than that of a light bulb, the LED itself or the LED element becoming overheated should be avoided because it shortens the life of the LED element. For example, in the case of the optical microscope described in Non-Patent Document 1, the illumination unit has a structure that allows air to flow around the plastic resin LED element fixed on the substrate, and heat generated from the LED itself. Is configured to dissipate heat. (The type of LED elements encapsulated in plastic resin is used for general LED lighting devices that transmit visible light sufficiently and are inexpensive to manufacture and obtain. Probably because it was easily available.)
Japanese Patent Publication No. 4-36595 Research and clinical biological microscope ECLIPSE 50i / 55i [Search February 24, 2006] <URL: http://www.nikon-instruments.jp/jpn/page/products/50i55i.aspx]

The light source of the illumination device of the optical microscope is preferably capable of illuminating not only visible light but also ultraviolet light or infrared light, and can withstand observation in a long time or in various environments. It is also desired to be resistant to heat and to be resistant to humidity and chemical changes (against surrounding gases, etc.). However, it is generally difficult to satisfy a desired condition for a light source of an illumination device for an optical microscope by using a plastic resin-encapsulated LED element. In the case of glass-sealed LED elements, illumination with ultraviolet light or infrared light is also possible, but the price is high, and the glass encapsulating the LED is processed so as to function as a condenser lens. Generally, it is not distributed and is difficult to obtain. Furthermore, LED elements etc. are based on the Rhos (Restricting the use of Hazardous
Substances: Hazardous Substances Control Directive (European Union Enforcement Directive), etc., must be met, but currently available plastic or glass-encapsulated LED elements may not always take such environmental measures. Many.

  In recent years, LED elements (silicon-based resin-encapsulated LED elements) in which LEDs are encapsulated with a silicon-based resin have begun to appear as solutions for the problems of the plastic or glass-encapsulated LED elements. In the case of such a silicon-based resin-encapsulated LED element, the silicon-based resin encapsulating the LED is significantly less deteriorated by ultraviolet light than plastic resin, and has good ultraviolet and infrared light transmittance. Illumination with light or infrared light is also possible. In addition, the silicon-based resin-encapsulated LED element is excellent in heat resistance and environmental change resistance, and can be easily processed so that the silicon-based resin medium encapsulating the LED functions as a condensing lens. Many of them meet the standards. Accordingly, the silicon-based resin-encapsulated LED element can be advantageously used as a light source of an illumination device for an optical microscope, instead of a plastic or glass-encapsulated LED element.

  However, the silicon-based resin-encapsulated LED element has a property of easily adsorbing dust on the surface. In particular, during light emitting operation, static electricity may be generated on the surface of the light source and dust may be attracted. Therefore, it is preferable to wipe off dust and dirt on the surface as appropriate. Generally, it is difficult to wipe off dust once adsorbed with a solvent or the like. Therefore, when a silicon-based resin-encapsulated LED element is used as the light source of an illumination device for an optical microscope, it is necessary to consider the problem of dust adsorption on the surface of the element.

  According to the present invention, an illumination device for an optical microscope using a silicon-based resin-encapsulated LED element as a light source or an optical microscope having such an illumination unit is provided.

  The illumination device for an optical microscope of the present invention includes a box that can be provided in the optical microscope, a base that is arranged in the box and has at least one LED element fixed thereto, and is opposite to the base across the LED element. And a collector lens disposed in the opening of the side box. As the LED element, a silicon-based resin-encapsulated LED element, that is, an LED encapsulated with a silicon-based resin is employed, and the LED element is disposed between the collector lens and the base portion in the box. And is sealed from the outside. Thus, according to the illumination device of the present invention, it is possible to stably use not only visible light but also ultraviolet light and infrared light as illumination light, that is, the advantage of the silicon-based resin-encapsulated LED element. In addition, by adopting a silicon-based resin-encapsulated LED element having good heat resistance and environmental resistance change performance, the life of the lighting device is extended, which is economically advantageous. Since the LED element itself is isolated from the atmosphere or the surrounding atmosphere, and the flow of external air on the LED element surface is blocked, dust and dirt adhere to the surface of the LED element during use of the device. This eliminates the need for the user to remove dust and dirt during use. Furthermore, the adoption of the silicon-based resin-encapsulated LED element provides an illumination device that satisfies environmental standards such as Rohs.

  In the lighting device of the present invention described above, the power supply to the LED element is provided with a means for transmitting an appropriate power through the base portion. It is preferable that the wiring hole is perforated through a part of the box or a part of the base part, and the wiring hole is sealed to prevent the flow of gas. As the instrument to be sealed, for example, a cable fixture that can appropriately seal the hole may be used.

