Laser-based display with position sensitive detector

• US 20060132716A1
• Filed: 12/17/2004
• Published: 06/22/2006
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Johnson, Noble M., Peeters, Eric, Bringans, Ross D.
• Granted Patent: US 7,232,229 B2
• Time in Patent Office: Days
• US Class Current: 353/29
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: G03B 21/60 characterised by the nature of the surface
• 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

A display apparatus includes a luminescent screen having pixels formed from blue, green and red luminescent material that are selectively activated by a laser beam to generate a full color image. The display utilizes a closed loop laser scanning/modulating arrangement in which a Position Sensitive Device (PSD) located next to the screen is used to determine the location of the impinging beam, and to transmit timing/location data to the laser addressing system. The laser addressing system uses the timing/location data to adjust and/or modulate the laser beam, thereby generating high-energy beam pulses that activate the selected pixels. The PSD includes vertical strips located along the side edges of the screen, or a sheet that is located behind the screen and accessed, for example, by way of slits or apertures formed in the screen material. The PSD sheet is coupled to an optional power source to form a photon-multiplication device.

Claims

1. A display apparatus comprising:

a luminescent screen including a plurality of pixels, each pixel including a luminescent region comprising a luminescent material;

a position sensitive detector including a sensor mounted adjacent to the luminescent screen, and a detector circuit connected to the sensor; and

a laser system for directing a laser beam onto the luminescent screen and the sensor, and for controlling the laser beam in response to data received from the detector circuit such that the laser beam activates selected pixels of the plurality of pixels to produce a desired image, wherein the data is generated in response to a detected position of the laser beam on the sensor.

2. The display apparatus according to claim 1, wherein the laser system includes means for scanning the laser beam in a predetermined pattern across a surface of the luminescent screen, and for controlling the laser beam to transmit a relatively high energy pulse to each of the selected pixels.

3. The display apparatus according to claim 1,

wherein the luminescent screen includes first pixels having red luminescent regions, second pixels having green luminescent regions, and blue pixels having blue luminescent regions, and

wherein the laser system includes a first laser for addressing the first, second and third pixels.

4. The display apparatus according to claim 3, wherein the laser beam generated by the first laser has a predetermined wavelength in one of the visible light spectrum, the near-ultraviolet spectrum, and the ultraviolet spectrum.

5. The display apparatus according to claim 3, further comprising a second laser for addressing the first, second and third pixels, wherein the first and second lasers generate laser beams having a single predetermined wavelength.

6. The display apparatus according to claim 1, wherein each luminescent region comprises at least one of fluorescing nano-particles and phosphorus.

7. The display apparatus according to claim 1, wherein the laser system includes:

means for scanning the laser beam along parallel scan paths,

means for comparing the data received from the detector circuit with image source data including a pixel location of a selected pixel, and

means for modulating the laser beam from a relatively low power to a relatively high power when the timing/location data indicates that the laser beam is at the pixel location of the selected pixel, thereby causing the selected pixel to emit visible light.

8. The display apparatus according to claim 1, wherein the sensor comprises one or more elongated strips extending parallel to one or more edges of the luminescent screen.

9. The display apparatus according to claim 8, wherein the one or more sensor strips comprises a first sensor strip extending along a first side edge of the luminescent screen, and a second sensor strip extending along a second side edge of the luminescent screen.

10. The display apparatus according to claim 8, wherein the sensor comprises a sensor sheet mounted such that the luminescent screen is between the laser system and the sensor sheet.

11. The display apparatus according to claim 10, further comprising a plurality of electrodes connected between edges of the sensor sheet and the detector circuit.

12. The display apparatus according to claim 10,

wherein the luminescent screen includes non-luminescent border regions located between the luminescent regions of each adjacent pair of pixels, and

wherein the non-luminescent border regions define slits for passing said laser beam to the sensor sheet.

13. The display apparatus according to claim 10, wherein the luminescent regions of each pixel defines a central aperture for passing said laser beam to the sensor sheet.

14. The display apparatus according to claim 10, wherein the luminescent screen further comprises:

a photocathode plate including a photocathode material layer formed on the sensor sheet; and

a photoanode plate including said luminescent regions of said plurality of pixels,

wherein the photocathode plate is separated from the photoanode plate by a vacuum region; and

wherein the luminescent screen includes means for generating an electric field in the vacuum region such that electrons freed from the photocathode material layer by the laser beam are accelerated into the luminescent regions of selected pixels.

15. The display apparatus according to claim 1, wherein the laser system is mounted onto a portable electronic device.

16. The display apparatus according to claim 1, wherein the luminescent screen is mounted onto a first cover of a foldable structure, and the laser system is mounted onto a second cover of the foldable structure.

17. A display apparatus comprising:

a luminescent screen including a plurality of pixels, each pixel including a luminescent region comprising a luminescent material;

laser means for directing a laser beam onto the luminescent screen; and

means for detecting a location on the luminescent screen impinged by the laser beam, and for transmitting to the laser means data indicating the detected location.

18. The display apparatus according to claim 17, wherein the laser means further comprises means for controlling the laser beam in response to data received from the detector circuit such that the laser beam activates selected pixels of the plurality of pixels to produce a desired image.