JP2011076965A - Led light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED light source device for light guide illumination device which can condense efficiently using an illumination LED with a large emission surface and has almost no irradiation unevenness. <P>SOLUTION: An illumination LED in which a large number of LED elements are arranged in plane and made in a package is arranged close to an incident end face of a light guide consisting of a bundle of optical fibers. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an LED light source device suitable for use in a light guide illumination device.

  In general, a light guide illumination device using an LED as a light source, like a light source such as a halogen lamp or a metal halide lamp, collects light with a lens, uses a concave reflecting mirror, or uses both as a light guide. It was incident (for example, Patent Documents 1 to 3).

When the light of the LED element is incident on the light guide using a lens or a concave reflecting mirror, it is necessary to make the light emitting surface of the LED as small as possible in order to increase the light collection efficiency.
In addition, since the light emission of the LED is a natural light emission with almost no directivity, the light emission angle is larger than the angle at which light can be received for condensing by the lens, and therefore the amount of light that cannot be received by the lens is large, and the light collection efficiency is high. bad.

  Furthermore, the light receiving angle (aperture angle) of the light guide is usually larger than the light receiving angle that can be collected by the lens. In general, the LED light spread angle is 120 °, the angle at which the lens can receive light is 60 °, and the light guide has a maximum light reception angle of 120 °.

JP 2003-168309 A JP 2004-247312 A Japanese Unexamined Patent Publication No. 2005-093622

As described above, the conventional light guide illuminating device using an LED as a light source collects light with a lens, a mirror, or the like. Therefore, an illumination LED having a large light emitting surface cannot efficiently collect light and has a small light emitting surface. There is a problem that only very limited LEDs can be used.
In addition, even though the light guide has a sufficiently wide light-receiving angle, if the light is collected by a lens, only light with a narrow light-emitting angle of the LED can be collected. It was.
In addition, when the light is collected by the lens, the condensed light beam becomes a light beam close to parallel light, and even if a light guide with a wide light receiving angle (aperture angle) is used, the emitted light is bright only at the center, and the periphery There was also a problem that irradiation unevenness was large, that is, the amount of light suddenly decreased as it went to the part.

  The present invention has been developed in view of the above-described present situation, and provides an LED light source device for a light guide illumination device that can efficiently collect light using an illumination LED having a large light emitting surface and has almost no irradiation unevenness. The purpose is to do.

Now, as a result of intensive studies to achieve the above-mentioned object, the inventors have completely arranged optical elements such as lenses and mirrors with respect to an illumination LED in which a large number of LED elements are arranged in a plane and packaged. Efficiently receive the emitted light of the LED at the entire light receiving angle (opening angle) of the light guide by installing the light guide fiber's entrance end face as close as possible without using it, making a bundle of optical fiber fibers As a result, the inventors have learned that it is possible to illuminate with bright and uniform emitted light.
The present invention is based on the above findings.

That is, the gist configuration of the present invention is as follows.
1. An LED light source device, characterized in that an illumination LED in which a large number of LED elements are arranged in a package and packaged is disposed close to an incident end face of a light guide made of a bundle of optical fiber fibers.

2. The distance between the illumination LED and the incident end face of the light guide is t, the diameter of the LED element group constituting the illumination LED is L, the diameter of the incident end face of the light guide is F, and the aperture angle (numerical aperture) of the light guide. Is the following equation (1) t ≧ {(F−L) / 2} / tan θ (1)
2. The LED light source device as described in 1 above, wherein the relationship is satisfied.

3. As a method of supplying current to the packaged illumination LED, a unitized section terminal and a printed circuit board cut in accordance with the outline of the illumination LED are used to facilitate replacement and positioning of the LED. The LED light source device according to 1 or 2 above.

According to the LED light source device of the present invention, it is possible to use an illumination LED in which a large number of LED elements are arranged in a plane and packaged without using any optical elements such as lenses and mirrors, and the opening angle of the light guide Since the LED light can be received and emitted over the whole, the light quantity of the whole emitted light can be increased and the brightness of the peripheral portion can be increased as compared with the conventional case.
Further, the LED light source device of the present invention is very compact, and can easily and easily replace and position the LED.

1 is a basic configuration diagram of the present invention. It is the figure which showed the general conventional structure. It is the figure which compared and showed the light quantity distribution characteristic in the case of following this invention and the conventional method. It is the figure which showed the specific Example of this invention. It is LED holding | maintenance structure using a segment terminal. FIG. 6 is an assembly structure diagram of FIG. 5. It is a structural diagram at the time of setting this invention as a general light source device.

Hereinafter, the LED light source device of the present invention will be specifically described with reference to the drawings.
FIG. 1 shows a basic structure of an LED light source device according to the present invention. FIG. 1A is a front view of an illumination LED in which a large number of LED elements are arranged in a plane and packaged. In the figure, reference numeral 1 is an illumination LED, 2 is an individual LED element, and 3 and 4 are currents. This is an introduction terminal. FIG. 1B is a side view showing a state in which the illumination LED 1 and the incident end face 6 of the light guide 5 are arranged close to each other. In addition, (LED1 for illumination-> light guide 5) is comprised with the bundle of optical fiber.

In the present invention, “proximity” when the illumination LED and the incident end face of the light guide are arranged close to each other means that the distance t between the illumination LED and the light guide incident end face is within 3 mm.
Then, there is no lens or mirror between the illumination LED and the incident end face of the light guide as in the prior art, and the irradiation light from the illumination LED is directly received by the incident end face of the light guide. To do.

