Reflective lamp

• US 4,315,186 A
• Filed: 06/26/1979
• Issued: 02/09/1982
• Est. Priority Date: 07/03/1978
• Status: Expired due to Term

• Current Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
• Original Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
• Inventors: Shinada, Hidehiro, Sawada, Michiyuki, Hirano, Tomiyoshi
• Primary Examiner(s): Demeo, Palmer C.
• Assistant Examiner(s): Hostetter, Darwin R.
• Application Number:
  US06/052,211
• Time in Patent Office: 959 Days
• Field of Search: 313/112, 313/113, 313/114, 313/110, 313/111
• US Class Current: 313/111
• CPC Class Codes: H01K 1/28 Envelopes; Vessels
• CPC Class Codes: H01K 1/32 provided with coatings on the walls; Vessels or coatings thereon characterised by the material thereof

Abstract

Provided is a reflective lamp comprising a bulb including a front lens section and a reflective mirror section fused thereto, said front lens section consisting of glass material containing neodymium and coated on its inner surface with a first thin film reflecting infrared rays and permitting visible lights to be transmitted therethrough, said reflective mirror section consisting of glass material containing no neodymium and coated on its inner surface with a second thin film reflecting visible lights. The lamp is capable of preventing the rise in the temperature of the bulb and yet providing a sufficiently high color rendering. Further, the lamp can offer the advantage of reducing its manufacturing cost.

Claims

1. A reflective lamp comprising a bulb and a filament contained therein, said bulb including a front lens section and a reflective mirror section fused thereto, said front lens section consisting of glass material containing neodymium in the range of 0.5 to 5.0% by weight as calculated in terms of Nd₂ O₃ based upon the total weight of glass material and coated on its inner surface with a first thin film reflecting infrared rays and permitting visible light to be transmitted therethrough, said reflective mirror section consisting of neodymium-free glass material and coated on its inner surface with a second thin film reflecting visible light but transmitting infra-red rays therethrough.

2. The reflective lamp according to claim 1 wherein said first thin film is an electric conductive film and said second thin film is a cold mirror film.

3. The reflective lamp according to claim 2 wherein said electric conductive film is a film formed of a halide chosen from the group consisting of a halide of Sn and a halide of In, and of a minute amount of a material chosen from the group consisting of Sb and Sn;

and said cold mirror film is a multi-layer interference film which consists of MgF₂ -Ge-MgF₂ -TiO₂.

4. The reflective lamp according to claim 1 wherein said first thin film is an electric conductive film;

and said second thin film is a deposited film of Al.

5. The reflective lamp according to claim 4 wherein said electric conductive film is a film which consists of a halide chosen from the group consisting of Sn and In, which halide contains a minute amount of one metal chosen from the group consisting of Sn and Sb.

6. The reflective lamp according to claim 1 wherein the amount of neodymium in said front lens section is in the range of 1.0 to 2.5% by weight as calculated in terms of Nd₂ O₃, based upon the total weight of said glass material.

7. The reflective lamp according to claim 3 or 5 wherein a large number of projections for diffusion of light are provided on the inner surface of said front lens section.