JPH0311761Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a floodlight using a metal halide lamp.

[Prior Art] When the metal halide lamp 1 is lit horizontally (including a lit state diagonally other than vertically),
As shown in FIGS. 5a and 5b, the supersaturated additive adheres to the wall of the lower half of the arc tube 2, forming a yellow-brown adhesive film 3 on the lower half. Therefore, the light emitted upward is the discharge light of a metal halide lamp, and is a bluish-white light.

On the other hand, the light emitted downward becomes yellow light because this discharge light passes through the yellow-brown adhesive film 3.

When the light emitted upward and the light emitted downward are irradiated in different directions by a reflector, color unevenness of blue and yellow occurs on the irradiated surface.

[Problem to be solved by the invention] By the way, in the case of a projector having a reflecting mirror 4 which is a parabolic mirror vertically symmetrical with respect to the lamp axis as shown in Fig. 6, as shown in Fig. 7 a and b, blue reflected light
There was a problem in that the yellow reflected light X ₁ and the yellow reflected light X ₂ did not overlap on the irradiation surface, causing color unevenness due to the yellow portion Y and the blue portion B.

FIG. 8 shows a reflector with asymmetric light distribution. In this reflector with asymmetric light distribution, one light distribution is emitted from the entire reflector, so the light distribution by the upper half of the reflector 4 is different from that of the reflector. The light distribution in the lower half is different, and therefore, in this light distribution, the irradiation direction of the reflected light X ₁ of the upper half of the reflecting plate 4 and the reflected light X ₂ of the lower half are different, as shown in the figure, and the above-mentioned color unevenness occurs.

9a to 9c show examples of reflectors with asymmetric light distribution as described above, in which figure a shows the blue light distribution by the upper half of the reflector 4, and figure b shows the light distribution by the lower half of the reflector 4. The light distribution of yellow light is shown, and each light distribution is completely different, and the light distribution of the entire reflecting plate 4 obtained by combining is shown in figure c. Therefore, this device causes uneven coloring.

The present invention has been developed in view of the above-mentioned problems, and its purpose is to provide a floodlight that does not cause color unevenness even when the metal halide lamp is arranged horizontally other than vertically and turned on. be.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a floodlight that distributes asymmetric light using a cylindrical reflector that surrounds a metal halide lamp mounted horizontally. The reflector is divided into upper and lower halves with the center of the direction as the boundary, and is divided into an upper reflector and a lower reflector, so that the light distribution of the upper reflector and the light distribution of the lower reflector are similar to each other and overlap each other. The reflective surfaces of the upper and lower reflectors are formed like this.

[Function] According to the present invention, the reflector is divided into upper and lower halves with the axial center of the metal halide lamp as the border, and the light distribution of the upper reflector and the lower reflector are divided into upper and lower halves. The reflective surfaces of the upper and lower reflectors are formed so that the light distributions of the reflectors are similar to each other and overlap, so the blue light reflected by the upper reflector and the yellow light reflected by the lower reflector. Since they are similar in shape and overlap, color unevenness will not occur on the irradiated surface. Figure 1 is an explanatory diagram of reflection by a symmetrical reflector 4. In the upper reflector 4a, part of the blue light is reflected downward at the reflective surface a as shown in Figure 2 b, and the rest is reflected upward at the reflective surface b. In the lower reflector 4b, a part of the yellow light is reflected upward at the reflective surface d as shown in FIG. 2a, and the rest is reflected downward at the reflective surface c.
The lights reflected in the same direction have similar shapes and overlap on the irradiation surface, so that color unevenness does not occur. In FIG. 1, BY indicates an overlapping region [Example] The present invention will be explained below with reference to an example.

FIG. 3 shows an embodiment of the present invention, in which the reflector plate 4
The lamp has a cylindrical shape with a bottom that is widened in the front, and a socket 5 is provided at the rear end, and the metal halide lamp 1 is installed in the socket 5 in a horizontal state.

The reflector 4 is divided into upper and lower halves with the axial center of the metal halide lamp 1 as the boundary, and the light distribution of each of the reflection surfaces of the upper reflector 4a and the lower reflector 4b is similar to the light distribution of the entire fixture. The light distribution pattern is as shown in FIGS. 4a and 4b.

When the metal halide lamp 1 is lit horizontally, the light distribution of the blue light reflected by the upper reflector 4a and the light distribution of the yellow light reflected by the lower reflector 4a overlap, resulting in the overall light distribution being as follows. The light distribution becomes as shown in Figure 4c, and color unevenness due to blue light and yellow light does not occur. In the above embodiment, the lamps are arranged horizontally, but it is of course possible to arrange the lamps in a horizontal direction, including an oblique direction other than the vertical direction.

[Effects of the invention] The present invention provides a floodlight that distributes asymmetric light using a cylindrical reflector that surrounds a metal halide lamp that is mounted in a horizontal position. The lower half is divided into an upper reflector and a lower reflector, and the reflective surfaces of the upper and lower reflectors are adjusted so that the light distribution of the upper reflector and the light distribution of the lower reflector are similar to each other and overlap. This prevents color unevenness even if there is a difference in the color of the emitted light at the top and bottom of the lamp due to the adhered film that occurs when the metal halide lamp is placed horizontally other than vertically and lit. This has the advantage of being able to distribute light without causing light generation.

[Brief explanation of the drawing]

Figure 1 is a diagram explaining the principle of the present invention, Figures 2a and b are diagrams explaining the light distribution of the same as above, Figure 3 is a schematic configuration diagram of an embodiment of the present invention, and Figures 4 a to c are the operation of the same as above. Explanatory diagram,
Figures 5a and b are longitudinal and cross-sectional views of the arc tube of a metal halide lamp, Figure 6 is an explanatory diagram of an example using a conventional symmetrical reflector, and Figures 7a and b are the same arrangement as above. Optical explanatory drawing, FIG. 8 is a schematic configuration diagram of a conventional example,
9a to 9c are explanatory diagrams of the same operation as above, in which 1 is a metal halide lamp, 4 is a reflector, and 4a and 4b are upper and lower reflectors.

Claims (1)

[Scope of utility model registration request] In a floodlight that distributes asymmetric light using a cylindrical reflector that surrounds a metal halide lamp that is mounted horizontally, the reflector is divided into upper and lower halves with the axial center of the metal halide lamp as the border, and upper reflection is achieved. It is divided into a plate and a lower reflector, and the light distribution of the upper reflector,
A projector characterized in that the reflective surfaces of the upper and lower reflectors are respectively formed so that the light distribution of the lower reflector is similar to and overlaps with the light distribution of the lower reflector.