JPS6346923B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tabletop lighting device that illuminates the surface of a desk, such as an office desk.

Conventionally, as this type of tabletop lighting device, a device that illuminates a desk surface using a lighting device that has a light source and a reflector inside a main body that has a light emitting aperture is disclosed in Japanese Patent Laid-Open No. 52 This is shown in Publication No.-4681. In this device, a prism-cut refracting plate is provided in the light projection opening to prevent so-called light curtain reflection, in which light from the light source is reflected on the desk surface and causes glare. This device can reduce light curtain reflection, but the refracting plate refracts the light to both sides of the desk, and the reflective plate behind the light source reflects the light from the light source and simply directs it downward. The illuminance distribution on the desk surface is not considered at all. Therefore, the illuminance distribution on the desk surface is non-uniform as shown by the dotted line in FIG. 6, and has the disadvantage that the front end of the illuminated surface, that is, the near side, becomes dark.

On the other hand, as seen in Japanese Unexamined Patent Publication No. 53-123584, it has been proposed to prevent light curtain reflection by providing a polarizing plate in the middle of an elongated light projection aperture. There is. However, the reflectance of light transmitted through a polarizing plate has an incident angle characteristic, and generally, the reflectance is minimum when the incident angle to the illuminated surface is about 65 degrees (Brillusta angle). The smaller the reflectance, the more effective it is to remove light curtain reflection, but in normal desk lighting, light curtain reflection is a problem, and the angle of incidence and reflection on the desk surface is between 25 degrees and 30 degrees.
In this case, the reflectance is equivalent to the case where no polarizing plate is provided. Therefore, it was confirmed that the light curtain reflection caused by this material could hardly be reduced in practice.

The present invention has been made in consideration of the above-mentioned circumstances, and is a tabletop lighting device that can almost uniformly illuminate a desk surface and prevent so-called light curtain reflection, in which light from a light source reflects on the desk surface and causes glare. The purpose is to provide

In the table-top lighting device of the present invention, a louver having a plurality of louver pieces is provided only at an intermediate portion between a reflecting mirror and a light emitting aperture, and the louver is tilted in a forward diagonal direction, and the inclination of the main axis of the reflecting mirror is adjusted to the front side of the louver. The present invention is characterized by comprising a lighting fixture whose inclination is almost the same as that of the lighting fixture, and a support for supporting the lighting fixture on a desk.

Next, details of the present invention will be explained with reference to illustrated embodiments.

In FIG. 1, reference numeral 1 designates an office desk, and 2 designates a lighting fixture that is spaced apart from the desk top surface 3 of the office desk 1 and is disposed at one end of the desk top surface 3 to illuminate the desk top surface 3. The upper ends of two rectangular pillars 4 which are removably installed on the office desk 1 are fixed to the lighting fixture 2, and the lower ends of the pillars 4 are attached to the desk surface of the office desk 1. The lighting fixture 2 is supported at a distance from the desk top surface 3 by fitting into each mounting hole 5 formed at both corners of the rear end and fixing with screws. That is, in this embodiment, the office desk 1
and the pillar 4 constitute a support.

Further, as shown in FIG. 2, the lighting fixture 2 has a light emitting opening 6 on the surface facing the desk surface 3, the lower surface in this embodiment, and if necessary, on the other surface, the upper surface in this embodiment. an elongated instrument body 8 having a light projection opening 7;
A light source 9, such as a straight tube fluorescent lamp, is disposed approximately in the center of the instrument body 8 in parallel with the desk top surface 3, and has at least a straight tube portion 9a extending along the longitudinal direction of the instrument body 8. , the instrument body 8
A reflecting mirror 10 having a substantially parabolic shape and having a focal point at the center O of the light source 9 is spaced apart from the rear of the straight tube portion 9a of the light source 9 and a plurality of louver pieces 11.
a, 11b along the longitudinal direction of the instrument main body 8, and a louver 11 provided only at an intermediate portion of the lower light projection opening 6 of the instrument main body. Transparent prism covers 12 are provided on both sides of the louver 11 of the lower light emitting aperture 6, if necessary.
For example, a milky-white translucent cover 13 is attached to the cover 2 . Also. The light source 9 is removably attached and electrically connected between a pair of left and right lamp sockets 14 fixed within the main body 8. Also,
The reflecting mirror 10 has its upper and lower ends fixed to the main body 8 via support members 15, respectively.

