Lighting equipment

• US 4,961,028 A
• Filed: 11/10/1988
• Issued: 10/02/1990
• Est. Priority Date: 12/07/1987
• Status: Expired due to Term

• Current Assignee: Hayashi Tokei Kogyo Kabushiki Kaisha
• Original Assignee: Hayashi Tokei Kogyo Kabushiki Kaisha
• Inventors: Tanaka, Hiroaki
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): Powell, Mark R.
• Application Number:
  US07/269,493
• Time in Patent Office: 691 Days
• Field of Search: 315/65, 315/88, 315/90, 315/91, 315/93, 315/76
• US Class Current: 315/91
• CPC Class Codes: H05B 47/29 Circuits providing for substitution of the light source in case of its failure

Abstract

Equipment for lighting a work area has a plurality of light sources, at least one of which is usually lighted; the others are spare light sources and are usually turned off. The equipment has means such as an optical fiber to conduct light from the light source to the work area. Converting means is provided with the equipment to distribute electric power selectively to the light sources. Detecting means is also installed in the equipment to detect cutting off of the light source which is in the lighted condition. The converting means changes the distribution of the output from the power supply to a light source other than the light source which was cut off.

Claims

1. A lighting equipment having automatic lamp substitution comprising;

a plurality of light sources,

means for leading the light from the plurality of light sources to an appropriate portion,

switching means for selectively distributing power to at least one of the plurality of light sources in order to activate it, means for adjusting the volume of said power,

detecting and comparing means for distinguishing between failure of the activated light source and the minimum volume of the power to the activated light source so as to detect only failure of the activated light source; and

said switching means changes the power supply from the failed light source to at least another one of the plurality of light sources responding to a signal from said detecting means.

2. The lighting equipment of claim 1 wherein;

p1 said detecting and comparing means detects the failure of the light source by detecting current flow to the light source.

3. The lighting equipment having automatic lamp substitution of claim 1 wherein;

said detecting and comparing means detects the failure of the light source by detecting current flow of the circuit of said power at least at two positions in the circuit of said power.

4. The lighting equipment having automatic lamp substitution of claim 1 further including means for turning on any one of the plurality of light sources for predetermined period to check if the light source is operable.

5. The lighting equipment of claim 1 including means for warning of the failure of the light source.