Portable microdisplay system

• US 6,909,419 B2
• Filed: 09/15/1998
• Issued: 06/21/2005
• Est. Priority Date: 10/31/1997
• Status: Expired due to Fees

• Current Assignee: Kopin Corporation
• Original Assignee: Kopin Corporation
• Inventors: LO, JASON, Zavracky, Matthew, Pombo, Stephen A., Jacobsen, Jeffrey, Bumgardner, Rodney, Herrmann, Frederick P., Chern, Wen-Foo, Ong, Hiap L., Fan, John C. C., Tsaur, Bor-Yeu, Richard, Alan, GALE, RON
• Primary Examiner(s): Tran, Henry N.
• Assistant Examiner(s): Lesperance, Jean
• Application Number:
  US09/153,744
• Publication Number:
  US 20020154082A1
• Time in Patent Office: 2,471 Days
• Field of Search: 345/88, 345/89, 345/90, 345/92, 345/104, 345/182, 345/183, 345/536, 348/207, 348/222, 34833301-33312, 348/335, 348/358, 348/370, 348/371
• US Class Current: 345/102
• CPC Class Codes: G06F 1/1616 with folding flat displays, e.g. laptop computers or notebooks having a clamshell configuration, with body parts pivoting to an open position around an axis parallel to the plane they define in closed position
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/163 Wearable computers, e.g. on a belt
• CPC Class Codes: G06F 1/1632 External expansion units, e.g. docking stations
• CPC Class Codes: G06F 1/1637 Details related to the display arrangement, including those related to the mounting of the display in the housing
• CPC Class Codes: G06F 1/1656 Details related to functional adaptations of the enclosure, e.g. to provide protection against EMI, shock, water, or to host detachable peripherals like a mouse or removable expansions units like PCMCIA cards, or to provide access to internal components for maintenance or to removable storage supports like CDs or DVDs, or to mechanically mount accessories mounting of accessories to a computer display G06F1/1607; display hoods G06F1/1603; cooling arrangements for portable computers G06F1/203
• CPC Class Codes: G06F 1/1662 Details related to the integrated keyboard
• CPC Class Codes: G06F 1/1686 the I/O peripheral being an integrated camera
• CPC Class Codes: G06F 1/1698 the I/O peripheral being a sending/receiving arrangement to establish a cordless communication link, e.g. radio or infrared link, integrated cellular phone details of antennas disposed inside a computer H01Q1/2266
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes
• CPC Class Codes: H04N 9/30 using solid-state colour display devices

Abstract

An active matrix color crystal display has an active matrix circuit, a counterelectrode panel and an interposed layer of liquid crystal. The active matrix display is located in a portable microdisplay system that has a display computer that generates images to be displayed on the liquid crystal display and connected to the active matrix liquid crystal display. A data link transmits data at a rate of speed of greater than 200 Mbytes per second in series for at least a portion between the display computer and the active matrix liquid crystal display. In a preferred embodiment, the display system has a randomizing device that alternates the amplifier through which an analog video signal passes.

Claims

1. A portable microdisplay system comprising:

an active matrix liquid crystal display including an array of at least 75,000 pixel electrodes, the active matrix liquid crystal having an active matrix circuit having an array of transistor circuits formed in a first plane, each transistor circuit being connected to a pixel electrode in an array of pixel electrodes having an area of 200 mm² or less, and a counter electrode panel extending in a second plane that is parallel to the first plane;

a light source positioned to illuminate the array of pixel electrodes;

a lens positioned to receive an image formed on the active matrix liquid crystal display and that magnifies the image by at least a factor of two;

a display circuit that generates images to be displayed on the liquid crystal display and connected to the active matrix liquid crystal display, the counterelectrode panel receiving an applied voltage such that the display circuit actuates the pixel electrodes to write an image, flashes the light source to illuminate the image, and switches the applied voltage to the counterelectrode to erase the image; and

a data link that transmits data at a rate of speed of greater than 100 Mbytes per second in series between the display circuit computer and the active matrix liquid crystal display.

2. A portable microdisplay system of claim 1 wherein the array of the pixel electrodes comprises an array of at least 640×

480.

3. A portable microdisplay system of claim 2 wherein the light source is a backlight of at least one light emitting diode device.

4. A portable microdisplay system of claim 2 wherein the light source is remote from the display and the light is transmitted by a fiber optics cable.

6. A portable microdisplay system of claim 2 wherein the display is a color sequential and further comprising at least three light emitting diode devices for illuminating the array of pixel electrodes.

7. A portable microdisplay system of claim 2 wherein the array of pixel electrodes comprises an array of at least 1280×

1024.

8. A portable microdisplay system of claim 7 where the data link has a transmission rate of speed greater than 200 Mbytes per second.

9. A portable microdisplay system of claim 7 where the data link has a transmission rate of speed greater than 300 Mbytes per second.

10. A portable microdisplay system of claim 7 wherein the microdisplay and lens are mounted on a helmet.

11. A portable microdisplay of claim 1 wherein the active matrix liquid display has a liquid crystal layer interposed in a cavity between the first and the second planes, the cavity having a depth of less than 3 microns.

12. A portable microdisplay of claim 11 further comprising an oxide layer over the pixel electrode arrays.

13. A portable microdisplay of claim 11 wherein the depth of the cavity is 2 μ

m or less.

14. A portable microdisplay system of claim 11 wherein the display circuit further times the initializing of the pixel electrodes to a selected state after switching the applied voltage to the counterelectrode and prior to the writing of a further image.

15. A portable microdisplay system of claim 14 wherein the selected state that the pixel electrodes are set to is such that the liquid crystal relaxes to a transmissive state.

