JP2004039285A - Light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact light source device for lighting of an optical equipment such as an optical microscope and a CCD camera that is capable of freely inserting from the outside of the equipment. <P>SOLUTION: In the light source device, a light-emitting element group (1) made of many LEDs (1a) are arranged in annular form, and one end face (3b) of each wire (3a) constituting an optical fiber wire group is provided opposed to each light-emitting element (1a) constituting the light-emitting element group (1), and the spaces between the wires (3a) are in an unbound state and form a multi-branched light incidence part and a light exit part that is bound in the annular form is formed at the other end face (3c). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light source device including a light guide in which light emitting element groups (LED groups) and optical fiber wires are bundled. More specifically, the present invention particularly relates to a light source device for illuminating optical devices such as an optical microscope and a CCD camera, and further for illuminating an image.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an optical device such as an optical microscope (hereinafter sometimes simply referred to as “device”), an imaging device such as a CCD camera is attached to a central portion of an irradiation unit in order to image the irradiation unit. There are many. For this reason, it is necessary to arrange the light source for irradiating the object so as to avoid the CCD camera provided at the central portion of the irradiating section.
In order to meet this demand, it has been proposed to incorporate a light source in which a light emitting element group is arranged in a ring shape in a device. (See JP-A-2001-154103)
However, in this proposal, since the device itself was originally designed to be compact, there was not enough space for a built-in light source inside the device, so it was not possible to obtain a sufficient amount of light. There is also a problem that the size of the device is increased by that much, and deviates from the original compact design. In order to cope with this problem, it is conceivable to arrange a light guide composed of an optical fiber connected to the light emitting element group as a separate object at a position away from the device. However, in this case, the irradiation of the object is not oblique irradiation but oblique irradiation, so that illuminance unevenness occurs.
In view of the above, there has been a long-awaited need for a compact light source device that is not a built-in type or a separate type, but is an integrated type that can be directly attached to a device from the outside and that can obtain a sufficient amount of light without causing uneven illuminance. .
[0003]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a compact light source device that can be fitted from the outside of the device.
[0004]
[Means for Solving the Problems]
The present inventors have set at least a light guide as an emission surface in which one end face of an optical fiber strand group is opposed to a ring-shaped light emitting element group and the end face of the end of the strand group is bound in a ring shape. By providing an internal space in the longitudinal direction of the light guide composed of the element wire group, a compact light source device that can be fitted from the outside of the device has been provided.
[0005]
Thus, according to the present invention, a light source composed of a group of light emitting elements, and a light guide composed of a group of optical fiber wires, for allowing light from the light source to enter from one end face and exit from the other end face, And the light source device characterized by satisfying the following requirements a to d is provided.
a. The light emitting element group is arranged in a ring;
b. One end face of each of the optical fibers constituting the optical fiber group is opposed to and installed on each of the light emitting elements constituting the light emitting element group, and the wires are in a non-bound state to form a multi-branch incident portion. Doing things;
c. The other end face of the optical fiber group forms an emission portion bound in an annular shape;
And d. The internal annular space of the annular light emitting portion extends toward the light emitting element group arranged in the annular shape.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an example in which the light source device of the present invention is mounted on an optical microscope will be described with reference to the drawings.
FIG. 1 is a side view showing an example of the light source device of the present invention.
FIG. 2 is a plan view showing an arrangement state of the light emitting element group in FIG.
FIG. 3 is a plan view showing an arrangement state of the optical fiber group in FIG.
FIG. 4 is a partially enlarged view of FIG.
FIG. 5 is a side view showing a preferred embodiment of the light source device of the present invention.
FIG. 6 is a front view showing an example in which the light source device of the present invention is attached to a lens barrel of an optical microscope.
1 to 6, (1) denotes a light emitting element group (hereinafter, referred to as “LED group”), and (1a) denotes individual light emitting elements (hereinafter, “LED”) constituting the light emitting element group (1). , (2) is a mounting board for arranging the LED group (1) in a ring shape, (3) is a light guide comprising an optical fiber group (hereinafter referred to as “element group”), 3a) is an individual optical fiber (hereinafter referred to as "element") constituting the element group or a bundle of a plurality thereof, and (3b) is an element (3a) facing each element (1a). ), (3c) is a ring-shaped emission end formed at the end of the light guide (3), (4) is a mounting plate for making the wire (3a) face the LED (1a), and (5) is This is a fixture for rearranging the strands in a ring shape before the ring-shaped emission end (3b).
