WO2012173515A1

WO2012173515A1 - Lighting device

Info

Publication number: WO2012173515A1
Application number: PCT/RU2012/000272
Authority: WO
Original assignee: Общество С Ограниченной Ответственностью "Айсберг"
Priority date: 2011-06-14
Filing date: 2012-04-09
Publication date: 2012-12-20
Also published as: RU2011124111A

Abstract

The lighting device comprises a light source, which is in the form of a high-power light-emitting diode crystal and is mounted in a body, and a light guiding fiber bundle consisting of a high-aperture optical fiber having a planar end perpendicular to the fibers. Furthermore, the end of the fiber bundle is arranged in the direct vicinity of the exit surface of the crystal. The proximal end of the fiber bundle is enclosed in a rigid jacket, for example a metal jacket. In order to dissipate heat emitted by the light-emitting diode during luminescence, the body of the device is made from a material with a high thermal conductivity, for example from aluminum.

Description

LIGHTING DEVICE

The invention relates to the field of illuminators based on the use of fiber optics and LEDs. In particular, the invention relates to illuminators used to illuminate various cavities, including in medical and technical endoscopes (borescopes).

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For high-quality visual control of objects, their good lighting is necessary. In this regard, medical illuminators, as a rule, contain a powerful light source and a fiber optic bundle optically connected with it, transmitting light from the radiation source to a given zone.

For many years, for example, halogen, metal halide and xenon lamps with a power of 100-150 W and halogen lamps with a power of at least 250 W have been used as sources of light radiation in endoscopes. During the operation of the aforementioned lamp light sources, a large amount of heat is released, which determines their main disadvantage. Since the input end of the fiber lighting bundle must be protected from strong thermal influences, it is necessary to create cooling devices inside the light source. Other

The disadvantage of tube light sources is the need to collect the light flux using an optical system, filter it and focus on the input end of the lighting bundle.

An alternative method of lighting in an electronic endoscope is described in US Pat. No. 6,331,156. A tube containing multiple

LEDs elongated along the axis of the tube in line. Moreover, each LED is optically connected to an individual fiber conductor, stretched to the distal end of the endoscope, where an image sensor is located, the proximal end of which is connected to the tube, at the distal end of which all individual conductors are assembled into a single bundle. In one embodiment of this invention, the fiber core is located directly in front of the emitting LED, in another embodiment, there is a collection of optics between it and the LED. - The design of the illuminator is complex and expensive to manufacture, requires a large consumption of fiber. In addition, when using a large number of LEDs to obtain the desired illumination of the object, a large amount of heat is generated, the tube in which the LEDs are located heats up and heats the distal end of the endoscope.

Another example of the use of LEDs in medical illuminators is described in US patent application 2003/0231843. The application describes a lighting device used in a dental appliance performing vulcanization

polymeric materials. A lighting device contains many light emitting diodes, each of which is connected to a light-conducting fiber core, through which light enters a common radiating surface at the output of the device. In this case, the fiber core is located in close proximity to the radiating surface

LED. However, this device also uses additional optics to collect light in order to increase the intensity of the total light flux.

Also known is the invention described in international application WO 2006034171 and in US patent 7198397. Described "Method of installing a light source in the handle of the endoscope". In accordance with the invention, first, a part of the lens and part of the shell used to match the refractive indices are removed from the standard LED package, then an open LED is placed in the endoscope handle so that the emitting surface of the LED crystal is in contact with the contact end of the illuminating fiber bundle transmitting light to the working end of the endoscope. In accordance with the claims, the invention does not contain optics, such as lenses or mirrors, located between the light source and the fiber bundle. However, when describing embodiments of the invention, drawings and text explaining them are provided, from which it becomes clear that to increase the intensity of the light flux, it is necessary to use collecting optics. In particular, in the description of FIG. explaining the invention, it is said that in order to achieve maximum collection of light emitted by the LED, the lens and the connecting gel are first removed, revealing the LED crystal and its phosphorus coating. Then a plastic or glass cone (solid plastic or glass taper) is placed between the LED and the bundle

functioning as an adapter that collects almost all the emitted,. ,, LED stream and effectively directs it into a bundle that delivers light to the distal end of the device. In accordance with this invention, the crystal is mounted on a heat sink element. Energy is supplied to the crystal from the battery by wire. The harness is sealed with epoxy in a stainless steel cage. However, the cage may not be necessary if it is not necessary to group the fibers (for example, when instead of a plurality of fibers, one large fiber or a core is used). The polished end of the tow is in contact with the surface of the crystal and is as close to it as technically possible. However, there are light losses. Therefore, in another embodiment, the invention returns to the use of collecting optics, with the tourniquet being placed in close proximity to the lens. This allows you to collect enough light. However, the efficiency of such an optical transmission is low, and as a result, the coverage of the subject of interest will be less than in the previous case.