16. A portable microdisplay system of claim 1 further comprising a randomizing device for alternating the amplifier through which an analog video signal passes.

17. A portable microdisplay system of claim 1 wherein the display circuit includes a switch that switches the setting of a common voltage that enters the display.

18. A portable microdisplay system of claim 17 wherein the display circuit includes a timing control circuit that controls the switch.

19. A portable microdisplay system of claim 17 wherein at one setting of the common voltage the image is presented on the display, and at a second setting the image is erased.

5. A portable microdisplay system of 2 wherein the light source varies intensity and has a light source for ambient daylight and a light source for night vision.

20. A digital camera comprising:

a housing;

an image sensor within the housing that senses an image;

a signal processor within the housing that processes signals from the image sensor;

an active matrix display positioned within the housing and having an active matrix circuit including an array of transistor circuits in a first plane, a counter electrode panel extending in a second plane that is parallel to the first plane, and a plurality of pixel electrodes that displays an image, the pixel electrodes being connected to the signal processor;

a light source within the housing positioned to illuminate the active matrix display;

a display control circuit within the housing that controls activation of the pixel electrodes, the display control circuit being connected to the active matrix display by a data link that transmits data at a rate of speed of greater than 100 Mbytes per second in series, the counter electrode panel of the active matrix display receiving an applied voltage such that the display circuit actuates the pixel electrodes to write an image, flashes the light source to illuminate the image, switches the applied voltage to the counter electrode to erase the image, and initializes the pixel electrodes to a selected specific state prior to the writing a further image; and

a lens optically coupled to the matrix display to magnify an image on the display.

21. A digital camera of claim 20 further comprising an alphanumeric display.

22. A digital camera of claim 21 wherein the active imaging area of less than 158 mm².

23. A digital camera of claim 21 wherein the matrix display having at least 640×

480 pixel electrodes.

24. A digital camera of claim 21 further comprising a mirror for projecting the image from the microdisplay.

25. A digital camera of claim 20 wherein the active matrix display is a color sequential display has at least 320×

240 pixel electrodes and an active imaging area of less than 200 mm² and is a color sequential display system with an LED backlight system.

26. A digital camera of claim 25 wherein the selected state that the pixel electrodes are set to is such that the liquid crystal relaxes to a transmissive state.

27. A digital camera of claim 20 further comprising a randomizing device alternates the amplifier through which an analog video signal passes.

28. A digital camera of claim 20 wherein the display control circuit includes a switch that sets the level of a common voltage that enters the display.

29. A digital camera of claim 28 wherein the display circuit includes a timing control circuit that controls the switch.

30. A digital camera of claim 28 wherein at one setting of the common voltage the image is presented on the display, and at a second setting the image is erased.

31. A portable microdisplay system comprising

an active matrix liquid crystal display including an array of at least 75,000 pixel electrodes, the active matrix liquid crystal display having an active matrix circuit having an array of transistor circuits formed in a first plane, each transistor circuit being connected to a pixel electrode in an array of pixel electrodes having an active area of less than 158 mm², and a counter electrode panel extending in a second plane that is parallel to the first plane;

a light source positioned to illuminate the active matrix display;

a display control circuit that controls activation of the pixel electrodes, the display control circuit being connected to the active matrix liquid crystal display by a data link that transmits data at a rate of speed of greater than 100 Mbytes per second in series, the counter electrode panel of the active matrix liquid crystal display receiving an applied voltage such that the display circuit actuates the pixel electrodes to write an image, flashes the light source to illuminate the image, switches the applied voltage to the counter electrode to erase the image, and initializes the pixel electrodes to a selected state prior to the writing of a further image; and

a lens positioned to receive an image formed on the active matrix liquid crystal display and magnify the image by at least a factor of two.

32. A portable communication system of claim 31 further comprising a delay locked-loop for eliminating clock skew including a voltage-controlled delay element located in a signal path, and a feedback path having a phase detector and integrator for controlling the voltage control delay.

33. A portable display system of claim 31 further comprising phase-locked loop including a voltage-controlled oscillator located in a signal path for generating an internal clock and a feedback path having a phase detector and integrator for controlling the voltage-controlled oscillator.

34. A portable display system of claim 31 wherein the selected state that the pixel electrodes are set to is such that the liquid crystal relaxes to a clear position.

35. A portable microdisplay system of claim 31 wherein the display control circuit includes a switch that sets the level of a common voltage that enters the display.

36. A portable microdisplay system of claim 35 wherein the display circuit includes a timing control circuit that controls the switch.

37. A portable microdisplay system of claim 35 wherein at one setting of the common voltage the image is presented on the display, and at a second setting the image is erased.

38. A portable microdisplay system comprising:

an active matrix liquid crystal display including an active matrix circuit having an array of transistor circuits formed in a first plane, each transistor circuit being connected to a pixel electrode in an array of pixel electrodes, and a counter electrode panel extending in a second plane that is parallel to the first plane;

a light source positioned to illuminate the array of pixel electrodes;

a lens positioned to receive an image formed on the active matrix liquid crystal display and that magnifies the image by at least a factor of two;

a display control circuit that generates images to be displayed on the liquid crystal display and connected to the active matrix liquid crystal display by a data link that transmits data at a rate of speed of greater than 100 Mbytes per second in series and to the light source, the display control circuit including a first switching circuit connected to the counterelectrode panel, the first switching circuit selecting a high or a low common voltage applied to the counterelectrode panel, a second switching circuit that selects a video or an inverted video signal to be transmitted to the display, and a timing control circuit that determines when the display control circuit actuates the pixel electrodes to write an image and flashes the light source to illuminate the image, when the second switching circuit selects the video or the inverted video signal, and when the first switching circuit selects the high or low common voltage applied to the counterelectrode to erase the image.