The relationship between the light emitting opening 6, the light source 9, and the reflecting mirror 10 on the surface of the instrument main body 8 facing the desk surface 3, that is, the bottom surface in this embodiment, is as shown in FIGS. 3 and 4. When the vertical angle of the straight line L connecting the front edge 3a of the desk top surface 3 and the center O of the light source 9 is θ, the louver piece 11a of the louver 11 is tilted approximately at θ, and the approximately parabolic reflecting mirror 10 is The main axis 16 is also set at approximately θ.

Here, θ is the height from the desk surface 3 to the center O of the light source 9, that is, the height of the lighting fixture 2, as shown in FIG.
When H is the installation height of , and S is the distance from the perpendicular passing through the center O to the front edge 3a of the desk top surface 3, the angle is tanθ=S/H. In this embodiment, θ=45 degrees due to the relationship between the standard size of a JIS office desk and the standard mounting height of equipment, and considering the diversity of desk 1 sizes and manufacturing variations of reflector 10, θ =45
A range of ±10 degrees is preferred. Furthermore, the extension of the substantially parabolic main axis 16 of the reflecting mirror 10 is a straight line L.
The angle θ of the main shaft 16 is also adjusted to be within the range of θ±10 degrees.

Next, the effect will be explained. Of the light from the light source 9, the light emitted from the intermediate portion of the lower light projection aperture 6 is reflected directly and by the reflecting mirror 10, and is emitted from the light projection aperture 6 through the louver 11. At this time,
Since the inclination of the louver piece 11a is almost equal to the vertical angle θ, the front edge 3 of the desk top surface 3 can be seen by the reflecting mirror 10 without being blocked by the louver piece 11a.
The illuminance of a is increased. At this time, light at a angle of 25 to 35 degrees to the desk surface is blocked, which causes a problem of light curtain reflection.

The light emitted from both sides of the lower light projection opening 6 is reflected directly and by the reflecting mirror 10, passes through the prism cover 12, and is irradiated from the light projection opening 6 on the lower surface of the instrument body 8. At this time, the main axis 16 of the reflecting mirror 10 is at a vertical angle θ of the straight line connecting the front edge of the desk top surface and the center of the light source 9.
Since it is formed at almost the same angle as the desk surface 3
The illuminance in the direction of the front edge 3a can be increased as much as possible. Further, the light transmitted through the prism cover 12 compensates for illumination directly below the louver 11.

Therefore, the illuminance distribution in the longitudinal direction of the middle part of the desk top surface becomes almost uniform over the entire desk top surface, as shown by the solid line in FIG. 6, and the worker's hand side is not darkened.

Then, the reflector 10 of such a lighting equipment,
By adjusting the positional relationship of the louvers 11, it was possible to significantly reduce light curtain reflection. That is, in Fig. 5, H=570mm,
Under standard conditions of desk top width W = 700 mm, louver 1
1 was removed and the position where the light source was specularly reflected on the desk surface 3 was searched. As a result, when the eye is placed at position P1, which is farthest from the desk surface, the specular reflection point is Q1,
Xmax = 350mm from the front edge 3a, the reflection point at the P2 position closest to the eye is Q2, and Xmin = from 3a
It was found that the lamp image was reflected at the 240mm position. The angles of the light sources at this time are θ1 = 29 degrees and θ2 = 36 degrees, respectively.
degree, which is clearly smaller than the inclination angle θ=49 degrees of the main axis 16 of the reflecting mirror 10 and the louver piece 11a in this case. Therefore, by providing the above-mentioned louver 11, the light in the θ1 and θ2 directions is blocked by the louver 11, and the lamp image becomes extremely low in brightness and light curtain reflection is extremely reduced. Note that in the vicinity of the center of the desk surface 3 and in the vicinity directly below the lighting fixture, the light is blocked by the louver 11 disposed in the middle of the light projection opening 6, so the illuminance decreases; It is supplemented by light from the light emitting aperture 6 which is open on both sides and provided with a transparent prism cover 12 as required, so that the degree of symmetry is not deteriorated. Further, since the light from both sides of the louver 11 does not enter the eyes P1 and P2 of the operator, no light curtain reflection occurs.

