Liquid crystal projector

• US 5,313,234 A
• Filed: 01/19/1993
• Issued: 05/17/1994
• Est. Priority Date: 07/26/1991
• Status: Expired due to Fees

• Current Assignee: Sayett Group, Inc. (SpatiaLight, Inc.)
• Original Assignee: Sayett Group, Inc. (SpatiaLight, Inc.)
• Inventors: Edmonson, Orvan, Mathewson, Christopher
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Dowling, William C.
• Application Number:
  US08/006,144
• Time in Patent Office: 483 Days
• Field of Search: 353/52, 353/54, 353/55-56, 353/60-61, 353/119-122, 353/DIG. 3, 359/66, 359/79
• US Class Current: 353/61
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• CPC Class Codes: H04N 9/3141 Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14

Abstract

A liquid crystal display panel projector including a housing having a thermally isolated hot compartment which has an illumination source and a cold compartment which retains liquid crystal display panel. The housing includes individual cooling fluid paths for the hot and cold compartments. The display panel is disposed in the cold compartment where it is isolated from the thermal energy of the illumination source to provide a substantially stable thermal environment.

Claims

1. A liquid crystal display projector comprising:

(a) a housing having a hot compartment including a fluid inlet and a fluid outlet spaced apart from the fluid inlet and a cold compartment including a fluid inlet and a fluid outlet wherein the cold compartment is at least partially thermally isolated from the hot compartment, and the fluid outlet of the cold compartment is in communication with the fluid inlet of the hot compartment;

(b) an illumination source within the hot compartment between the fluid inlet and the fluid outlet so that fluid flow through the hot compartment from the fluid inlet to the fluid outlet cools the illumination source, the source producing an illumination beam, and means in the illumination beam for removing heat from the beam before it passes from the hot compartment to the cold compartment;

(c) a fluid flow path extending from the inlet in the cold compartment through the cold compartment then through the inlet in the hot compartment past the illumination source to the outlet in the hot compartment;

(d) a liquid crystal display panel in the cold compartment the display panel having a first and a second side, at least one of the sides in the thermal contact with the flow path;

(e) means for conducting a cooling fluid through the flow path from the inlet in the cold compartment to the outlet in the hot compartment; and

(f) means for directing the illumination beam from the illumination source to the display panel to produce an image beam.

2. The liquid crystal display projector of claim 1, further comprising focusing means for focusing the image beam upon a screen.

3. A projector for a display panel, comprising:

(a) a housing having thermally isolated first and second compartments;

(b) cooling means for causing a cooling fluid to flow along a flow path sequentially from an inlet, through the second compartment, into the first compartment through the first compartment and exhausting the fluid from an outlet in the first compartment;

(c) an illumination source in the first compartment in the fluid flow path for producing an illumination beam and thermal energy and transferring the thermal energy to the cooling fluid;

(d) heat retention means in a thermally conductive path between the first and second compartments for retaining a portion of the thermal energy produced by the illumination source within the first compartment;

(e) a display panel in the second compartment; and

(f) reflection means for passing the illumination beam from the illumination source through the display panel.

4. A projector for projecting an image on a liquid crystal display panel onto a screen, comprising:

(a) a housing having substantially thermally isolated first and second compartments wherein a light path extends from the first compartment through the second compartment;

(b) a cooling passageway in the second compartment;

(c) a light source in the first compartment for projecting visible light along the light path;

(d) an infrared reflector condenser lens in the first compartment disposed in the light path for reflecting a portion of the radiation produced by the light source while permitting the passage of visible light;

(e) a first surface mirror in the second compartment for directing visible light in the light path towards the passageway;

(f) a fresnel lens disposed in the light path for focusing the illumination beam;

(g) a liquid crystal display panel in the second compartment disposed in the light path such that a first surface of the display panel thermally contacts a portion of the cooling passageway and a portion of the illumination beam passes through the liquid crystal display to form an image beam;

(h) a second first surface mirror in the second compartment for reflecting the image beam; and

(i) focusing means in the second compartment for focusing the image beam upon an imaging surface.

5. The projector of claim 4, further comprising means for removing heat from the first compartment.

6. A projector for projecting an image from a display panel onto a screen, comprising:

(a) a housing including a cold compartment having a fluid inlet and a hot compartment having a fluid outlet, wherein the hot compartment is at least partially thermally isolated from the cold compartment;

(b) a display panel substantially within the cold compartment, the display panel having a first side and a second side;

(c) illumination means in the hot compartment for producing an illumination beam;

(d) optics means for directing the illumination beam from the illumination means through the display panel to form an image beam;

(e) focusing mean for projecting the image beam upon the screen; and

(f) a fluid communication pathway extending between the inlet and the outlet for providing continuous fluid flow from the inlet into the cold compartment in direct thermal contact with at least one of the first and the second sides of the display panel then passing through the hot compartment in thermal contact with the illumination means and then exiting the housing through the fluid outlet.

7. A method for projecting an image beam from a liquid crystal display panel upon a screen, comprising:

(a) producing an illumination beam in a first compartment of a housing the first compartment having a cooling fluid outlet;

(b) single passing the illumination beam through a liquid crystal display panel in a second compartment to form the image beam the second compartment having a cooling fluid inlet;

(c) thermally isolating the first compartment from the second compartment; and

(d) removing heat from the illumination beam as it passes from the first compartment to the second compartment;

(e) passing a flow of cooling air sequentially from the inlet in the second compartment, by the liquid crystal display panel, then into the first compartment and then through the first compartment to an outlet in the first compartment; and

(f) focusing the image beam upon the screen.