Here, as shown in FIG. 2, the LED group (1) is arranged in a ring shape on the LED mounting board (2). An end face (3b) of each wire (3a) of the wire group (1) arranged via the mounting plate (4) is opposed to each LED (1a). The mounting plate (4) has annular holes for individual wires (3a). Therefore, the wires (3a) are separated from each other and each light emitting element (1a) is separated and unbound. Therefore, here, a kind of multi-branch incident part is formed. On the other hand, at the end of the light guide (3), the individual wires (3a) are bound together by fusion and / or an adhesive to form a single ring-shaped emission end (3c). This state is the same as that of FIG. 2, and has a ring-shaped space inside. In order to form such a ring-shaped emission part (3c), an insertion hole is formed annularly in front (upstream) of the emission end (3c) as in the case of the element wire mounting plate (4). The fixture (5) may be used. Then, the binding state extends at least to the vicinity of the fixture (5). At this time, the internal ring-shaped space of the ring-shaped emission end (3c) extends at least along the longitudinal direction of the light guide (3), and is preferably formed of an LED group (1) arranged in a ring shape. It extends to a ring-shaped space. In order to form such an extended internal space, a through-hole is cut through each central portion of the mounting board (2) for the LED, the mounting plate (4) for the strand, and the fixture (5). It should be provided.
[0007]
A characteristic of the present invention is that, first, the LED group (1) as a light source is arranged in a ring shape, and the end face (3b) of the element wire (3a) faces each LED (1a). Is formed, while the emission end is located at a point formed in an annular shape.
By doing so, the light from each LED (1a) is focused on the element group (1) while reliably entering the element (3a) facing the LED (1a), and then the ring-shaped emission end (3c) From the light source, there is no problem of uneven light amount when a lamp is used as a light source, and uniform emitted light can be obtained. Further, as a second feature of the present invention, since at least the inside of the light guide (3) is configured to be in a "hollow-out" state, the "hollow-out" portion can be easily used in a lens barrel or the like of an optical microscope. , Whereby a direct attachment from outside of the device is realized. This aspect is illustrated in FIG. 6, as described below.
Examples of the LED (1a) used in the present invention include various types that are commercially available, such as a standard type capable of obtaining a standard light amount and a high-brightness type. In forming the ring-shaped LED group (1), usually, 50 to 100 LEDs (1a) are prepared, the outer diameter is 40 to 80 mm, and the inner diameter is 10 to What is necessary is just to arrange | position on the mounting board (2) in the range of 60 mm and a ring width of 10 mm-30 mm. The material of the LED mounting board (2) is a material having excellent thermal conductivity, for example, a metal, a resin, or a ceramic in order to make the current flowing between the LEDs (1a) the same. desirable.
The optical fiber (3a) used in the present invention may be either glass fiber or plastic fiber (POF) commonly used in the art. The outer diameter of the wire at this time may be in the range of 20 μm to 60 μm, preferably 30 μm to 50 μm from the viewpoint of uniformity of emitted light, strength of the wire itself, and workability. In addition, the wire (3a) facing the LED (1a) is not limited to a single wire, and any number of wires can be selected as long as light from the LED (1a) can be effectively incident. Is preferably used.
Unlike the mounting substrate (2) for LEDs, the material of the mounting plate (4) for fixing the position of the element wire (3a) does not require properties such as thermal conductivity. Is used. Although a rectangular shape is illustrated as the outer shape of the mounting plate (4), this is merely an example, and an arbitrary outer shape is adopted.
