Method of mixed illumination

• US 4,120,026 A
• Filed: 08/19/1976
• Issued: 10/10/1978
• Est. Priority Date: 08/21/1975
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Saito, Masato, Myodo, Osamu, Tsuchihashi, Michihiro, Yamanoshita, Makoto, Katsura, Hidetoshi, Maeyama, Koichiro, Uchida, Yasushi
• Primary Examiner(s): Moses, Richard L.
• Application Number:
  US05/715,653
• Time in Patent Office: 782 Days
• Field of Search: 240/1 R, 240/1.3, 240/2 C, 240/41 R, 240/41.1, 240/51.11 R, 240/20, 240/3.1
• US Class Current: 362/231
• CPC Class Codes: F21V 9/40 with provision for controlling spectral properties, e.g. colour, or intensity
• CPC Class Codes: F21W 2131/406 for theatres, stages or film studios

Abstract

Beautifully and balanced colored shadows can be cast of an object by using a lamp for emitting colored light in the range yellow to red, a lamp for emitting green colored light and a lamp for emitting colored light in the range violet to blue to give intensity ratios of illumination in the ranges of

0.05 ≦ I.sub.R /(I.sub.R + I.sub.G + I.sub.B) ≦ 0.85;

0.05 ≦ i.sub.g /(i.sub.r + i.sub.g + i.sub.b) ≦ 0.8; and

0.02 ≦ I.sub.B /(I.sub.R + I.sub.G + I.sub.B) ≦ 0.8

wherein I_R designates an intensity of illumination caused by irradiating with only the lamp in the R group the shadow of an object cast by both of the lights of the lamps in the G group and the B group; I_G designates an intensity of illumination caused by irradiating with only the lamp in the G group the shadow of the object cast by both of the lights of the lamps in the R group and the B group and I_B designates an intensity of illumination caused by irradiating with only the lamp in the B group the combination of the shadow of the object cast by the light of the lamp in the R group and the shadow of another object cast by the light of the lamp in the G group.

Claims

1. A method of mixing illumination from a plurality of sources for use in casting beautiful and balanced colored shadows of opaque objects which comprises the steps of:

arranging a plurality of color lamps in three groups including an R group of at least one lamp for emitting colored light in the range yellow to red, a G group of at least one lamp for emitting green light, and a B group of at least one lamp for emitting colored light in the range violet to blue; and

irradiating a pair of opaque objects with colored light emitted by the color lamps in the three groups to cause colored shadows of the objects characterized by intensity ratios of illumination in the ranges of

space="preserve" listing-type="equation">0.05 ≦

I.sub.R /(I.sub.R + I.sub.G + I.sub.B) ≦

0.85;

space="preserve" listing-type="equation">0.05 ≦

i.sub.g /(i.sub.r + i.sub.g + i.sub.b) ≦

0.8; and

space="preserve" listing-type="equation">0.02 ≦

I.sub.B /(I.sub.R + I.sub.G + I.sub.B) ≦

0.8

wherein I_R designates an intensity of illumination caused by irradiating with only the lamp in the R group the shadow of one of the opaque objects cast by both of the lights of the lamps in the G group and the B group, I_G designates an intensity of illumination caused by irradiating with only the lamp in the G group the shadow of the one of the opaque objects cast by both of the lights of the lamps in the R group and the B group, and I_B designates an intensity of illumination caused by irradiating with only the lamp in the B group the combination of the shadow of the one of the opaque objects cast by the light of the lamp in the R group and the shadow of the other of the opaque objects cast by the light of the lamp in the G group.

2. A method of mixing illumination according to claim 1 wherein the intensity ratios of illumination lie in the range surrounded by the full line connecting the points a, b, c, d, e and f in the triangular coordinate diagram of FIG. 2 with each of the intensity ratios I_R /(I_R + I_G + I_B), I_G /(I_R + I_G + I_B) and I_B /(I_R + I_G + I_B) being designated by i_R, i_G and i_B respectively.

3. A method of mixing illumination according to claim 1 wherein the intensity ratios of illumination lie in the range surrounded by the full line connecting the points H, J, K, L, M and N in the triangular coordinate diagram of FIG. 2 with each of the intensity ratios I_R /(I_R + I_G + I_B), I_G /(I_R + I_G + I_B) and I_B /(I_R + I_G + I_B) being designated by i_R, i_G and i_B respectively.

4. A method of mixing illumination according to claim 1 wherein the arranging step comprises arranging color lamps in three groups including an R group consisting of a high pressure sodium lamp, a G group consisting of a green metal halide lamp and a B group consisting of a blue metal halide lamp.

5. A method of mixing illumination according to claim 1 including the step of moving the positions of the three groups of color lamps.

6. A method of mixing illumination according to claim 1 wherein the arranging step comprises arranging color lamps in three groups including an R group having a yellow color lamp, an orange color lamp, a red color lamp, a high pressure sodium lamp, an orange metal halide lamp and a red metal halide lamp, a G group having a green color lamp and a green metal halide lamp, and a B group having a violet color lamp, a blue color lamp, a violet metal halide lamp and a blue metal halide lamp.