JPH0322302A - Lighting device - Google Patents

Abstract

PURPOSE:To obtain a proper luminance distribution at any time when an upper lamp or a lower lamp is lighted, and to suppress a decrease in efficiency when two lamps are lighted by setting the focus of the reflector of a lighting device within a predetermined range so as to cut the shading angle at 30 degrees while narrowing the opening width of the lighting device. CONSTITUTION:A focus K of reflectors 7, 8 is set at the middle point of the center H1 of an upper lamp 3 and the center of the lower lamp 5, and the reflectors 7, 8 are set with their parabolic axis rotated by 30 degrees from the vertical axis. Luminous flux of both reflected light and direct light below the shading angle of 30 degrees are cut during the lower lamp is lighted, and luminous flux of both reflected light and direct light below 50 degrees are cut during the upper lamp is lighted. Thus, a proper luminance distribution is obtained when the upper or the lower lamp is lighted, and the decrease in the efficiency is suppressed when both lamps are lighted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to lighting equipment, and particularly to lighting equipment that can improve illumination uniformity and optimize the shape of light distribution while narrowing the opening width of the equipment. Regarding equipment.

[Prior Art] Conventionally, there have been lighting fixtures that are provided with two lamps at the top and bottom, and the two upper and lower lamps or one lower lamp is turned on.

[Problems to be Solved by the Invention] Incidentally, in order to suppress direct reflection from the CRT screen of various OA equipment, it is desirable that the shading angle of the lighting equipment be 30 degrees or less. The aperture width of the device becomes wide (for example, 300 mm) in order to cut the light beam whose direction (angle from the horizontal) is less than 30 degrees. However, when installing it on the ceiling together with a single-lamp lighting fixture (for example, opening width is 150 mm), there are problems such as holes of different widths needing to be drilled in the ceiling, making uniformity impossible. Ta.

On the other hand, conventional products have the disadvantage that when the opening width of the lighting fixture is narrowed, the shape of the light distribution deteriorates and the quality of the lighting fixture deteriorates. In addition, with conventional products, it was not possible to use the product by lighting only the upper lamp.

In view of the above-mentioned problems with the conventional type, the present invention makes it possible to reduce the opening width of the fixture and cut the shading angle to 30 degrees. It is an object of the present invention to provide a lighting fixture that has appropriate light distribution and further suppresses a decrease in efficiency when both lights are turned on.

[Means for Solving the Problems] In order to achieve the above object, the lighting equipment according to the present invention has the following features:
It is a lighting equipment with two lamps installed above and below, and the above 2
The focal point K of the parabolic reflector that reflects the luminous flux emitted from the lamp of the lamp is the line segment H, 1 {, above, which connects the center H1 of the upper lamp and the center H2 of the lower lamp,
It is characterized by being located approximately between the point that internally divides the line segment H, I{2 into H1 K:H2 K-1:3 and the point H2.

[Function] According to the above configuration, the reflected light can be cut to a shielding angle of 30 degrees or less and concentrated in the range of 40 to 60 degrees. Furthermore, the opening width of the instrument can be narrowed. Furthermore, the shape of light distribution can be optimized.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a lighting fixture according to an embodiment of the present invention, and FIG. 2 is a plan view and a side view of this lighting fixture. Second
FIG. 2(a) is a plan view, which is the view seen when installed on the ceiling, and FIGS. 2(b) and 2(c) are side views. Dotted lines represent elements viewed through.

FIG. 1 is an enlarged cross-section viewed from the same direction as FIG. 2(c).

In these figures, 1 is the external body of the lighting fixture, 2 is the ceiling mounting part (near the position indicated by 2 is the ceiling surface), 3 is the upper lamp, 4 is the socket of the upper lamp,
5 is a lower lamp, 6 is a socket for the lower lamp, 7 is an aluminum reflector which is a feature of this embodiment, and 8 is a reflector 7.
9 is an upper reflecting plate, 10 is an attachment for the upper reflecting plate 9, and 11 is a louver.

In the lighting fixture of this embodiment, the focal point K of the reflectors 7 and 8 is located at the center position H of the upper lamp 3. and the center of the lower ramp 5 @
It was set exactly at the midpoint between I{2. In addition, the reflectors 7 and 8
The axes of their parabolic shapes are rotated 43 degrees from the vertical.