In the present invention, the distance between the light emitting surface of the LED (1a) and the end face (3b) of the element wire (3a) is preferably in the range of 10 mm to 30 mm. If this interval is too narrow, the light emitted from the LED (1a) concentrates at the center of the end face (3b) of each element wire (3a), and does not uniformly enter the entire end face, and conversely the interval is wide. If it is too long, a part of the light emitted from the LED (1a) will not easily enter the end face (3b) of the element wire (3a), and as a result, the incidence efficiency will decrease, and the ring-shaped emission section (3c) The illuminance at
With respect to the above-mentioned incidence efficiency, in the present invention, it is preferable to employ a strand (3a) having a numerical aperture of 0.5 or more, that is, a relatively large numerical aperture. By doing so, even when the spread of the light emitted from the LED (1a) is large, it is possible to reliably enter the element wire (3a). That is, since the LED (1a) and the element wire (3a) are coupled in a non-contact state, coupling loss is generally unavoidable with respect to the incident efficiency. However, in the present invention, such coupling loss is significantly reduced. Is done.
Furthermore, in order to ensure this incident efficiency, it is preferable to make the incident end face (3b) of each wire (3a) an inclined face according to the position of the LED (1a).
Specifically, as shown in FIG. 4, the inclination angle of the end face (3b) of the element wire (3a) arranged to face the outer periphery of the LED group (1) arranged in a ring shape is determined. The angle is increased from Q degrees to P degrees as compared with the inclination angle of the end face (3b) of the element wire (3a) arranged to face the inner periphery of the group (1).
The reason for this is as follows.
Generally, when the optical axis of the wire and the optical axis of the LED coincide, it is not necessary to make the end face of the wire, that is, the incident end face, an inclined surface. In this regard, in the present invention, the wire group (3) opposed to the LED group (1) arranged in a ring shape has a ring-shaped emission end (3c) whose outer diameter is reduced by being bound at the ends thereof. Therefore, it is necessary to bend each of the branched wires, and the degree of this bending becomes larger as the wires at the outer peripheral portion become larger. Therefore, in order to make the optical axis of the strand coincide with the optical axis of the LED, a special incident end face is used as described above.
In addition, the light intensity of the LED (1a) may decrease due to variation in light intensity or aging. In order to obtain a more accurate light quantity, as shown in FIG. 5, a light receiving section (6) is provided inside or outside each LED (1a), and a light quantity control section connected to the light receiving section (6) is provided. It is desirable to control the light amount of each LED (1a) by (7). When the light receiving section (6) is provided, a type in which the light receiving section (6) is provided inside the LED (1a) is more preferable because the detection sensitivity is good and the space can be reduced. As the light receiving section (6), various optical sensors such as a light receiving sensor such as a phototransistor and a photodiode can be used. In addition, a known control method such as a feedback control method can be used for the light amount control unit (7).
The above embodiment is an example in which the light emitting end (3c) of the light guide (3) has a ring shape. However, the term “annular” in the present invention does not necessarily indicate only a ring shape (annular shape), but a polygonal shape. The inclusion of an annulus will be readily understood in light of the spirit of the invention.
[0008]
Hereinafter, a specific example in which the light source device of the present invention is mounted on an optical microscope will be described with reference to FIG.
In the figure, (8) is an optical microscope, (8a) is an objective lens, (8b) is a lens barrel (shown in a longitudinal section for convenience), and (8c) is built in the lens barrel (8b). A CCD camera as an imaging device, (8d) is a sample stage, and (9) is an observation target. The light source device shown in FIG. 1 is fitted along the outer periphery of the lens barrel (8b) of such a microscope.
This light source device is created as follows.
80 high-brightness type LEDs (195a) having a wavelength of 695 μm and a light-emitting surface of 2 mm × 2 mm as light sources were arranged on a mounting substrate (2) having an outer diameter of 80 mm in a ring shape. The specifications of the ring-shaped arrangement at this time are an outer diameter of 50 mm, an inner diameter of 20 mm, and a ring width of 30 mm.
Next, 80 bundles (outer diameter 0.5 mm) of 10 strands made of multi-component glass having a strand diameter of 30 μm are prepared as strands (1a), and each of them is provided with 80 insertion holes in a ring shape. The LED (1a) was disposed to face the above-mentioned LED (1a) via the perforated wire attachment plate (4).
On the other hand, at a position 2 mm from the emission end (3c) of the light guide (3), 80 ring-shaped wire insertion holes having an inner diameter of 30 mm, an outer shape of circular shape, a thickness of 0.5 mm, and a diameter of 51 mm were provided. With the fixture (5) made of aluminum and the wires (1a) inserted, the portion reaching the emission end (3c) is adhesive ("TSE-322" (manufactured by Toshiba Silicone Co., Ltd.)). To form a ring-shaped emitting end (3c) having an outer diameter of 55 mm and an inner diameter of 31 mm.
