JPH1117228A - Lighting - Google Patents

Abstract

(57) [Problem] To provide an illuminating lamp which has less illuminance non-uniformity and does not need to increase the number of light emitting diodes even when illuminating a wide area, and has extremely low power consumption. A concave reflecting mirror or a gutter-like reflecting mirror is provided.
The light axis is substantially parallel to the optical axis of the reflecting mirror, and the light emitting diode 31 for direct illumination directly illuminates the vicinity of the center of the illumination area or the vicinity of the center line in the longitudinal direction, and the optical axis faces the reflecting surface of the reflecting mirror. The light-emitting diode 32 is disposed, and the reflected light illuminates the illumination area with a spread.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating lamp using a light emitting diode (LED) as a light source, which is used for lighting an accent in a store or the like, or for exposing a document such as a facsimile. is there.

[0002]

2. Description of the Related Art Conventionally, a halogen bulb is often used as a light source for general illumination or for exposing a document of an optical apparatus. Halogen bulbs have excellent luminous efficiency and can emit light of high intensity.On the other hand, when used as a light source for exposing a document, vibrations during movement of the lamp house are transmitted to the halogen bulb and filament There is a problem that is easy to cut. Further, from the demand for power saving, a light source having more excellent luminous efficiency has been demanded.

As a light source with extremely low power consumption, LE
D is known. The LED has a low voltage of several volts and 10
Sufficient luminance can be obtained with a small power of about mW. In addition, there are advantages that the luminance can be easily controlled by the current, the response speed is fast, the light emission is stable, and the life is long. Conventionally, therefore, LEDs have often been used as display lamps for electronic devices or the like powered by batteries or as display elements for matrix display devices.

[0004]

Recently, a white LED having a high luminous intensity has been developed, and as a new light source for accent lighting etc. which is lit in a store or the like.
The ED is paying attention. As an example of an illumination lamp using an LED, Japanese Utility Model Laid-Open No. 1-70364 can be cited.

In an illumination lamp using LEDs, since the light intensity of one LED is low, a plurality of LEDs are used.
The light axis is attached to the substrate with its optical axis parallel to form a light source. Since LEDs have strong directivity of light and emit light only in a range of about 60 ° around the optical axis, when illuminating a wide area, a large number of LEDs are required, and the price increases. There is a problem that power consumption is increased.

As described above, since LEDs have high light directivity, when a plurality of LEDs are mounted on a substrate with their optical axes parallel to each other to form a light source, non-light-emitting elements existing between adjacent LEDs are used. Due to the influence of the parts, there is a problem that illuminance unevenness occurs in which a bright part and a dark part are mixed in the illumination area.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an illuminating lamp which has less illuminance unevenness and does not need to increase the number of LEDs even when illuminating a wide area, and consumes very little power.

[0008]

In order to achieve the above object, the invention of claim 1 comprises a concave reflecting mirror, a light emitting diode for direct illumination whose optical axis is directed to an opening of the concave reflecting mirror, and a concave reflecting mirror. On a plane substantially perpendicular to the optical axis of the mirror, it is constituted by a plurality of light-emitting diodes for reflective illumination arranged in an annular shape with the optical axis facing the reflecting surface of the concave reflecting mirror.

Further, the invention according to claim 2 provides a gutter-shaped reflecting mirror,
A plurality of light emitting diodes for direct illumination, which are arranged in the longitudinal direction of the gutter-shaped reflecting mirror and whose optical axis is directed to the opening of the gutter-shaped reflecting mirror,
Similarly, a plurality of light-emitting diodes are arranged in the longitudinal direction of the gutter-shaped reflecting mirror, and the optical axis is directed to the reflecting surface of the gutter-shaped reflecting mirror.

[0010]

Embodiments of the present invention will be specifically described below with reference to the drawings. 1 and 2 show a concave reflecting mirror 1 which is an elliptical mirror or a parabolic mirror as a reflecting mirror.
1 shows an embodiment of the invention of claim 1 in which the first embodiment is used. The concave reflecting mirror 11 has its reflecting surface subjected to dimple processing,
It has a function of diffusing the reflected light, and is attached to a base 20 made of ceramic at its base end. And
A base 21 is attached to the tail end side of the base 20.