  In the above lighting device, the space between the collector lens and the base portion in the box may be ambient air during manufacture and assembly of the lighting device. In the case of continuing lighting, gas such as oxygen in the air or moisture may deteriorate the silicon surface, so that it may be preferably filled with an inert gas or dried. In particular, if the expansion of gas in the space becomes a problem due to heat generation, the space may be maintained in a vacuum. On the other hand, in order to prevent the inflow of air from the outside, the air or gas in the space may be held at a high pressure.

  As already described, the LED element may be deteriorated when it is overheated to shorten its life. The amount of heat generated by the LED element itself is slightly weaker than that of a lamp, but when used for a long time, heat accumulates and the element becomes overheated. Therefore, in the present invention described above, a heat radiating fin may be provided in the base portion so that heat generated by the LED element fixed on the base portion can be radiated. Moreover, the base part is comprised with the material with high heat conductivity, and, thereby, the thermal radiation effect may be increased.

  The technical idea of the illumination device of the present invention described above may be applied to an illumination unit configured integrally with an optical microscope. In that case, the optical microscope of the present invention is provided with an optical path for passing illumination light and an opening provided at an end of the optical path, and at least one silicon-based resin is provided in the opening. The base portion to which the LED element formed by encapsulating the LED is fixed is arranged with the LED element facing inward of the optical microscope. The collector lens provided on the emission side when viewed from the light source in the optical path is disposed so as to sandwich the base and the LED element, and the space between the collector lens including the LED element and the base is sealed. In such a case, it is preferable that the cable electrically connected to the LED element passes through the wiring hole drilled in a part of the base part, and the wiring hole is sealed to prevent the flow of gas. The space between the collector lens and the base part in the optical path is filled with an inert gas, evacuated, kept at a high pressure, or dried for the same reason as above. It may be in the state which was made. Further, for the purpose of heat dissipation of the LED element, the base portion may be provided with heat radiation fins, or the base portion may be made of a material having high thermal conductivity.

  At present, in an optical microscope using an LED element as a light source for illumination, as already mentioned, the LED element is of a plastic resin-encapsulated type, and therefore mainly for bright field observation or transmitted light observation. It is used as a substitute for halogen lamps. However, since the illumination device or the optical microscope of the present invention employs a silicon-based resin-encapsulated LED element capable of ultraviolet illumination, fluorescence observation using various fluorescent dyes or observation of autofluorescence of a biological sample is possible. Thus, the light source can be used not only as a substitute for a halogen lamp but also as a lighting device in place of a mercury lamp, a xenon lamp or a laser. Such illumination is possible even with a glass-encapsulated LED element that transmits ultraviolet light to some extent and is less deteriorated by ultraviolet light. However, from the viewpoint of the manufacturing cost of the LED element itself and the ease of processing of the encapsulating medium, a silicon resin A lighting device using an encapsulated LED element is more advantageous and convenient.

  Furthermore, in the illuminating device or optical microscope of the present invention, the LED element is disposed in a sealed space isolated from the external air. Accumulation of dust and dirt on the surface of the LED element due to the above action is avoided, so that maintenance of the lighting device is unnecessary or extremely easy. Furthermore, since there is no circulation of external air around the LED element, the deterioration of the LED element surface will be greatly reduced or delayed, and therefore, the useful life as the illumination light source of the device (if the surface becomes cloudy due to deterioration, Before the life of the semiconductor chip comes to an end, it can no longer be used as a lighting device.).

  Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention.

  The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings. In the figure, the same reference numerals indicate the same parts.

  FIG. 1 is a front view (A) of an illumination device for an optical microscope (so-called “lamp house”) 10 that is detachably attached to an optical microscope that is one of preferred embodiments of the present invention. And side sectional drawing (B) is shown typically. With reference to the figure, a silicon-based resin-encapsulated LED element 12 is fixed on a substrate 14 to which a cable 18 for supplying power to the LED element is electrically connected, for example, by soldering. In addition, it is disposed on the base portion 16 via a heat conductive grease or the like. The base portion 16 has a surface 20 threaded on the outer periphery and a surface 20 ′ that fits into the box 22 to secure the center position of the optical axis, and the LED element 12 is a substantially cylindrical box 22. It is screwed into one opening of the box 22 so as to enter the inside. Inside the box 22, a collector lens 26 is provided at a position facing the base portion 16 with the LED element 12 interposed therebetween, and the collector lens 26 has an outer periphery that is in close contact with the inner wall of the box 22. The outer periphery of the collector lens 26 and the inner wall of the box 22 are sealed by vacuum packing and a sealing ring 28.

