Method and apparatus for selectively viewing captioning

• US 7,119,762 B2
• Filed: 08/19/2002
• Issued: 10/10/2006
• Est. Priority Date: 08/19/2002
• Status: Expired due to Fees

• Current Assignee: David P. Shelton, Jeremy C. Price
• Original Assignee: David P. Shelton, Jeremy C. Price
• Inventors: Shelton, David P., Price, Jeremy C.
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): DHARIA, PRABODH M
• Application Number:
  US10/223,003
• Publication Number:
  US 20040032379A1
• Time in Patent Office: 1,513 Days
• Field of Search: 345 7- 9, 345/156, 345/158, 345/87, 345/419, 348/742, 348/750, 348/743, 348/758, 359/309, 359/23, 359/277, 359/26, 359/1, 359/15, 359/19, 359/630, 349/78, 349/5, 364/525, 438/166, 438/479
• US Class Current: 345/7
• CPC Class Codes: G09B 21/009 Teaching or communicating with deaf persons G09B21/04 takes precedence; deaf and dumb persons G09B21/00

Abstract

Alphanumeric images are displayed in common view in one color on a background of a different color using a liquid crystal projection device. The two colors are sufficiently similar so they are not distinguished by the unaided eye of the viewer. A color selective material in the form of glasses is provided to a subclass of the viewers in the audience to enable these viewers to distinguish the alphanumeric subtitles from the background. This material extinguishes either the alphanumeric images or the background, thereby either providing darkened letters on a light background or light letters on a darkened background. The projection and viewing apparatus can be utilized as a motion picture closed captioning system for a mixed audience of hearing impaired and non hearing impaired individuals to permit the hearing impaired to view the subtitles while those individuals not wearing such wavelength selective glasses would not see the subtitles.

Claims

1. An apparatus for projecting onto a screen means viewable by a plurality of persons a display including alphanumeric images which can be viewed only by selected persons, the apparatus comprising:

first laser means emitting a first polarized beam at a first visible wavelength,

second laser means emitting a second polarized beam at a second visible wavelength,

one of said first and second polarized beam forming alphanumeric images, and said first and second visible wavelengths being sufficiently close that a color difference therebetween cannot be distinguished by the unaided eye,

polarizing beam splitting means for combining said first and second beams, the combined beams being emitted in the same direction with orthogonal polarization orientation,

liquid crystal display means for displaying a selected alphanumeric image having a first surface for receiving said combined beams and a second surface provided with a polarizing means for outputting only vertically polarized light, and

lens means for projecting said light passed through said second surface onto the screen means,

wherein the alphanumeric images can be seen only by selected persons wearing a wavelength selective filter adjacent the eyes.

2. The apparatus as set forth in claim 1, wherein the polarization of the beam emitted from said first laser means is vertical.

3. The apparatus as set forth in claim 2, wherein the polarization of the beam emitted from said second laser means is horizontal.

4. The apparatus set forth in claim 1, wherein said first and second laser means produce wavelengths in a yellow-green part of the visible spectrum.

5. The apparatus set forth in claim 1, further including third laser means emitting a vertically polarized beam at a third visible wavelengths, with the second visible wavelength being about halfway between said first and third visible wavelength, and dichroic beam splitting means for combining the first and third visible beams which are then combined with the beam from said second laser means by said polarizing beam splitting means,

whereby the alphanumeric image is projected by the beams from said first and third laser means and a background is projected by the beam from said second laser means and the viewing means transmits only the beams projecting said image.

6. The apparatus set forth in claim 3, further including third laser means emitting a vertically polarized beam with a third visible wavelength, with the second wavelength being about halfway between said first and third wavelengths, and dichroic beam splitting means for combining the first and third beams, which are then combined with the beam from said second laser means,

whereby the alphanumeric image is projected by the beams from said first and third laser means and a background is projected by the beam from said second laser means and the viewing means transmits only the beams projecting said image.

7. In combination, the apparatus as set forth in claim 1, and a wavelength selective filter constructed and arranged for mounting adjacent the eyes of a viewer.

8. The combination set forth in claim 7, wherein said wavelength selective filter is a holographic notch filter.

9. The apparatus set forth in claim 7, wherein said wavelength selective filter is mounted in an eyeglass type frame.

10. A method of projecting alphanumeric displays onto a screen viewable by a plurality of persons, where the displays are viewable only by selected persons, comprising the steps of:

providing a first polarized laser beam at a first visible wavelength;

providing a second polarized laser beam at a second visible wavelength,

wherein one of the first polarized beams forms alphanumeric images and the first and second wavelengths are sufficiently close that a color difference therebetween cannot be distinguished by the unaided eye,

passing said first and second beams through a polarizing beam splitter to combine said first and second beams;

passing said combined beams through a liquid crystal display with input and output sides having the selected alphanumeric image inputted thereto, with polarizing means at the output side thereof,

passing the beam from the liquid crystal display through a lens means for projecting a resulting image onto the screen viewable by a plurality of persons, and

providing viewing means comprising a wavelength selective filter to selected persons for viewing the one of said first and second wavelengths containing image.

11. The method as set forth in claim 10, wherein the polarization of said beam emitted from said first laser means is vertical.

12. The method as set forth in claim 11, wherein the polarization of said beam emitted from said second laser means is horizontal.

13. The method set forth in claim 10, wherein said laser means produce wavelengths in the yellow-green part of the visible spectrum.

14. The method set forth in claim 10, wherein said wavelength selective filter is a holographic notch filter.

15. The method set forth in claim 10, wherein said viewing means include an eyeglass type frame.

16. The method set forth in claim 10, further including a third laser means emitting a polarized beam at third wavelength with the second wavelength being about halfway between said first and third wavelengths, and combining the third beam with the first beam by dichroic beam splitting means, and then combining the combined first and third beams with the beam from said second laser producing means by said polarizing beam splitting means, whereby the alphanumeric image is projected by the beams from said first and third laser producing means and a background is projected by the beam from said second laser producing means,

said viewing means only transmitting those beams projecting said image.

17. The method set forth in claim 12, further including a third laser means emitting a polarized beam at third wavelength with the second wavelength being about halfway between said first and third wavelengths, and combining the third beam with the first beam by dichroic beam splitting means, and then combining the combined first and third beams with the beam from said second laser producing means by said polarizing beam splitting means, whereby the alphanumeric image is projected by the beams from said first and third laser producing means and a background is projected by the beam from said second laser producing means.

18. The method set forth in claim 10, wherein said viewing means transmits said first and third wavelengths.