The invention described in international application WO 2006034171 and in US patent 7198397, the closest in technical essence to the claimed illuminator and taken as a prototype.

The technical task of the claimed invention is to increase the efficiency of a lighting device based on the use of LEDs and fiber optics, reduce the cost of its manufacture, save electrical energy consumed by the device and simplify its installation in any type of endoscopes and other devices where high-quality lighting of the object in question is required.

- The solution to this problem is achieved by the fact that the lighting device contains a light source installed in the housing in the form of an LED crystal and a light-conducting fiber bundle of high-aperture optical fiber, having a flat end face perpendicular to the fibers and located in close proximity to the radiating surface of the crystal.

To ensure a stable fixed relative position of the end of the fiber bundle and the radiating surface of the crystal, the proximal end of the fiber bundle is enclosed in a rigid clip, for example, metal.

In order to maximize the collection of emitted light, the size of the cross section of the end of the bundle corresponds to the size of the radiating surface of the crystal.

To remove the heat generated by the LED during the glow, the device casing is made of a material with a high coefficient of thermal conductivity, for example, aluminum.

To keep the proximal end of the fiber bundle in a position that ensures maximum collection and transmission of emitted light, the housing includes a sleeve with a Central hole to accommodate the proximal end of the fiber bundle, while the sleeve further has a side hole for the locking screw for fixing the aforementioned fiber bundle.

The essence of the claimed lighting device is illustrated in FIG. 1 to 4. In FIG. 1 shows a general view of a lighting device.

In FIG. 2 ′ is a cross-sectional view of a lighting device along its center line.

In FIG. 3 schematically shows the relative position of the LED crystal and the fiber bundle, side view. In FIG. 4 is a plan view of an LED crystal.

As shown in FIG. 1 and FIG. 2, the lighting device 1 comprises a housing 2 in which a light source in the form of a crystal 3 of an LED is mounted and fixed. The housing 2 in addition to the main function of the placement and protection of the elements of the device 1 additionally performs the function of a radiator to remove heat generated by the crystal 3 when light is emitted. In this regard, it is made of a material with a high coefficient of thermal conductivity, and its side surface is provided with ribs. The housing 2 also includes a sleeve 4 fixed therein, in the central opening of which is located the proximal end 5 of the fiber bundle b, which transmits the emitted light to the lighting object. The proximal end 5 of the bundle b is enclosed in a rigid clip 7. The shape of the proximal end 5 of the bundle b has a circular cross section. The clip 7 can be made in the form of a metal tube, for example, stainless steel. Other clip materials may be used, such as metals, heat-resistant alloys, or plastics. The following requirements are imposed on the shape of the bundle at the proximal end: the end of the bundle 8 should be flat, polished and generally perpendicular to the fibers grouped in the ferrule. Moreover, the shape of the tow at the distal end may be different depending on the purpose of the illuminator, in particular, it can be divided into separate branches to illuminate the object of study from different sides.

It is desirable that the area of the end face 8 of the fiber bundle b would completely cover the radiating surface of the crystal 3. Moreover, the fiber bundle b does not have c crystal 3 of direct mechanical contact, but located as close to its radiating surface as technically feasible. The sleeve 4, which serves as a retainer for the proximal end 5 of the fiber bundle b, can be fixed in the housing 2 of the lighting device 1 by any known method, for example, using screws 9. As can be seen from FIG. 1, the sleeve 4 has a through hole 10 with a screw thread for the locking screw 11, which provides rigid fixation of the fiber bundle b inside the sleeve, which, in turn, ensures the stability of the interaction of the optical bundle 6 with the crystal 3.

