Filter, illumination device and illumination method

• US 6,554,454 B1
• Filed: 06/27/2000
• Issued: 04/29/2003
• Est. Priority Date: 06/28/1999
• Status: Expired due to Fees

• Current Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Original Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Inventors: Kitano, Hirohisa
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Zeade, Bertrand
• Application Number:
  US09/603,949
• Time in Patent Office: 1,036 Days
• Field of Search: 362/293, 362/583, 362/280, 362/282, 362/284, 362/322, 362/323, 362/324, 362/317, 362/311, 359/889, 359/885, 359/890, 359/891, 359/892, 355/35
• US Class Current: 362/293
• CPC Class Codes: H04N 1/504 Reproducing the colour component signals line-sequentially

Abstract

It is an object to provide an improved filter or illumination device. In order to achieve the above object, an illumination device is provided having multiple optical color filters wherein a first time period, required for at least one of the multiple optical color filters to pass across a light path, is different from a second time period, required for each of the other optical color filters to pass across the light path. According to another aspect of this invention, an illumination device has multiple optical color filters and an optical member wherein a boundary, which extends in a direction, is provided between one of the multiple optical color filters and another one of the multiple optical color filters, and the optical member includes an inlet for receiving light from the optical color filters, wherein the inlet extends in a first direction corresponding to the direction of the boundary when the boundary crosses the light path, for a greater distance than the inlet extends in a second direction.

Claims

1. An illumination device comprising:

a light source for emitting light;

an optical member for receiving the light emitted from the light source;

a rotatable wheel having multiple optical color filters which are arranged between said light source and said optical member, the rotatable wheel having at least two filters evenly positioned about the the center of the rotatable wheel for each color of filter on the rotatable wheel, and

a drive mechanism for driving said rotatable wheel such that the multiple optical color filters sequentially pass across a light path from said light source to said optical member;

wherein each respective one of the optical color filters affects the light emitted by said light source while the respective one optical color filter passes across the light path, and

a first time period, required for at least one of the multiple optical color filters to pass across the light path, is different from a second time period, required for each respective one of the other optical color filters to pass across the light path.

2. An illumination device as claimed in claim 1, wherein

said multiple optical color filters respectively allow blue(B), green(G) and red(R) light to pass through or be reflected.

3. An illumination device as claimed in claim 1, wherein

an area of said at least one of the multiple optical color filters is different from an area of each respective one of the other optical color filters.

4. An illumination device as claimed in claim 1, wherein

said drive mechanism drives said wheel to rotate.

5. An illumination device as claimed in claim 1, wherein

said multiple optical color filters are sequentially arranged on said wheel in a rotational direction of the wheel, and each of said multiple optical color filters has a fan configuration.

6. An illumination device as claimed in claim 5, wherein

at least one of the multiple optical color filters has a central angle extending in the rotational direction that is different from that of each respective one of the other optical color filters having a color different than the color of the at least one of the multiple optical color filters.

7. An illumination device as claimed in claim 1, wherein

a boundary is provided between one of said multiple optical color filters and another one of said multiple optical color filters, said boundary extending in a direction, and said optical member includes an inlet for receiving light from said optical color filters, wherein said inlet extends in a first direction, corresponding to the direction of said boundary when the boundary crosses the light path, for a greater distance than said inlet extends in a second direction, corresponding to a direction of movement of said multiple optical color filters across the light path.

8. An illumination device comprising:

a light source for emitting light;

an optical member for receiving the light emitted from the light source;

a rotatable wheel having multiple optical color filters which are arranged between said light source and said optical member, the rotatable wheel having at least two filters evenly positioned about the the center of the rotatable wheel for each color of filter on the rotatable wheel, and

a drive mechanism for driving said rotatable wheel such that the multiple optical color filters sequentially pass across a light path from said light source to said optical member;

wherein each respective one of the optical color filters affects the light emitted by said light source while the respective one optical color filter passes across the light path, and

a boundary is provided between one of said multiple optical color filters and another one of said multiple optical color filters, said boundary extending in a direction, and said optical member includes an inlet for receiving light from said optical color filters,

wherein said inlet extends in a first direction, corresponding to the direction of said boundary when the boundary crosses the light path, for a greater distance than said inlet extends in a second direction.

9. An illumination device as claimed in claim 8, wherein

said multiple optical color filters respectively allow blue(B), green(G) and red(R) light to pass through or be reflected.

10. An illumination device as claimed in claim 8, wherein

said drive mechanism drives said wheel to rotate.

11. An illumination device as claimed in claim 8, wherein

said multiple optical color filters are sequentially arranged on said wheel in a rotational direction of the wheel, and each respective one of said multiple optical color filters has a fan configuration.

12. An illumination device as claimed in claim 11, wherein

said boundary extends in a direction of a radius of rotation of said color wheel.

13. An illumination device as claimed in claim 11, wherein

said second direction is in the rotational direction of the wheel.