JPS5911364Y2 - ceiling light fixtures - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a ceiling-embedded lighting fixture, and its purpose is to illuminate a wide area of the floor with uniform illuminance.

1 to 4 show a conventional example, in which a main body 1 is approximately cylindrical and embedded in a ceiling 2, and a socket 1 is attached to the bottom 3 of the main body 1 to hold a lamp 5. A reflecting plate 6 is provided.

This reflecting plate 6 is approximately bowl-shaped, and the side peripheral surface 7 is a parabola in cross section, and the axis of the parabola is inclined at an angle θ with respect to the axis of the entire reflecting plate 6.
Lamp 5 is located at the focus of the parabola.

The light distribution curve of this lamp 5 is as shown in FIG.
The incident light is reflected in the axial direction of the paraboloid, that is, in a direction tilted by θ with respect to the axial direction of the lamp, and the light distribution curve of this device is directly below the lamp and tilted by θ with it, as shown in Figure 3. There are parts with high luminous intensity in the direction, and the illuminance of the floor surface is maximum directly below as shown in FIG. 4, and the effective illuminance range is not sufficient, which is uneconomical and at the same time causes uneven brightness.

The present invention has been made in view of the above points, and will be explained below based on the drawings.

5 to 8 show an embodiment of the present invention, and the external appearance is the fifth embodiment.
As shown in the figure, the main body 10 is a cylindrical body with a bottom and is embedded in the ceiling 12 with the bottom 11 facing upward.A lamp 13 is attached to the bottom 11 of the ceiling 12 and held in a socket 14. 15 are provided.

The side peripheral surface 14 of the reflector 15 has a parabolic cross-sectional shape, and the axis of the parabola is inclined at an angle θ with respect to the axis of the entire reflector 15, and the angle at which the end of the reflector 15 is viewed from the lamp 13 is larger than θ by β. The lamp 13 is located at the focal point of the paraboloid, and the angle (view angle) seen from the focal point of the paraboloid, that is, the lamp 13 is α.

As shown in Fig. 6, the light distribution curve of the lamp has its maximum luminous intensity in the direction perpendicular to the optical axis of the lamp 13, and the effective luminous intensity range having a luminous intensity of 80% or more of the maximum luminous intensity is centered on the direction of the maximum luminous intensity and extends at an angle α. It is a range.

The light in this effective luminous intensity range enters the paraboloid of the reflector 15 and is reflected in the direction of its axis, that is, in a direction inclined by 'θ from the vertical axis passing through the lamp, and the light distribution curve of the fixture is as shown in FIG. The maximum luminous intensity is in the direction tilted by 'θ from the vertical line, and if this inclination θ is set to, for example, 45 degrees to 60 degrees depending on the height of the floor from the ceiling, the horizontal illuminance curve of the floor will be 8th.
As shown in the figure, it becomes almost uniform.

As described above, according to the present invention, the floor surface level is constant, the brightness is uniform, the effective illumination range is wide, and it is economical.

[Brief explanation of the drawing]

Figures 1 to 4 show conventional examples, where Figure 1 is a cross-sectional front view, Figure 2 is the light distribution curve of the lamp, Figure 3 is the light distribution curve of the fixture, and Figure 4 is the horizontal illuminance of the floor. It is a curve. 5 to 8 show embodiments of the present invention, FIG. 5 is a cross-sectional front view of the device, FIG. 6 is the light distribution curve of the lamp, FIG. 7 is the light distribution curve of the device, and FIG. 8 is the light distribution curve of the device. This is a horizontal illuminance curve on the floor surface.

Claims (1)

[Scope of utility model registration request] In a ceiling lighting fixture that has a reflector surrounding the lamp and is open at the bottom and is attached to the ceiling to illuminate the floor, the lamp must emit a luminous intensity of 80% or more of its maximum luminous intensity within an angle α centered on the horizontal direction. The reflector has a paraboloid of revolution centered on the lamp, and the paraboloid of revolution has the lamp as its focal point and its axis is tilted approximately 45 degrees to 60 degrees with respect to the vertical line, and the angle of view from the lamp is approximately 45 to 60 degrees. A ceiling lighting fixture characterized in that the angle α coincides with the angle α.