Note that the louver 11 may be provided only in the area where the operator works, and is desirably formed, for example, in the middle part of the light emitting opening 6 with a length of about 1/3 (for example, 300 to 450 mm).

In the above embodiment, a straight tube fluorescent lamp is used as the light source 9, but the light source 9 is not limited to this, and as long as it has at least a straight tube section 9a, for example, a U-shape or an S-shape having two or more straight tube sections 9a can be used. Other fluorescent lamps may also be used.

Furthermore, in the above embodiment, the light emitting opening 7 was provided on the top surface of the instrument main body 8, and the milky-white translucent cover 13 was attached as a light control member, but the light emitting aperture may not be provided, and the light transmitting cover may also be used to provide light. Other light control members, such as lattice louvers or transparent prism panels, may be installed as long as they diffuse light and reduce glare.

In addition, a transparent plate-like prism cover 12 was attached as a light-transmitting member on both sides of the light projection opening 6 on the lower surface.
This may be omitted, and the light-transmitting member is not limited to the prism cover, and any light-transmitting plate may be attached as long as it does not disrupt light distribution, such as one with a wavy, uneven surface.

In addition, in the tabletop lighting device of the above embodiment, the lighting fixture is fixed by a support consisting of a post and a desk, but a support that can separate the lighting fixture from the desk surface and support it in a general lighting position That's fine.

As described in detail above, the present invention provides a louver only at the intermediate portion between the reflecting mirror and the light emitting aperture, tilts the louver in a forward diagonal direction, and makes the inclination of the main axis of the reflecting mirror almost match the inclination of the louver. This is a tabletop lighting device that is equipped with a lighting fixture and a support that supports the lighting fixture on the desk surface. The illuminance in the direction of the front edge of the top surface can be increased, and the illuminance on the desk surface directly under the lighting fixture is supplemented by the light from the light projection openings on both sides of the louver. In contrast, an extremely uniform illuminance distribution can be obtained. Moreover, the direct light from the intermediate part of the lighting equipment facing the worker and the light reflected by the reflector,
Since it is blocked by the louver, the brightness of the lamp image reflected on the desk surface can be significantly reduced, and light curtain reflection is reduced. Therefore, eye fatigue can be prevented and work efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the table-top lighting device of the present invention, FIG. 2 is a cross-sectional view of the lighting device, and FIG.
The figure is an enlarged cross-sectional view taken along the - line in Figure 2, and Figure 4.
The figure is an enlarged sectional view taken along the line - in FIG. 2, FIG. 5 is a simplified side view for explaining the effect of the present invention, and FIG. 6 is a diagram showing light distribution characteristics of the present invention and the conventional technology. 2...Lighting equipment, 3...Desktop surface, 3a...front edge, 4
... Support column, 6, 7... Light projection opening, 8... Instrument body, 9...
Light source, 9a... Straight tube part, 10... Reflector, O... Center of light source, 11... Louver, L... Straight line connecting the front edge of the desk top surface and the center of the light source, 16... Main axis of the reflector.

Claims (1)

[Scope of Claims] 1. A lighting fixture that is arranged at a distance from a desk top surface and illuminates the desk top surface, and a support that supports the lighting fixture, and the lighting fixture has a light projection opening. an elongated instrument body; a light source disposed within the instrument body and having a straight pipe section extending at least along the longitudinal direction of the instrument body; a substantially parabolic reflecting mirror disposed within the instrument body; and a louver provided only at an intermediate portion of the light emitting opening of the instrument body along the longitudinal direction of the instrument body. 1. A tabletop lighting device, characterized in that the reflecting mirror is tilted in a forward oblique direction and the inclination of the main axis of the reflecting mirror is made to substantially match the inclination of the louver. 2. The tabletop lighting device according to claim 1, wherein the louver is formed in the center of the light emitting opening of the fixture main body, with a length of approximately ⅓ or less of the length along the longitudinal direction. 3. The tabletop lighting according to any one of claims 1 and 2, wherein the fixture main body has another light emitting opening on the other surface opposite to the light emitting opening. Device. 4. The tabletop lighting device according to any one of claims 1 to 3, wherein light-transmitting members are provided on both sides of the louver. 5. The tabletop lighting device according to any one of claims 1 to 4, wherein the light source is a fluorescent lamp.