JP3668359B2 - Lighting - Google Patents

Description

[0001]
BACKGROUND 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 accent illumination that is turned on in a store or the like, or illumination for document exposure such as FAX.
[0002]
[Prior art]
Conventionally, halogen light bulbs are often used as light sources for general illumination and document exposure of optical equipment. Halogen bulbs have excellent luminous efficiency and can emit a large amount of light. On the other hand, when used as a light source for document exposure, the vibration during movement of the lamp house is transmitted to the halogen bulb and the filament There is a problem that it is easy to cut. Furthermore, a light source with higher luminous efficiency is demanded from the demand for power saving.
[0003]
An LED is known as a light source with extremely low power consumption. The LED can obtain sufficient luminance with a low voltage of about several volts and a low power of about 10 mW. In addition, the luminance can be easily controlled by the current, and the advantages are that the response speed is fast, the light emission is stable, and the lifetime is long. For this reason, conventionally, LEDs are often used as display lamps for electronic devices that use batteries as a power source or display elements for matrix display devices.
[0004]
[Problems to be solved by the invention]
Recently, a white LED with high luminous intensity has been developed, and the LED is attracting attention as a new light source for accent lighting that is turned on in a store or the like. As an example of an illuminating lamp using LEDs, Japanese Utility Model Laid-Open No. 1-70364 can be cited.
[0005]
In an illuminating lamp using an LED, since the intensity of light is low with one LED, a plurality of LEDs are mounted on a substrate with their optical axes parallel to serve as a light source. And since the LED has a strong directivity of light and light is emitted only within 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 increases.
[0006]
In addition, as described above, since the LED has a strong directivity of light, when a plurality of LEDs are mounted on a substrate with their optical axes parallel to be used as a light source, the influence of a non-light emitting portion existing between adjacent LEDs is affected. Therefore, there is a problem that unevenness in illuminance in which a bright part and a dark part are mixed in the illumination area occurs.
[0007]
Therefore, the present invention has an object to provide an illuminating lamp that has little unevenness in illuminance and does not require a large number of LEDs even when illuminating a wide area and consumes very little power.
[0008]
[Means for Solving the Problems]
In order to achieve such an object, the invention of claim 1 includes a concave reflecting mirror, a light emitting diode for direct illumination whose optical axis faces the opening of the concave reflecting mirror, and a plane substantially perpendicular to the optical axis of the concave reflecting mirror. A plurality of reflective illumination light emitting diodes arranged in an annular shape with the optical axis directed toward the reflective surface of the concave reflecting mirror, and a single substrate on which the direct illumination light emitting diode and the reflective illumination light emitting diode are held The substrate is attached to a resin mold disposed at the base end of the concave reflecting mirror.
[0009]
Further, the invention of claim 2 is the same as the light emitting diode for direct illumination in which a plurality of hook-shaped reflectors are arranged in the longitudinal direction of the hook-shaped reflector and the optical axis is directed to the opening of the hook-shaped reflector. A plurality of reflective illumination light-emitting diodes arranged in the longitudinal direction of the bowl-shaped reflector and having an optical axis directed to the reflection surface of the bowl-shaped reflector , a direct illumination light-emitting diode, and a reflective illumination light-emitting diode are held 1 The substrate is attached to a resin mold disposed at the base end of the bottom of the bowl-shaped reflecting mirror.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described below with reference to the drawings. 1 and 2 show an embodiment of the invention of claim 1 in which a concave reflecting mirror 11 such as an elliptical mirror or a parabolic mirror is used as a reflecting mirror. The concave reflecting mirror 11 is dimple processed on its reflecting surface and has a function of diffusing reflected light, but is attached to a ceramic base 20 at its base end. A base 21 is attached to the tail end side of the base 20.
[0011]
A resin mold 40 is disposed from the base end portion of the concave reflecting mirror 11 into the base 20. In the resin mold 40, a diode bridge 51 and a step-down resistor 52 for rectifying commercial power of AC 100V are disposed. A substrate 41 is attached to the top surface of the resin mold 40, and a direct illumination light emitting diode 31 and a reflective illumination light emitting diode 32 described below are held on the substrate 41. The light emitting diodes 31 and 32 are, for example, 13 LEDs as shown in the figure, and 13 LEDs and a step-down resistor 52 are connected in series and 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.