A resin mold 40 is disposed from the base end of the concave reflecting mirror 11 to the inside of the base 20. In the resin mold 40, a diode bridge 51 for rectifying a commercial power supply of AC 100V and a step-down resistor 52 are arranged. A substrate 41 is mounted on the top surface of the resin mold 40, and a light emitting diode 31 for direct illumination and a light emitting diode 32 for reflected illumination described below are held on the substrate 41. The light emitting diodes 31 and 32 include, for example, 13 LEDs as shown in the figure, and the 13 LEDs and the step-down resistor 52 are connected in series and are electrically connected to the output side of the diode bridge 51. . The input side of the diode bridge 51 is connected to the base 21.

The light emitting diodes 31 and 32 have a DC forward current of 25 mA, a DC forward voltage of 3.6 V, and a power consumption of 0.0.
9W, color temperature 8000K, chromaticity coordinates x = 0.29,
y = 0.30, which is a high-output white LED. Therefore, even if 13 LEDs are used, the power consumption is 1.17.
W.

The light emitting diode 31 for direct illumination comprises, for example, five LEDs and is mounted on the substrate 41. Each light emitting diode 31 for direct illumination is located near the optical axis X of the concave reflecting mirror 11. The light axis of the light emitting diode 31 for direct illumination is attached, and faces the opening of the concave reflecting mirror 11. Therefore, the light of the light emitting diode 31 for direct illumination directly illuminates the vicinity of the center of the illumination area without being reflected by the concave reflecting mirror 11. In the example shown,
Optical axis of light emitting diode 31 for direct illumination and concave reflecting mirror 11
Are parallel to each other, but they need not always be parallel. The point is that if the light from the light emitting diode 31 for direct illumination is not reflected by the concave reflecting mirror 11 and the illumination area is directly illuminated. Good.

On the other hand, the light emitting diode 32 for reflected illumination is
For example, it is composed of eight LEDs, and is arranged in a circular shape around the outer periphery of the light emitting diode 31 for direct illumination on a plane substantially orthogonal to the optical axis of the concave reflecting mirror 11, that is, the optical axis of the light emitting diode 32 The optical axes of the concave reflecting mirror 11 are substantially orthogonal. Therefore, the light of the light emitting diode 32 is
The light is reflected by the concave reflecting mirror 11 while being diffused, and each reflected light illuminates the illumination area with a certain beam angle and spread. This beam angle can be adjusted by changing the curvature of the concave reflecting mirror 11 and the surface condition of the reflecting surface. In addition, if the annular reflective light emitting diode 32 is arranged in a double or triple multiplex along the optical axis of the concave reflecting mirror 11, power consumption is slightly increased, but a wider range can be brightly illuminated. it can.

Thus, according to the first aspect of the present invention,
The direct illumination light emitting diode 31 directly illuminates the vicinity of the center of the illumination area, and the reflected illumination light emitting diode 32 illuminates the illumination area with a certain beam angle and spread while being diffused by the concave reflecting mirror 11. Therefore, the illuminance is high near the center of the illumination area, and the illuminance decreases as the distance from the center increases. LE with strong light directivity
Even though D is used as the light source, the light reflected by the concave reflecting mirror 11 of the light-emitting diode 32 for reflected illumination and the light from the light-emitting diode 31 for direct illumination are combined, and illuminance unevenness is extremely reduced. Therefore, such an illumination lamp is suitable for accent lighting or the like that is lit in a store or the like.

FIG. 5 shows a light distribution characteristic curve when the beam angle of such an illumination lamp is in the range of 60 °. As can be seen from this, the illuminance at the center is the highest, and the illuminance gradually and gently decreases as the distance from the center increases, indicating that the illuminance unevenness is small. When the illuminance at the center is 100%, the illuminance at the position where the beam angle is 60 ° is about 5%.
5%.

Next, an embodiment of the present invention will be described with reference to FIGS. The reflecting mirror to be used is an elliptical or parabolic cross-sectional shape, and a gutter-like reflecting mirror 12 which is long and narrow in the horizontal direction. A resin mold 40 is arranged at the bottom of the gutter-shaped reflecting mirror 12, and a rectangular substrate 41 is attached to the top surface of the resin mold 40. A pair of lead wires 22 extends from a base 20 on the back surface of the gutter-shaped reflecting mirror 12.

On the substrate 41, 18 light-emitting diodes 31 for direct illumination are arranged in the vicinity of the center line in the longitudinal direction, for example, in two rows. And the light emitting diode 31 for direct illumination
Is directed to the opening of the gutter-shaped reflecting mirror 12. Therefore,
The light from the light emitting diode 31 for direct illumination is
Directly illuminates the vicinity of the center line in the longitudinal direction of the rectangular illumination area without being reflected by the light source. In the illustrated example, the optical axis of the light emitting diode 31 for direct illumination and the axial optical axis of the gutter-shaped reflecting mirror 12 are parallel, but they are not necessarily parallel. Instead, the light of the direct illumination light emitting diode 31 may directly illuminate the illumination area.