In the present invention, in order to achieve high light collection efficiency, the distance between the illumination LED 1 and the light guide incident end face 6 is t, the diameter of the LED element group is L, the aperture of the light guide incident end face 6 is F, When the opening angle (numerical aperture) of the light guide is θ,
t ≧ {(F−L) / 2} / tan θ (1)
It is preferable to satisfy this relationship.
Regarding the diameter L of the LED element group, if the LED element group is rectangular as illustrated, the length of the diagonal line is L, and if the LED element group is circular, the diameter is L. That's fine.
Similarly, regarding the aperture F of the light guide incident end face, the length of the diagonal line may be F when the shape is rectangular, and the diameter length may be F when the shape is circular.

FIG. 2 shows a conventional general condensing method. A conventional LED 7 having a small light emitting portion is used as a light source, and the light is condensed by a condensing lens 8 and collected on the incident end face 6 of the light guide 5. I am making it light. In the drawing, reference numeral 9 denotes an emission end face of the light guide 5.
In the above conventional method, as shown in the figure, it is not possible to collect all the emitted light from the LED 7. Further, the light emission angle of the light emitted from the LED 7 is narrowed by the condenser lens 8, that is, the NA (aperture angle) is converted to be small, so that it becomes smaller than the NA of the optical fiber constituting the light guide 5.
As a result, the light emitted from the light guide 5 has a light amount distribution in which only the central portion is bright and the periphery is extremely dark, as indicated by reference numeral 10 in FIG.

FIG. 4 shows the overall configuration of FIG. 1, and shows a case where the lighting LED 1 is installed under a condition that satisfies Expression (1).
In this case, almost all of the light emitted from the LED 7 can be collected, and since no condensing lens is used, the light emission angle of the light emitted from the LED 7 is not narrowed.
As a result, the light quantity distribution when the LED light source device of the present invention is used is a distribution as indicated by reference numeral 11 in FIG. That is, the entire NA of the light guide, that is, the peripheral portion as well as the central portion is brightened, and the absolute light amount (represented by the area surrounded by the curve) is remarkably increased as compared with the conventional case.

FIG. 5 shows a structure in which lighting LEDs are connected by unitized segment terminals 12 regardless of soldering wiring such as electric wires.
In other words, the section terminal 12 is installed vertically, printed and wired so that a current flows through the screw portion 13, and is cut in accordance with the section printed circuit board 14 having a light guide passage hole in the center and the outer shape of the illumination LED. The holding printed circuit board 15 is provided with a current transmission spacer 16 to be connected to the section printed circuit board 14.
By adopting such a structure, the replacement and positioning of the lighting LED 1 become extremely easy.

  FIG. 6 shows the assembled state of FIG. 5, and the section printed board 14 and the holding printed board 15 are connected and fixed by a fixing screw 17. At this time, the segment terminal 12 comes into contact with the current introduction terminals 3 and 4 of the illumination LED 1 and current can be introduced from the power supply section through the current transmission spacer 16 wired by printed wiring.

  FIG. 7 is a structural diagram showing a state in which the light source device according to the present invention having the configuration shown in FIGS. 1 and 5 and 6 is incorporated in a real machine. The holding printed circuit board 15 and the lighting LED 1 are installed on a heat sink 19, and preferably a formula. The base 20 of the light guide 5 is installed so that the incident end face of the light guide 5 is positioned under the conditions satisfying (1). In the figure, reference numeral 21 denotes a power source and 22 denotes an air cooling fan, which can be installed as necessary.

Here, when replacing the lighting LED, after removing the light guide base 20 shown in FIG. 7, the fixing screw 17 is removed, and then the lighting LED fixing screw 18 is removed, so that the lighting LED is replaced. It can be done easily.
In addition, it is possible to accurately position the illumination LED by installing the illumination LED in the cut portion of the holding printed circuit board cut in accordance with the outer shape of the illumination LED.

  The LED light source device of the present invention is not only very compact compared to the prior art, but also can increase the amount of light emitted from the light guide as a whole, and can brighten not only the central part but also the peripheral part, It is particularly effective when applied to light guide lighting devices.

1 LED for lighting
2 LED element group 3, 4 Current introduction terminal 5 Light guide 6 Light guide incident end face 7 Conventional LED
8 Condenser lens 9 Light guide exit end face
10 Conventional light distribution
11 Light distribution of the method of the present invention
12 Intercept terminal
13 Printed wiring
14 Section printed circuit board
15 Holding PCB
16 Current transfer spacer
17 Fixing screw
18 LED fixing screw for lighting
19 Heat sink
20 Light guide base
21 Power supply
22 Air cooling fan

Claims (3)

  An LED light source device, characterized in that an illumination LED in which a large number of LED elements are arranged in a package and packaged is disposed close to an incident end face of a light guide made of a bundle of optical fiber fibers. The distance between the illumination LED and the incident end face of the light guide is t, the diameter of the LED element group constituting the illumination LED is L, the aperture of the incident end face of the light guide is F, and the aperture angle (numerical aperture) of the light guide. Is the following equation (1) t ≧ {(F−L) / 2} / tan θ (1)
The LED light source device according to claim 1, wherein the relationship is satisfied.   As a method of supplying current to the packaged illumination LED, a unitized section terminal and a printed circuit board cut in accordance with the outline of the illumination LED are used to facilitate replacement and positioning of the LED. The LED light source device according to claim 1 or 2.

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