JPS6258082B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention uses a straight tube light source lamp and an inverted boat bottom type reflector as a composite reflector, and the first purpose is to distribute soft light as desired without wasting it. The second objective is to reduce the size of the reflector and the overall size of the device.

In general, lighting equipment for drafting tables or desk lighting stands are required to have light distribution that effectively illuminates the front, and for this reason, various improvements have been made to the curved surface of the reflector. In addition, this type of reflector does not cause eye fatigue,
Soft light is required, and it is preferable to reduce the width of the front and back of the reflector so that the entire device can be made smaller.

By the way, in the above-mentioned light distribution, if a specular reflection plate is used, it is easy to design the light to be distributed in a desired direction, but this is not preferable because the light is hard. On the other hand, it is preferable to use a diffuse reflection plate simply to soften the light, but this makes it difficult to obtain the required effective light distribution. Furthermore, if the front and rear widths of the reflector are simply made smaller, the light source lamp will be brought closer to the reflector, and a greater proportion of the light reflected by the reflector will be blocked by the light source lamp, resulting in poor illumination efficiency.

To explain the illumination efficiency of the reflector whose entire surface is a mirror surface, in FIG. Considering the reflection of light that enters the front reflecting plate 2a from the light source lamp 1 at the point O, the light emitted from the M-N plane of the light source lamp 1 enters the point O. The light incident from the M point to the O point (indicated by the dotted line) is reflected in the R direction (indicated by the dotted line) at a reflection angle equal to the incident angle. Further, the incident light from point N to point O is similarly reflected in the direction of P, and diagonally downward at point P of the rear reflecting plate 2b.
In other words, the incident light from the light source lamp 1 at point O will be reflected in each direction within the range included in ∠POR, but the light reflected in the range included in ∠MOR will be reflected by the light source lamp 1. Since light is blocked and lost, the only thing that can be used as effective light is ∠
This light is reflected in the range included in POQ, and these reflected lights are reflected downward again at each point on the reflection surface PQ of the reflection plate 2b.

When a specular reflector is used in this way, light loss occurs, and in order to reduce this loss, the distance between the light source lamp 1 and the reflector 2 must be increased, which also poses a problem in terms of miniaturization.

The present invention takes these problems into consideration and is a lighting fixture that enables effective light distribution and efficient illumination even with a small reflector.

The feature of the present invention lies in the configuration of the reflector in the shape of an inverted boat bottom, that is, as shown in FIG.
The front side of the reflector 3 is a diffuse reflector 3a, and the rear side is a specular reflector 3b, with a line passing through the approximate center of the opening side and the approximate center of the bottom side as a boundary, that is, a composite reflector. . The diffuse reflection plate 3a has a front and back width smaller than that of the specular reflection plate 3b, so the front and rear width of the entire reflection plate 3 is smaller than that of the specular reflection plate 3b.
The reflector plate 3 is configured to be smaller by the smaller a.
The depth and front and rear width of the opening side are almost the same, and in the reflector 3 of the straight tube light source lamp 4, the position closer to the diffuse reflector 3a by the width of the diffuse reflector 3a is reduced. It is located in

The light source lamp and the reflector in the lighting fixture of the present invention are constructed as described above, and first, the light source lamp 4 at the point O of the diffuse reflector 3a, as in the case described above.
To explain the reflection state of the incident light from the light source lamp 4, the light incident from the M point to the O point of the light source lamp 4 has a reflection angle equal to the incident angle like a mirror surface, although it depends on the finishing condition of the reflecting surface. Rather than being strongly reflected in only one direction, the light is diffused and reflected in each direction as shown by the dotted lines. Further, the incident light from the N point to the O point is similarly diffusely reflected in each direction as shown by the solid line.

Therefore, the incident light from the light source lamp 4 to point O will be reflected in almost every direction on the diffuse reflection plate 3a, and among these, the light in the direction included in ∠MON is blocked by the light source lamp 4. However, all the reflected light upward from the MO is effectively reflected downward again by the specular reflector 3b on the rear side, and the reflected light downward from the NO is directly irradiated downward into the equipment. , both become effective light.

As described above, the reflector according to the present invention can effectively utilize light, and is particularly effective when the reflector is designed to be smaller than the size of the light source lamp. Furthermore, since the rear side is a specular reflector, light distribution toward the front can be improved. For example, as shown in light distribution characteristic A in Figure 3, its light distribution is better in the front direction ( It has the advantage of widening the spread of light in the front direction (front direction) and providing softer illumination.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a reflector according to an embodiment of the present invention, FIG. 2 is a block diagram of a fully specular reflector, and FIG. 3 is a light distribution characteristic diagram. 3...Reflector, 3a...Diffuse reflector, 3b...
Specular reflector, 4...Light source lamp.

Claims (1)

[Claims] 1.Equipped with a straight tube type light source lamp and an inverted boat bottom type reflector, in a cross section perpendicular to the tube axis of the light source lamp, the reflector passes through the approximate center of the opening side and the approximate center of the bottom side of the reflector. It is a composite reflector with a diffuse reflector on the front side and a specular reflector on the rear side with the line as a boundary, and the diffuse reflector has a front and back width smaller than that of the specular reflector, and the light source A stand-type lighting device characterized in that the lamp is arranged close to the diffuser reflecting plate, and the depth of the reflecting plate and the front-rear width on the opening side are approximately the same.