On the other hand, the light emitting diode 32 for reflected illumination is also
For example, two rows are arranged on the substrate 41 in the longitudinal direction, and the optical axis faces the reflecting surface of the gutter-shaped reflecting mirror 12. Therefore, the light-emitting diode 32 for reflected illumination is provided with the gutter-shaped reflecting mirror 12.
Are reflected in a diffused state, and each reflected light illuminates the illumination area with a spread in the width direction. The light emitting diode 31 for direct illumination and the light emitting diode 3 for reflected illumination
2 is not limited to the example shown in FIG.
May be arranged in one or two or more rows along the longitudinal direction. However, the direct-lighting light emitting diodes 31 need to be near or substantially parallel to the longitudinal center line.

Thus, in the invention of claim 2,
The direct illumination light emitting diode 31 directly illuminates the vicinity of the center of the rectangular illumination area in the longitudinal direction, and the reflected illumination light emitting diode 32 is scattered by the gutter-shaped reflecting mirror 12 and illuminates in the width direction. Since the area is irradiated, the illuminance is high near the center line in the longitudinal direction of the illumination area, and the illuminance decreases as the distance from the center line in the longitudinal direction increases. The light of the light emitting diode 31 for direct illumination is synthesized, and the illuminance along the longitudinal direction has almost uniform illuminance distribution with little illuminance unevenness.

FIG. 6 shows the light distribution characteristics in the longitudinal direction of such an illumination lamp. As can be seen from this, the variation in relative illuminance is within ± 5% except for both ends, and the illuminance non-uniformity in the longitudinal direction is small even though an LED having high light directivity is used as a light source. Therefore, it is suitable for an illumination lamp for exposing a document having a narrow illumination area. In addition, when used as an illumination light for exposing a document, the LED is resistant to vibration even when vibration is applied when a lamp with a built-in illumination light travels,
As in the related art, it is possible to eliminate the problem that the filament of the incandescent lamp is not turned on due to the disconnection.

[0022]

As described above, the illuminating lamp of the present invention uses a concave reflecting mirror or a trough-shaped reflecting mirror, and reflects light from the reflecting mirror to illuminate an illumination area with a spread. Is combined with the light of the light emitting diode for direct illumination that illuminates the vicinity of the center of the illumination area or the vicinity of the center line in the longitudinal direction without being reflected by the reflecting mirror, thereby illuminating a wide area with less illuminance unevenness. Also in this case, it is not necessary to increase the number of LEDs so much, and an illuminating lamp with extremely low power consumption can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of an embodiment of the present invention.

FIG. 2 is a front view of the embodiment of the first invention.

FIG. 3 is a side view of an embodiment of the invention according to claim 2;

FIG. 4 is a front view of the embodiment of the second invention.

FIG. 5 is a light distribution characteristic diagram according to the first embodiment.

FIG. 6 is a light distribution characteristic diagram according to the second aspect of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Concave reflecting mirror 12 Gutter-shaped reflecting mirror 20 Base 21 Base 22 Lead wire 31 Light emitting diode for direct lighting 32 Light emitting diode for reflecting lighting 40 Resin mold 41 Substrate 51 Diode bridge 52 Step-down resistance

Continuing from the front page (72) Inventor Kazuya Kurokawa 860-22 Nishiharu, Fukusaki-cho, Kanzaki-gun, Hyogo Prefecture Inside Ushio Lighting Co., Ltd. (72) Inventor Seiji Kawai 4-4-2 Kamiosaki 4 Shinagawa-ku, Tokyo Metro Inside Electric Industry Co., Ltd.

Claims (2)

[Claims] 1. A concave reflecting mirror, a light emitting diode for direct illumination having an optical axis directed to an opening of the concave reflecting mirror, and a concave reflecting mirror on a plane substantially perpendicular to the optical axis of the concave reflecting mirror. An illumination lamp comprising a plurality of light-emitting diodes for reflection illumination arranged annularly toward the reflection surface of (1). 2. A gutter-shaped reflecting mirror, a plurality of light-emitting diodes for direct illumination arranged in the longitudinal direction of the gutter-shaped reflecting mirror and having an optical axis directed to an opening of the gutter-shaped reflecting mirror. An illumination lamp comprising a plurality of light emitting diodes for reflection illumination, which are arranged in the longitudinal direction of the mirror and whose optical axis is directed to the reflection surface of the gutter-shaped reflection mirror.