When the object was irradiated with an optical microscope fitted with the above light source device and the light amount and the like were measured, the light amount was sufficient as a conventional lamp (50 W to 100 W). In addition, the variation in light amount (illuminance) was 3% or less, and a high-precision illumination state that was impossible with the conventional lamp was obtained. This variation is calculated as follows. The variation is represented by Rmax / Xa * 100%, where Rmax is the maximum illuminance difference in the illuminance distribution of the effective irradiation section, and Xa is its average.
FIG. 6 shows an example in which the entire light source device of the present invention, that is, the entire light source device (3c) to the LED group (1) is fitted in the lens barrel (8b). If required, therefore, when the size of the ring-shaped arrangement increases with the increase in the number of LEDs used, there is still the possibility of providing this part outside the device.
[0009]
Further, a mode in which the light source device of the present invention is attached to an optical device illumination device or an image illumination device will be described. The former is a typical example of a CCD camera. In this case, the CCD camera is externally fitted to the camera body in parallel with the optical axis. A typical example of the latter is a component mounting inspection apparatus. In this case, the component mounting inspection apparatus may be externally mounted and fixed in the vicinity of the emission section.
[0010]
【The invention's effect】
In the present invention, the LED group (1) as the light source is arranged in a ring shape, and the light-receiving portion used together with the LED group (1a) faces each LED (1a) and constitutes the element wire group. Are divergently arranged in a ring to converge light surely, so that uniform light with sufficient illuminance and no illuminance unevenness can be obtained at the annular emission portion. Moreover, such a light source device is not only easy to cope with a change in specifications such as the amount of light, but also can be fitted from the outside of the optical microscope by using the “hollow portion”. Sex is also greatly improved.
[Brief description of the drawings]
FIG. 1 is a side view showing an example of a light source device of the present invention.
FIG. 2 is a plan view showing an arrangement state of an LED group in FIG. 1;
FIG. 3 is a plan view showing an arrangement state of an optical fiber group in FIG. 1;
FIG. 4 is a partially enlarged view of FIG. 1;
FIG. 5 is a side view showing a preferred embodiment of the light source device of the present invention.
FIG. 6 is a front view showing an example in which the light source device of the present invention is attached to a lens barrel of an optical microscope.
[Explanation of symbols]
1 Light emitting element group (LED group)
1a Light emitting device (LED)
Reference Signs List 2 Light-emitting element mounting substrate 3 Light guide 3a Optical fiber strand 3b Optical fiber strand input end face 3c Light guide emission end face 4 Optical fiber strand group mounting plate 5 Optical fiber strand group fixture 6 Light receiving part 7 Light intensity control unit 8 Optical microscope 8a Objective lens 8b Barrel unit 8c CCD camera 8d Sample table 9 Object to be observed

Claims (5)

A light source comprising a light emitting element group (LED group), and a light guide comprising an optical fiber group for causing light from the light source to enter from one end face and exit from the other end face, and A light source device having requirements a to d.
a. The light emitting element group is arranged in a ring;
b. One end face of each of the optical fibers constituting the optical fiber element group is opposed to and installed on each of the light emitting elements constituting the light emitting element group, and the wires are in a non-bound state to form a multi-branch incident portion. Doing things;
c. The other end face of the optical fiber group forms an emission portion bound in an annular shape;
And d. The inner annular space of the annular light emitting portion extends toward the light emitting element group arranged in the annular shape. The light source device according to claim 1, wherein the optical fiber has a numerical aperture of 0.5 or more. The light source device according to claim 1, wherein an incident end surface of the optical fiber forms an inclined surface corresponding to a position of each of the light emitting elements facing each other. The light source device according to any one of claims 1 to 3, wherein a light receiving unit is provided inside the light emitting element, and the light receiving unit is connected to a light amount control unit that controls the light amount of the element. The light source device according to any one of claims 1 to 4, wherein the light source device is an integrally mounted type that is fitted into the optical microscope device from the outside.

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