FIG. 3 and FIG. 4 are cross-sectional views showing the state of emission of the luminous flux in the lighting fixture of this embodiment. FIG. 3 shows the case where only the lower lamp is lit, and FIG. 4 shows the case where only the upper lamp is lit. These figures show that when the lower lamp is on, both reflected light and direct light with a shading angle of 30 degrees or less are cut off, and when the upper lamp is on, both reflected light and direct light with a shading angle of 50 degrees or less are cut off. I know that there is.

Next, the shape of the light distribution of the lighting fixture of the present invention will be described with reference to FIGS. 5 to 11.

FIG. 5 shows the focal point K of the reflectors 7 and 8 in FIG.
The light distribution when set to the position shown below is shown. The figure (a) shows the case where one lower lamp is turned on, and the figure (b) shows the case where one upper lamp is turned on. It can be seen that even when one lower lamp is turned on, the light flux with a shading angle of 30 degrees or less is cut off. Also, the lower one light is lit at 30
It can be seen that it is a wide illumination type that can concentrate light in a range of about 45 degrees, and that it is a narrow illumination type with high illuminance directly below when one light is lit on the upper side. Figure (c) shows the case where two lights, upper and lower, are lit.

FIG. 6 is a comparative example, and shows the light distribution when the focal point K of the reflectors 7 and 8 is set at the position of point B in FIG. The figure (a) shows the case where one lower lamp is turned on, and the figure (b) shows the case where one upper lamp is turned on. When only one light is lit on the lower side, the light distribution condition is very poor.

FIG. 7 shows the focal point K of the reflectors 7 and 8 in FIG.
The light distribution when set to the position shown below is shown. Similarly, in FIG. 8, the focal point K is at the position of the point D, in FIG. 9, the focal point K is at the position of the point E, in FIG. 10, the focal point K is at the position of the point F, and in FIG.
The light distribution when each is set at the position of point G is shown.

In both figures, (a) shows one light on the lower side, and (b) shows one light on the upper side.
This is the case when a light is turned on. In either case, it can be seen that the lighting of the lower one lamp is of the wide illumination type, and the lighting of the upper one lamp is of the narrow illumination type.

[Effects of the Invention] As explained above, according to the present invention, since the focal point of the reflector of the lighting fixture is kept within a predetermined range, the shading angle can be cut at 30 degrees while narrowing the aperture width of the lighting fixture. It is possible to provide appropriate light distribution both when the top lamp is lit and when the bottom lamp is lit, and furthermore, it is possible to suppress a decrease in efficiency when both lamps are lit. Also, since there is an appropriate reflector whether the lamp is installed on the top or the bottom, (1) When the lamp is installed on the top, ■Reflected light,
Direct light can be suppressed with a shading angle of 30 degrees.

■Since the light can be focused at 30 to 45 degrees, it is possible to increase the distance between fixtures.

■Can be used as a wide illumination type lighting fixture.

■By concentrating the light at 30-45 degrees, the efficiency of the fixture can be greatly improved.

(2) When the lamp is installed on the bottom side, ■Reflected light,
Both direct light can be suppressed with a shading angle of 50 degrees.

■Can be used as a narrow type lighting fixture with high direct illuminance.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a lighting fixture according to an embodiment of the present invention, FIG. 2 is a plan view and a side view of a lighting fixture of this embodiment, and FIGS. 3 and 4 are a sectional view of a lighting fixture of this embodiment. The cross-sectional views of FIGS. 5 to 11 showing the emission status of the luminous flux in the lighting equipment show the respective light distributions when the focal points K of the reflectors 7 and 8 are set at the positions of points A-G in FIG. 1. FIG. 1: External body of lighting equipment, 2: Ceiling mounting part, 3:
Upper lamp, 4: Upper lamp socket, 5: Lower lamp, 6: Lower lamp socket, 7.8: Aluminum reflector, 9: Upper reflector, 10: Mounting tool for upper reflector 9,
11: Louver, K: focal point, Hl, H2: center of lamp, R1 to R3, R5 to R7: reflected light, R4, R8:
Direct light.

Claims (1)

[Claims] (1) A lighting fixture with two straight tube lamps installed above and below, where the focal point K of the parabolic-shaped reflector plate provided on both sides of the two lamps to reflect the light emitted from each lamp is , approximately above the line segment H_1H_2 that connects the center H_1 of the upper lamp in the tube axis direction and the center H_2 of the lower lamp in the tube axis direction, and the line segment H_1H_2 is H_1K:H_2K-1.
A lighting fixture characterized by being located approximately between a point that is internally divided into :3 and a point H_2.