Auxiliary illuminating device having an adjustable color temperature by controlling the amount of light passing through color filters

• US 6,755,555 B2
• Filed: 01/31/2002
• Issued: 06/29/2004
• Est. Priority Date: 01/31/2002
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Sobol, Robert E., Bianchi, Mark J, Bloom, Daniel M
• Primary Examiner(s): Husar, Stephen
• Assistant Examiner(s): Payne, Sharon
• Application Number:
  US10/061,466
• Publication Number:
  US 20030142496A1
• Time in Patent Office: 880 Days
• Field of Search: 362/3, 362/5, 362/260, 362/319, 362/293, 362/321, 362/280, 362/281, 362/282, 362/283
• US Class Current: 362/293
• CPC Class Codes: G02B 5/22 Absorbing filters G02B5/201 - G02B5/208 take precedence

Abstract

An auxiliary illuminating device that has an adjustable color temperature. The color temperature is adjusted by varying the light throughput of independently adjustable color filters.

Claims

1. A light source with an adjustable color temperature, comprising:

a broadband light source;

at least one color filter having a first color;

at least one color filter having a second color;

the at least one color filter having the first color and the at least one color filter having the second color configured to allow light from the broad band light source to pass through the filters;

at least one variable shutter configured to variably block the light passing through the at least one color filter having the first color;

at least one variable shutter configured to variably block the light passing through the at least one color filter having the second color;

a control system, the control system able to adjust the ratio of light passing through the color filter having the first color with respect to the color filter having the second color.

2. The light source of claim 1 where there is at least one area that allows the light from the broadband light source to pass through unfiltered.

3. The light source of claim 2 where there is at least one variable shutter configured to variably block the light passing through the unfiltered area.

4. The light source of claim 1 where the light source is configured to mount on a camera.

5. A light source with an adjustable color temperature, comprising:

a broad band light source;

at least one first color filter having a first color, the first color filter configured to allow light from the broad band light source to pass through the first color filter;

at least one second color filter having a second color, the second color filter configured to allow light from the broad band light source to pass through the second color filter;

at least one third color filter having a third color, the third color filter configured to allow light from the broad band light source to pass through the third color filter;

at least one first variable shutter configured to variably block the light passing through the at least one first color filter having the first color;

at least one second variable shutter configured to variably block the light passing through the at least one second color filter having the second color;

at least one third variable shutter configured to variably block the light passing through the at least one third color filter having the third color;

a control system, the control system able to adjust the ratio of light passing through the three color filters.

6. The light source of claim 5 where there is at least one area that allows the light from the broadband light source to pass through unfiltered.

7. The light source of claim 6 where there is at least one fourth variable shutter configured to variably block the light passing through the unfiltered area.

8. The light source of claim 5 further comprising:

a fourth color filter, the fourth color filter transmitting light over a fourth wavelength band.

9. A light source with an adjustable color temperature, comprising:

a broad band light source;

a plurality of first color filters having a first color, the first color filters configured to allow light from the broad band light source to pass through the first color filters;

a plurality of second color filters having a second color, the second color filters configured to allow light from the broad band light source to pass through the second color filters;

a plurality of first shutters configured to block the light passing through the plurality of first color filters having the first color;

a plurality of second shutters configured to block the light passing through the plurality of second color filters having the second color;

a control system, the control system able to adjust the ratio of light passing through the first color filters having the first color with respect to the second color filters having the second color, by changing the number of color filters blocked by the shutters.

10. The light source of claim 9 where there is at least one area that allows the light from the broadband light source to pass through unfiltered.

11. The light source of claim 10 where there is at least one shutter configured to block the light passing through the unfiltered area.

12. A light source with an adjustable color temperature, comprising:

a broad band light source;

at least one first color filter having a first color, the first color filter configured to allow light from the broad band light source to pass through the first color filter;

at least one second color filter having a second color, the second color filter configured to allow light from the broad band light source to pass through the second color filter;

means for variably blocking the light passing through the at least one first color filter having the first color;

means for variably blocking the light passing through the at least one second color filter having the second color;

a control system, the control system able to adjust the ratio of light passing through the first color filter having the first color with respect to the second color filter having the second color.