Additive tri-color lamphouse for a photographic printer

• US 4,188,111 A
• Filed: 09/15/1978
• Issued: 02/12/1980
• Est. Priority Date: 09/15/1978
• Status: Expired due to Term

• Current Assignee: Kreonite, Inc. (Dunning Photo Equipment, Inc.)
• Original Assignee: Kreonite, Inc. (Dunning Photo Equipment, Inc.)
• Inventors: Marvin, Roger L.
• Primary Examiner(s): Wintercorn, Richard A.
• Application Number:
  US05/942,878
• Time in Patent Office: 515 Days
• Field of Search: 355/1, 355/32, 355/35, 355/37
• US Class Current: 355/37
• CPC Class Codes: G03B 27/54 Lamp housings; Illuminating means
• CPC Class Codes: G03B 27/73 Controlling exposure by variation of spectral composition, e.g. multicolor printers

Abstract

An additive tri-color lamp house having three lamps for conveying filtered light into a mixing chamber and illuminating a photographic image contained on a photographic film. The illuminated image is then projected onto a photosensitive paper for the purpose of making photographic prints and copies. The lamp house is characterized by having a combination of additive primary color filters and subtractive primary color filters positioned in front of the lamps and the amount of each additive primary color (i.e. red, green and blue) conveyed through the filters is controlled. By the proper positioning of the color filters in front of the lamps, the time required for proper exposure of the three separate emulsion layers on conventional color print paper is approximately equal.

Claims

1. An additive tri-color lamp house for a photograph printer, the lamp house comprising:

a lamp house housing;

a first lamp, a second lamp, and a third lamp, said lamps mounted in said housing for passing light therethrough;

a fixed filter holder mounted in said housing, said holder disposed in front of said lamps, said holder including a first yellow filter positioned in front of said first lamp, a red filter positioned in front of said second lamp, and a first magenta filter positioned in front of said third lamp;

light guide means mounted in said housing and disposed in front of said yellow, red and magenta filters for receiving the filtered light therefrom; and

a mixing chamber disposed in said housing and communicating with said light guide means for receiving the filtered light therefrom and mixing the filtered light therein.

2. The lamp house as described in claim 1 further including a first moveable filter holder pivotally mounted in said housing and disposed between said light guide means and said fixed filter holder, said first moveable filter holder including a green filter, a shutter, and a blue filter, when said first moveable filter holder is pivoted said green filter is indexed in front of said yellow filter, said shutter is indexed in front of said red filter, and said blue filter is indexed in front of said first magenta filter.

3. The lamp house as described in claim 1 further including a second moveable filter holder pivotally mounted in said housing and disposed between said light guide means and said fixed filter holder, said second moveable filter holder including a second magenta filter, when said second moveable filter holder is pivoted, said second magenta filter is indexed in front of said first yellow filter.

4. The lamp house as described in claim 1 further including a third moveable filter holder pivotally mounted in said housing and disposed between said light guide means and said fixed filter holder, said third moveable filter holder including a second yellow filter, when said third moveable filter holder is pivoted said second yellow filter is indexed in front of said first magenta filter.

5. The lamp house as described in claim 1 wherein said light guide means is a first light transfer rod, a second light transfer rod, and a third light transfer rod, one end of said first rod is positioned in front of said first yellow filter, one end of said second rod is positioned in front of said red filter, one end of said third rod is positioned in front of said first magenta filter, the opposite ends of said rods received in said mixing chamber for transmitting the filtered light received through said filters into said mixing chamber.

6. The additive tri-color lamp house for a photographic printer, the lamp house comprising:

a lamp house housing;

a first lamp, a second lamp, and a third lamp, said lamps mounted in said housing for passing light therethrough;

a fixed filter holder mounted in said housing, said holder disposed in front of said lamps, said holder including a first yellow filter positioned in front of said first lamp, a red filter positioned in front of said second lamp, and a first magenta filter positioned in front of said third lamp;

light guide means mounted in said housing and disposed in front of said yellow, red and magenta filters for receiving the filtered light therefrom;

a mixing chamber disposed in said housing and communicating with said light guide means for receiving the filtered light therefrom and mixing the filtered light therein;

a first moveable filter holder pivotally mounted in said housing and disposed between said light guide means and said fixed filter holder, said first moveable filter holder including a green filter, a shutter, and a blue filter, when said first moveable filter holder is pivoted said green filter is indexed in front of said first yellow filter, said shutter is indexed in front of said red filter, and said blue filter is indexed in front of said first magenta filter;

a second moveable filter holder pivotally mounted in said housing and disposed between said light guide means and said fixed filter holder, said second moveable filter holder including a second magenta filter, when said second moveable filter holder is pivoted, said second magenta filter is indexed in front of said first yellow filter; and

a third moveable filter holder pivotally mounted in said housing and disposed between said light guide means and said fixed filter holder, said third moveable filter holder including a second yellow filter, when said third moveable filter holder is pivoted said second yellow filter is indexed in front of said first magenta filter.