FIG. 3 and 4 explain the essence of this interaction. Crystal 3 has the shape of a square (Fig. 2), placed in the center of the standard substrate 12, equipped with

a centering frame 13. In the standard substrate 12, the elements 14 are made with leads 15 leading the current to the crystal.

The angle of radiation of crystals of the currently known high-power LEDs is approximately 120 ^° . Therefore, to prevent loss of emitted light, the angle within which the light can be transmitted by the optical fiber should be approximately the same. High aperture fiber used in accordance with

the present invention for the manufacture of fiber tow b, meets this requirement.

The present invention has been embodied as a lighting device for use in a flexible endoscope. The housing of the lighting device was made of aluminum. Its overall dimensions are partially determined by the dimensions, end ..

the surface of the endoscope body to which the illuminator is attached. In FIG. 1 shows the length n = 38.4 mm and the width d = 30.4 mm. The depth of the illuminator is selected taking into account

ensure effective heat dissipation and amounted to 30 mm. The experiment showed that the endoscope user can hold it in his hand for a long time, without feeling any discomfort from heating the case. The lighting device uses a 3 W Cree EZ 1000 LED crystal. The crystal is a square with a side of 1 mm, placed on the above-mentioned standard substrate containing two conductive tracks with leads at their ends for connection to a power source. In this case, the luminous crystal surface has the shape of a square with a side _; 960 microns.

Between the substrate 12 and the housing 2 was applied heat-conducting paste 16 (see Fig. 2). A light guide bundle with a diameter of 1, 34 mm was made of a LIFaTe C optical fiber having an angular aperture of 120 ^° . The harness was carried out using traditional technology. The fibers are assembled in a stainless steel ^* tube, the outer diameter of which is 2 mm, and the inner diameter is 1.5 mm, the length of the tube is 15 mm. The butt of the formed tourniquet is polished and sealed with epoxy. In this case, the flat surface of the end of the bundle is perpendicular to the fibers filling the bundle. When installing the harness in the body of the illuminator, alignment was carried out. Varying the position of the end of the fiber bundle relative to the surface of the crystal, we measured the intensity of the light flux using a photodetector, after which, in the position providing the maximum intensity, the illuminator was mounted on the body of a flexible endoscope, while its distal end was introduced into the trunk of the endoscope .. Amount of light measured a light meter at the distal end of the endoscope, amounted to 15,000 lux, i.e. significantly more than flexible endoscopes available on the modern market: In particular, the LOMO video gastroendoscope (WHERE - GWK - 40 - LOMO) uses a 2.5 mm diameter fiber with a 60 ^° aperture and

35 W metal halide lamp as a light source. The amount of light at the distal end of the endoscope, depending on the particular specimen, is (8000 - 9000) lux. At the same time, the manufactured sample of the illuminator based on a crystal of a high-power LED and high-aperture fiber required a significantly smaller amount of fiber both in diameter (fiber bundle is approximately 3.4 times thinner) and in length. The latter is explained by the fact that there is no need to guide the fiber from the endoscope body to the illuminator, because The inventive illuminator due to its low heating can be placed directly in the endoscope body, thus, the bundle becomes half as long. Another undoubted advantage is that the flexible endoscope sample prepared by the Applicant does not need a sufficiently complex cooling system, since such a need exists only when using powerful lamps as a light source. At the same time, energy consumption has significantly decreased than in the aforementioned LOMO endoscope.

Claims

CLAIM

1. A lighting device comprising a light source installed in the housing in the form of an LED crystal and a light guide fiber bundle of high aperture optical fiber having a flat end face perpendicular to the fibers and

located in close proximity to the radiating surface of the crystal.

2. The lighting device according to claim 1, characterized in that the proximal end of the fiber bundle is enclosed in a rigid clip, for example, metal.

3. The lighting device according to claim 1, characterized in that the size of the cross section of the end of the bundle corresponds to the size of the radiating surface of the crystal.

4. The lighting device according to claim 1, characterized in that the housing is made of a material with a high coefficient of thermal conductivity.

5. The lighting device according to claim 4, characterized in that the housing is made of aluminum.

6. The lighting device according to claim 1, characterized in that the housing includes a sleeve with a central hole for accommodating the proximal end of the fiber bundle, while the sleeve further has a lateral hole for a locking screw for fixing said fiber bundle.