Color projection system

• US 6,450,649 B2
• Filed: 12/22/2000
• Issued: 09/17/2002
• Est. Priority Date: 12/24/1999
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: De Vaan, Adrianus Johannes Stephanes Maria
• Primary Examiner(s): Adams, Russell
• Assistant Examiner(s): SEVER, ANDREW T
• Application Number:
  US09/746,105
• Publication Number:
  US 20010055097A1
• Time in Patent Office: 634 Days
• Field of Search: 353/51, 353/20, 353/84, 353/31, 353/38, 359/9, 348/743, 348/742
• US Class Current: 353/84
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 5/09 Multifaceted or polygonal mirrors , e.g. polygonal scanning mirrors; Fresnel mirrors
• CPC Class Codes: H04N 9/3117 by using a sequential colour filter producing two or more colours simultaneously, e.g. by creating scrolling colour bands

Abstract

A color projection system includes a light source, a rotatable drum having a plurality of differently Colored bands, and a light modulation panel on which light beams reflected by the colored bands can be directed by way of scrolling. The apparatus directs the light beam from the light source onto a first group of juxtaposed bands. The light beam on each band is split and reflected into light beams having complementary colors and different directions of polarization. Light beams having a first direction of polarization are directed onto the light modulation panel, and light beams having a second direction of polarization are reflected onto a second rope of bands of the drum. The second group of bands is shifted by at least one band with respect to the first group of bands.

Claims

1. A color projection system comprising a light source, a rotatable drum having a plurality of differently colored bands, and a light modulation panel on which light beams reflected by the colored bands can be directed by way of scrolling, characterized in that the color projection system further comprises means for directing the light beam from the light source onto a first plurality of juxtaposed bands, means for splitting and reflecting the light beam on each band into light beams having complementary colors and different directions of polarization, means for directing light beams having a first direction of polarization onto the light modulation panel, and means for reflecting light beams having a second direction of polarization onto a second plurality of bands of the drum, which second plurality of bands is shifted by at least one band with respect to the first plurality of bands.

2. A color projection system as claimed in claim 1, characterized in that the first plurality of bands comprises at least one band more than the plurality of bands imaged on the light modulation panel.

3. The color projection system of claim 2, wherein the color projection system includes means for reflecting light beams having a second direction of polarization for a second time on a third plurality of bands of the drum, which third plurality of bands is shifted by at least two bands with respect to the first plurality of bands and by at least one band with respect to the second plurality of bands.

4. The color projection system of claim 3, wherein each band on the drum is provided with a dichroic layer, a subjacent ¼

λ

layer and a subjacent layer reflecting white light.

5. The color projection system of claim 2, wherein each band on the drum is provided with a dichroic layer, a subjacent ¼

λ

layer and a subjacent layer reflecting white light.

6. The color projection system of claim 2, wherein the bands consecutively reflect the colors red, green and blue towards the light modulation panel.

7. The color projection system of claim 2, wherein at least one white band is located between two colored bands.

8. The color projection system of claim 2, wherein an integrator plate is located between the light source and the drum, which integrator plate comprises a plurality of lenses and reflecting surfaces located next to the lenses and directed towards the drum, and a polarization conversion means is provided proximate to the light source.

9. A color projection system as claimed in claim 1, characterized in that the color projection system further comprises means for reflecting light beams having a second direction of polarization for a second time on a third plurality of bands of the drum, which third plurality of bands is shifted by at least two bands with respect to the first plurality of bands and by at least one band with respect to the second plurality of bands.

10. The color projection system of claim 9, wherein each band on the drum is provided with a dichroic layer, a subjacent ¼

layer and a subjacent layer reflecting white light.

11. The color projection system of claim 9, wherein the bands consecutively reflect the colors red, green and blue towards the light modulation panel.

12. The color projection system of claim 3, wherein at least one white band is located between two colored bands.

13. The color projection system of claim 9, wherein an integrator plate is located between the light source and the drum, which integrator plate comprises a plurality of lenses and reflecting surfaces located next to the lenses and directed towards the drum.

14. A color projection system as claimed in claim 1, characterized in that each band on the drum is provided with a dichroic layer, a subjacent ¼

λ

layer and a subjacent layer reflecting white light.

15. The color projection system of claim 14, wherein the bands consecutively reflect the colors red, green and blue towards the light modulation panel.

16. The color projection system of claim 14, wherein at least one white band is located between two colored bands.

17. The color projection system of claim 14, wherein an integrator plate is located between the light source and the drum, which integrator plate comprises a plurality of lenses and reflecting surfaces located next to the lenses and directed towards the drum, and a polarization conversion means is provided proximate to the light source.

18. A color projection system as claimed in claim 1, characterized in that the bands consecutively reflect the colors red, green and blue towards the light modulation panel.

19. A color projection system as claimed in claim 1, characterized in that at least one white band is located between two colored bands.

20. A color projection system as claimed in claim 1, characterized in that an integrator plate is located between the light source and the drum, which integrator plate comprises a plurality of lenses and reflecting surfaces located next to the lenses and directed towards the drum.

21. A color projection system as claimed in claim 1, characterized in that a polarization conversion means is provided proximate to the light source.