Light source apparatus for separating white light into light components of a plurality of colors

• US 5,096,280 A
• Filed: 06/25/1990
• Issued: 03/17/1992
• Est. Priority Date: 06/27/1989
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Hamada, Hiroshi
• Primary Examiner(s): Ben, Loha
• Application Number:
  US07/542,926
• Time in Patent Office: 631 Days
• Field of Search: 350/317, 350/311, 350/312, 350/237, 350/169, 350/170, 350/339 F, 350/340, 350/402, 350/403, 350/408, 350/416, 350/438, 350/332, 350/354, 350/445, 350/446, 358/302, 346/107 R, 354/482, 354/483, 362/166, 362/169, 362/347
• US Class Current: 359/634
• CPC Class Codes: G02B 27/1046 for use with transmissive spatial light modulators
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10

Abstract

A light source apparatus for separating a white light into light components of a plurality of colors, includes a white light source and at least two dichroic mirrors. Each mirror selects a light with a particular wavelength band from a visible light so as to transmit the light with the selected wavelength band therethrough. The mirrors reflect light with a wavelength band other than the selected wavelength band so that the transmitted wavelength bands of the mirrors are different from each other. The mirrors are arranged opposite to each other with respect to the white light source. The apparatus also includes condenser lenses which are combined with each of the dichroic mirrors. The light reflected by each of the dichroic mirrors is returned to the white light source.

Claims

1. A light source apparatus for separating a white light into light components of a plurality of colors, comprising:

a white light source for producing visible light;

at least two dichroic mirrors, each dichroic mirror selecting light having a particular wavelength band from said visible light so as to transmit said light having said particular wavelength band therethrough, each dichroic mirror reflecting light components having particular wavelength bands that are different from said particular wavelength band transmitted therethrough so that each dichroic mirror transmits light having a different wavelength band therethrough, said dichroic mirrors being arranged opposite to each other with respect to said white light source; and

condenser lenses, each condenser lens being combined with a dichroic mirror;

said dichroic mirrors reflecting light components not transmitted therethrough towards said white light source.

2. The light source apparatus as claimed in claim 1, wherein said dichroic mirrors are spherically formed;

said condenser lenses being arranged so that a distance between each of said condenser lenses and said white light source is longer than a distance between a corresponding dichroic mirror and said white light source.

3. The light source apparatus as claimed in claim 1, wherein a surface of each of said condenser lenses is spherical on a side corresponding to said white light source and each of said dichroic mirrors being formed on the spherical surface of each of said condenser lenses.

4. The light source apparatus as claimed in claim 1, wherein each of said dichroic mirrors is arranged so that a distance between each of said dichroic mirrors and said white light source is longer than a distance between a corresponding condenser lens and said white light source, each of said dichroic mirrors being flatly formed and having a plane surface perpendicular to an optical axis of each of said condenser lenses.