  On the other hand, complementary circumferential shoulder portions are respectively provided on the outer wall of the base portion 16 and the inner wall of the box 22 and are engaged with each other with the vacuum packing and the sealing ring 30 interposed therebetween. The cable 18 that supplies power to the LED element 12 passes through the wiring hole 32 drilled in the base portion 16 and is connected to a power supply device (not shown) outside the lighting device. In the wiring hole 32, it is preferable that the contact surface between the substrate 14 and the base portion 16 is sealed to prevent the air flow, but the outer end port of the wiring hole 32 is sealed even if this is not the case. It is preferably sealed by means 34 such as an instrument or bushing for fixing the cable as possible. Thus, the space between the collector lens 26 and the base portion 16 in the box 22 where the LED element 12 exists is sealed, and air circulation from the outside is prevented. After the device is assembled (the assembly may be preferably performed in a clean room), dust and dirt are prevented from entering near the surface of the LED element, and dust and dirt adsorbed on the surface can be removed. The difficulty of the silicon-based resin-encapsulated LED element, which is difficult, eliminates the need for care during use. In the example of FIG. 1 (B), the wiring hole 32 is provided in the base portion 16, but as shown in FIG. 1 (C), it arbitrarily penetrates from the inner wall to the outer wall of the box. It's okay. In this case, the base portion 16 has no threaded surface 20 and is fixed by one or a plurality of set screws 100.

  Since the silicon-based resin medium transmits not only visible light but also ultraviolet light or infrared light, the silicon-based resin-encapsulated LED element can be used as an illumination light source for ultraviolet light or infrared light. Therefore, according to the illumination device of the present invention, observation using ultraviolet light or infrared light in an optical microscope can be performed by LED illumination. Moreover, an LED illumination apparatus is comprised with respect to the light of various wavelengths by using what apply | coated the fluorescent pigment | dye which has a desired light emission wavelength on the LED chip surface of an LED element. As already described, the LED illumination device is smaller and lighter than a conventional lamp house using a halogen lamp. Therefore, a plurality of LED illumination devices for light of various wavelengths are prepared, before and after observation, or during observation. It is also easy to replace a plurality of lighting devices as appropriate. In the embodiment of the present invention, the LED element suitably used is, for example, LUXEON (registered trademark) K2 manufactured by Lumileds, but is not limited thereto.

  The space in the box between the collector lens 26 and the base part 16 may be normal air, but may preferably be filled with an inert gas such as nitrogen or argon. As described above, the illumination device of the present invention can be observed using ultraviolet light. In that case, if the space in the box between the collector lens 26 and the base portion 16 is filled with an inert gas, it is possible to further delay the deterioration of the resin due to ultraviolet light. The lifetime of the device will be extended. Similarly, such a space may be in a vacuum state or is preferably dried by arranging a desiccant or the like to remove moisture. Conversely, the space in the box between the collector lens 26 and the base portion 16 may be maintained at a high pressure in order to avoid the inflow of air from the outside. Further, although not shown, a box or a part of the base part that forms a space in the box between the collector lens 26 and the base part 16 may be formed of an elastic material such as a rubber sheet. . In this case, the increase in the gas pressure in the space in the box due to the heat generated by the LED is alleviated.

  As already described, when the LED element is overheated, the LED may be damaged by heat. In the above-described lighting device of the present invention, since the LED elements are arranged in a sealed space, it is not possible to dissipate heat by circulating external air as before. Therefore, the base portion 16 of the lighting device is preferably formed of a material having high thermal conductivity, for example, a metal material such as aluminum. In addition, as shown in FIG. 1D, heat radiation fins may be provided on the base so as to avoid overheating of the LED elements.

  In the lighting device of the present invention described above, it should be noted that since the exit side of the space in which the LED element is enclosed is composed of the collector lens 26, the number of members required for the means for isolating the LED element from the external air is reduced. (Since the LED element is small, a space for providing the collector lens 26 as shown in the figure is secured. In order to obtain a desired luminous flux, it is arbitrarily indicated by a broken line after the collector lens 26. A condensing lens 101 or an excitation filter 102 having an interference film that transmits only light of a selected wavelength, and a shutter 103 that opens when the illumination device 10 is attached to the microscope body and is closed when the illumination device 10 is removed. It may be provided.

  FIG. 2A shows a side cross-sectional view of the illumination apparatus 10 of the type inserted into the optical path 44 of the illumination light of the optical microscope 38 as illustrated in FIG. 2B. The basic configuration is the same as that of the illumination device of FIG. 1 (for the sake of simplicity, description of the cable 18 and the like is omitted), but on the outer periphery of the box 22 so as to be positioned inside the microscope. A flange 40 is provided. Optionally, for example, disk-shaped heat radiation fins 42 may be provided.