[0012]
The light emitting diodes 31 and 32 have a DC forward current of 25 mA, a DC forward voltage of 3.6 V, a power consumption of 0.09 W, a color temperature of 8000 K, a chromaticity coordinate of x = 0.29, and y = 0.30. High output white LED. Therefore, even if 13 LEDs are used, the power consumption is 1.17 W.
[0013]
The direct illumination light-emitting diode 31 is composed of, for example, five LEDs and is attached to the substrate 41. Each direct illumination light-emitting diode 31 is attached in the vicinity of the optical axis X of the concave reflecting mirror 11. In addition, the optical axis of the direct illumination light emitting diode 31 faces the opening of the concave reflecting mirror 11. Accordingly, the light from the direct illumination light emitting diode 31 directly illuminates the vicinity of the center of the illumination area without being reflected by the concave reflecting mirror 11.
In the illustrated example, the optical axis of the direct illumination light-emitting diode 31 and the optical axis X of the concave reflecting mirror 11 are parallel, but they are not necessarily parallel. The illumination area may be directly illuminated without being reflected by the concave reflecting mirror 11.
[0014]
On the other hand, the reflective illumination light emitting diode 32 is composed of, for example, 8 LEDs, and is arranged in an annular shape around the outer periphery of the direct illumination light emitting diode 31 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 and the optical axis of the concave reflecting mirror 11 are substantially orthogonal. For this reason, the light of the light emitting diode 32 is reflected in a state of being diffused by the concave reflecting mirror 11, and each reflected light irradiates 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 or the surface state of the reflecting surface.
If the annular light emitting diodes 32 for reflective illumination are arranged in a double or triple multiple along the optical axis of the concave reflecting mirror 11, the power consumption is slightly increased, but a wider range can be illuminated brightly. it can.
[0015]
Thus, in 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 is diffused by the concave reflecting mirror 11 and is constant. Since the illumination area is irradiated with a spread at the beam angle, the illuminance is high near the center of the illumination area, and the illuminance decreases in a mountain shape as the distance from the center decreases. In addition, although the LED having strong directivity of light is used as the light source, the light reflected by the concave reflecting mirror 11 of the light emitting diode 32 for reflection illumination and the light of the light emitting diode 31 for direct illumination are combined to produce illuminance. Unevenness is extremely reduced. Therefore, such an illuminating lamp is suitable for accent lighting that is lit in a store or the like.
[0016]
FIG. 5 shows a light distribution characteristic curve when the beam angle of such an illuminating lamp is within a range of 60 °. As can be seen, the illuminance at the center is the highest, and as the distance from the center increases, the illuminance gradually and gently decreases, indicating that there is little illuminance unevenness. Further, when the illuminance at the center is 100%, the illuminance at the position where the beam angle is 60 ° is about 55%.
[0017]
Next, based on FIG. 3 and FIG. 4, Embodiment of invention of Claim 2 is shown. The reflecting mirror to be used is a bowl-shaped reflecting mirror 12 having a cross-sectional shape of an ellipse or a parabola, and elongated horizontally. A resin mold 40 is disposed at the bottom of the bowl-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 the base 20 on the back surface of the bowl-shaped reflecting mirror 12.
[0018]
On the substrate 41, 18 light emitting diodes 31 for direct illumination are arranged, for example, in two rows near the center line in the longitudinal direction. The optical axis of the direct illumination light emitting diode 31 faces the opening of the bowl-shaped reflecting mirror 12. Therefore, the light of the direct illumination light emitting diode 31 directly illuminates the vicinity of the center line in the longitudinal direction of the rectangular illumination region without being reflected by the bowl-shaped reflecting mirror 12. In the illustrated example, the optical axis of the direct illumination light emitting diode 31 and the axis optical axis of the bowl-shaped reflector 12 are parallel, but they are not necessarily parallel. In short, the light is reflected by the bowl-shaped reflector 12. The light from the light emitting diode 31 for direct illumination may directly illuminate the illumination area.
[0019]
On the other hand, the light-emitting diodes 32 for reflective illumination are also arranged in, for example, two rows on the substrate 41 in the longitudinal direction, but the optical axis faces the reflecting surface of the bowl-shaped reflecting mirror 12. Accordingly, the light-emitting diode 32 for reflected illumination is reflected in a state of being diffused by the bowl-shaped reflecting mirror 12, and each reflected light irradiates the illumination area with a spread in the width direction.
