Variable color-output strobe

• US 4,978,892 A
• Filed: 12/27/1988
• Issued: 12/18/1990
• Est. Priority Date: 12/27/1988
• Status: Expired due to Term

• Current Assignee: Senshin Capital LLC (Intellectual Ventures LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Petrakos, Stephanie, Gaewsky, John P.
• Primary Examiner(s): LaRoche, Eugene R.
• Assistant Examiner(s): Yoo, Do Hyun
• Application Number:
  US07/289,693
• Time in Patent Office: 721 Days
• Field of Search: 315/358, 313/637, 313/643
• US Class Current: 315/358
• CPC Class Codes: H01J 61/95 Lamps with control electrode for varying intensity or wavelength of the light, e.g. for producing modulated light
• CPC Class Codes: H05B 41/325 by measuring the incident light

Abstract

A single flash discharge tube system is provided that is capable of emitting artificial light of a controlled and variable spectral output to compensate for photographic film color variations and/or extremes in scene color temperature. The flash tube contains a mixture of two or more gasses with each gas in the tube having a different ionization potential. When ionized, each has or combination thereof produces light having a different spectral output. The ionization of each gas is controlled by a trigger voltage applied to the flash tube in accordance with a code on a film container indicative of the color balance of film contained therein and/or sensing apparatus that determines scene color temperature.

Claims

1. A flash discharge apparatus, comprising:

an airtight housing through which light may be transmitted, for enclosing a mixture of gases;

a mixture of gases contained within said housing, with at least two of the gases forming said mixture having different ionization potentials;

means for generating at least two electrical potentials with each such electrical potential having a different period magnitude; and

means for coupling one of said electrical potentials to said gas mixture for the ionization of one of the gases forming said gas mixture without ionizing another, for the generation of a source of light having a particular spectral content and for the transmission of said light outwardly of said airtight housing.

2. The flash discharge apparatus of claim 1 wherein said gas mixture comprises neon gas having an ionization potential of approximately 21.47 electronvolts and argon gas having an ionization potential of approximatley 15.69 electronvolts.

3. The flash discharge apparatus of claim 2 wherein said gas mixture further comprises xenon gas having an ionization potential of approximately 12.08 electronvolts.

4. The flash discharge apparatus of claim 3 wherein said gas mixture further comprises krypton gas having an ionization potential of approximately 13.94 electronvolts.

5. The flash discharge apparatus of claim 1 wherein said airtight housing is a glass tube.

6. The flash discharge apparatus of claim 5 wherein said means for coupling said electrical ionization potentials to the enclosed gas mixture includes a single gas-ionizing electrode adjacent said glass tube for coupling a number of different ionization potentials to the gas mixture contained therein equal to the number of gases forming said gas mixture.

7. The flash discharge apparatus of claim 1, further comprising means for coupling one or more of said potentials to said gas mixture for the ionization of at least two of said gases.

8. A flash discharge lamp comprising:

an airtight glass tube through which light may be transmitted, for enclosing a mixture of gases;

a mixture of gases contained within said glass tube, with at least two of the gases forming said mixture having different ionization potentials; and

means for coupling an electrical potential to said gas mixture for the ionization of one or more gases forming said gaseous mixture that includes a number of different gas ionizing electrodes adjacent said glass tube equal to the number of gases forming said gas mixture with each electrode coupling a single ionization potential thereto, for the generation of a source of light having a particular spectral content and for the transmission of said light outwardly of said airtight glass tube.