  FIG. 3 shows an example in which the base portion 16 to which the LED element is fixed is directly attached to the opening end 46 of the optical path 44 of the illumination light of the optical microscope. In this case, although not shown, a wiring hole for passing a power supply cable may be provided in the base portion 16, but a part of the wall of the optical path of the illumination light of the optical microscope is perforated, As in the example of FIG. 1, a wiring hole that is sealed by means such as an instrument or bushing for fixing the cable so as to be sealed in an arbitrary manner may be provided.

  Although the above description has been made in relation to the embodiment of the present invention, many modifications and changes can be easily made by those skilled in the art, and the present invention is limited to the embodiment exemplified above. It will be apparent that the invention is not limited and applies to various devices without departing from the inventive concept.

In particular, the present invention includes the following aspects.
3. The illumination device according to claim 1, wherein a space between the collector lens and the base portion in the box is filled with an inert gas.
3. The lighting device according to claim 1, wherein a vacuum is provided between the collector lens and the base portion in the box.
3. The illumination device according to claim 1, wherein a space between the collector lens and the base portion in the box is maintained at a high pressure.
3. The illumination device according to claim 1, wherein a space between the collector lens and the base portion in the box is dried.
3. The lighting device according to claim 1, wherein a radiating fin is provided on the base portion. 4.
3. The apparatus according to claim 1, wherein the base is made of a material having high thermal conductivity.
3. The illumination device according to claim 1 or 2, wherein the box is detachable from the optical microscope.
5. The optical microscope according to claim 3, wherein a space between the collector lens and the base portion in the optical path is filled with an inert gas.
5. The optical microscope according to claim 3, wherein a vacuum is provided between the collector lens and the base portion in the optical path.
5. The optical microscope according to claim 3, wherein a space between the collector lens and the base portion in the optical path is maintained at a high pressure.
5. The optical microscope according to claim 3, wherein a space between the collector lens and the base portion in the optical path is dried.
5. The optical microscope according to claim 3, wherein a radiation fin is provided on the base portion.
5. The optical microscope according to claim 3, wherein the base is made of a material having high thermal conductivity.

FIG. 1A is a front view of an illumination device for an optical microscope which is one of the preferred embodiments of the present invention, and FIG. 1B shows a side sectional view thereof. What is drawn with a broken line is a condensing lens, an excitation filter, a shutter, etc. that are optionally provided. 1C and 1D are side sectional views of the modified example of FIG. FIG. 2A is a side sectional view of an illuminating device which is another preferred embodiment according to the present invention which is provided in the optical path of illumination light of an optical microscope, and FIG. The state which installed the illuminating device of 2 (A) in the optical microscope is shown. Only the vicinity of the lighting device is broken and a cross-sectional view is drawn. In the figure, the broken line indicates the inner wall and mirror of the optical path of the illumination light in the microscope. FIG. 3 is a cross-sectional view of the vicinity of the entrance end of the optical path of the illumination light of the optical microscope, and shows an example in which a base portion that carries an LED element is directly provided at the entrance end.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Illuminating device 12 ... Silicone resin enclosure type | mold LED element 14 ... Board | substrate 16 ... Base part 18 ... Cable 22 ... Box 26 ... Collector lens 28 ... Vacuum packing 30 ... Vacuum packing 32 ... Wiring hole 34 ... Cable which can be sealed Fixing device (bush)
36 ... Radiating fin 38 ... Optical microscope 42 ... Radiating fin 44 ... Optical path

Claims (4)

  An illuminating device for an optical microscope, comprising a box that can be provided in the optical microscope, and a base portion to which at least one LED element is fixed, which is disposed in the box and encapsulates an LED with a silicon-based resin And a collector lens disposed in the opening of the box opposite to the base part across the LED element, between the collector lens and the base part in the box An illumination device for an optical microscope, characterized in that a space is sealed.   The lighting device according to claim 1, wherein a cable electrically connected to the LED element passes through a wiring hole drilled in a part of the box or a part of the base part, and the wiring hole A device characterized in that it is sealed by a cable fixture that can be sealed to prevent the flow of gas.   An optical microscope having an optical path for passing illumination light of the optical microscope, an opening provided at an end of the optical path, and at least one LED element formed by encapsulating an LED with a silicon-based resin is fixed. A base portion disposed with the LED element facing the opening, and a collector lens disposed on the optical path opposite to the base portion with the LED element interposed therebetween, An optical microscope, wherein a space between the collector lens and the base portion is sealed. 4. The optical microscope according to claim 3, wherein the wiring electrically connected to the LED element passes through the wiring hole drilled in a part of the base portion, and the wiring hole prevents the gas from flowing. An optical microscope which is sealed by a sealable cable fixture.

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