Note that the arrangement method of the direct illumination light emitting diodes 31 and the reflective illumination light emitting diodes 32 is not limited to the illustrated example, and it may be arranged in one or more rows along the longitudinal direction of the substrate 41. The light emitting diode 31 needs to be near or substantially parallel to the center line in the longitudinal direction.
[0020]
Thus, in the invention of claim 2, the direct illumination light emitting diode 31 directly illuminates the vicinity of the center in the longitudinal direction of the rectangular illumination region, and the reflective illumination light emitting diode 32 is diffused by the bowl-shaped reflector 12. In this state, the illumination area is irradiated with a spread in the width direction, so that the illumination intensity in the vicinity of the center line in the longitudinal direction of the illumination area is high, and the illumination intensity decreases as the distance from the longitudinal center line increases. The light reflected by the bowl-shaped reflecting mirror 12 of the diode 32 and the light of the direct illumination light emitting diode 31 are combined, and the illuminance along the longitudinal direction has a substantially uniform illuminance distribution with little illuminance unevenness.
[0021]
FIG. 6 shows the light distribution characteristics in the longitudinal direction of such an illuminating lamp. As can be seen, the variation in relative illuminance is within ± 5% excluding both ends, and there is little illuminance unevenness in the longitudinal direction even though an LED with high light directivity is used as the light source. Therefore, the illumination area is suitable for an illumination lamp for exposing a document with a long and narrow illumination area. In addition, when used as an illumination lamp for document exposure, the LED is resistant to vibration even when vibration is generated when a lamp with a built-in illumination lamp travels. The lighting problem can be solved.
[0022]
【The invention's effect】
As described above, the illuminating lamp according to the present invention uses a concave reflecting mirror or a bowl-shaped reflecting mirror, and is reflected by the reflecting mirror and illuminates the illumination area with a wide area, and the reflecting illumination light emitting diode. A 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 reflection is held on one substrate, and this substrate is held at the base end of the concave reflector or the bowl-shaped reflector It is attached to a resin mold placed at the bottom of the lamp, and the light from the light-emitting diodes for reflection illumination and direct light-emitting diodes is synthesized. Therefore, it is possible to provide an illuminating lamp with extremely low power consumption.
[Brief description of the drawings]
FIG. 1 is a side view in which a part of an embodiment of the invention of claim 1 is cut away;
FIG. 2 is a front view of an embodiment of the invention of claim 1;
FIG. 3 is a side view of an embodiment of the invention of claim 2;
4 is a front view of an embodiment of the invention of claim 2; FIG.
FIG. 5 is a light distribution characteristic diagram of the invention of claim 1;
6 is a light distribution characteristic diagram of the invention of claim 2. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Concave reflecting mirror 12 Spear-shaped reflecting mirror 20 Base 21 Base 22 Lead wire 31 Light emitting diode 32 for direct illumination Light emitting diode 40 for reflected illumination Resin mold 41 Board | substrate 51 Diode bridge 52 Resistance for step-down

Claims (2)

A concave reflecting mirror, a light emitting diode for direct illumination whose optical axis is directed to the opening of the concave reflecting mirror, and an optical axis directed to the reflecting surface of the concave reflecting mirror on a plane substantially perpendicular to the optical axis of the concave reflecting mirror A plurality of reflective illumination light emitting diodes, and a single substrate on which the direct illumination light emitting diode and the reflective illumination light emitting diode are held,
The said lamp | ramp is attached to the resin mold arrange | positioned at the base end part of a concave reflective mirror, The illuminating lamp characterized by the above-mentioned . A plurality of hook-shaped reflectors, and a plurality of light emitting diodes for direct illumination that are arranged in the longitudinal direction of the bowl-shaped reflector and whose optical axis faces the opening of the bowl-shaped reflector, and also in the longitudinal direction of the bowl-shaped reflector A plurality of light emitting diodes for reflection illumination whose optical axis is directed to the reflecting surface of the bowl-shaped reflector , and a single substrate on which the light emitting diode for direct illumination and the light emitting diode for reflection illumination are held;
The said board | substrate is attached to the resin mold arrange | positioned at the back bottom part of a bowl-shaped reflective mirror, The illuminating lamp characterized by the above-mentioned .

Images