Electro-optical system and method of displaying images

• US 5,537,258 A
• Filed: 11/20/1992
• Issued: 07/16/1996
• Est. Priority Date: 11/20/1991
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Takemura, Yasuhiko, Yamazaki, Shunpei
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): Robbins, Thomas
• Application Number:
  US07/979,780
• Time in Patent Office: 1,334 Days
• Field of Search: 359/629, 359/634, 358/60, 358/53, 348/742, 348/759, 348/760, 348/761
• US Class Current: 359/634
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

An electro-optical system such as an image display system and a method of displaying images are described. Laser beams of three primary colors are emitted from three lasers in a time sharing mode. These laser beams are directed onto the same optical path and then separately given optical information from the same optical modulating device in accordance with images of the respective primary colors. By this structure, displacement of constituent color images can be effectively avoided.

Claims

1. An electro-optical system comprising a plurality of dye lasers, each of said dye lasers emitting a beam having a wavelength different for each of said plurality of dye lasers, optical aligning means for aligning laser beams as emitted from said lasers with a same axis, optical expanding means for expanding the laser beams aligned with said axis by said optical aligning means, and a light bulb arranged on an extension of said axis accompanied with a display means for separately directing optical images of a plurality of colors to a first surface of said light bulb in synchronism with the operation of said plurality of dye lasers.

2. The electro-optical system as claimed in claim 1 wherein the laser beams as emitted from the said lasers are polarized in one plane and said two-dimensional optical switch is a matrix device consisting of a liquid crystal panel.

3. The electro-optical system as claimed in claim 1 further comprising an image projection screen.

4. The electro-optical system as claimed in claim 3 wherein said screen is arranged on the extension of said axis.

5. The electro-optical system as claimed in claim 3 further comprising projecting means for projecting the laser beams reflected by said optical switch onto said screen.

6. The electro-optical system as claimed in claim 5 further comprising polarizing means for polarizing the laser beams, as emitted from said lasers, in one plane and wherein said two-dimensional optical switch is a matrix device consisting of a liquid crystal panel.

7. The system of claim 1 wherein each of said plurality of dye lasers is activated by a laser beam emitted from a common laser device.

8. An electro-optical system comprising:

means comprising a plurality of dye lasers, each of said dye lasers emitting a beam having a wavelength different for each of said plurality of dye lasers, for separately generating light beams of a plurality of colors propagating on a same optical path in turns;

an optical device for expanding the light beams propagating on the same optical path;

means for modulating the expanded light beams of the plurality of colors propagating on the same optical path in accordance with optical images of the plurality of colors to be displayed; and

means for projecting the modulated light beams onto a screen in turns displaying a color image corresponding to the optical images of the plurality of colors;

wherein said modulating means is a light bulb accompanied with a display means for separately directing optical images of the plurality of colors to a first surface of said light bulb in synchronism with the operation of said light beams generating means.

9. The system as claimed in claim 8 wherein said light beam generating means comprises a combination of three lasers capable of emitting laser beams of three primary colors and an optical system for directing the laser beams onto the same optical path.

10. The system as claimed in claim 8 wherein said modulating means is a liquid crystal panel.

11. The system as claimed in claim 8 wherein said light bulb is composed of a liquid crystal panel comprising a pair of transparent substrates having opposed inside surfaces coated with transparent conductive films and a plurality of reflective metallic pads which are formed on one of the transparent conductive films, isolated from each other and individually connected with one of said transparent conductive films through photoconductive elements.

12. The system as claimed in claim 8 further comprising another optical device for expanding the modulated light beams in advance of the projection thereof.

13. The system of claim 8 wherein each of said plurality of dye lasers is activated by a laser beam emitted from a common laser device.

14. A method of forming a color image comprising:

emitting light pulses of a plurality of colors in turns;

passing the light pulses through a light modulating device;

controlling said light modulating device in synchronism with the transmission of the light pulses of the plurality of colors to modulate each light pulse in accordance with a component image of a full color image to be displayed; and

projecting the modulated light pulses onto a screen,

wherein said light pulses are directed to transmit through a common optical path before passing said light modulating device and wherein said light modulating device comprises a light bulb accompanied with a display means for separately directing optical images of a plurality of colors to a first surface of said light bulb in synchronism with said light pulses.

15. An electro-optical system comprising:

means for separately generating light beams of a plurality of colors propagating on a same optical path in turns;

an optical device for expanding the light beams propagating on the same optical path;

means for modulating the expanded light beams of the plurality of colors propagating on the same optical path in accordance with optical images of the plurality of colors to be displayed; and

means for projecting the modulated light beams onto a screen in turns displaying a color image corresponding to the optical images of the plurality of colors,

wherein said modulating means comprises a light bulb accompanied with a display means for separately directing optical images of the plurality of colors to a first surface of said light bulb in synchronism with the operation of said light beams generating means.

16. The system recited in claim 15, wherein said light bulb is composed of a liquid crystal panel comprising a pair of transparent substrates having opposed inside surfaces coated with transparent conductive films and a plurality of reflective metallic pads which are formed on one of the transparent conductive films, isolated from each other and individually connected with one of said transparent conductive films through photoconductive elements.