Portable projection display apparatus

• US 5,738,429 A
• Filed: 06/05/1995
• Issued: 04/14/1998
• Est. Priority Date: 06/28/1994
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Nohno, Hitoshi, Katagiri, Masayuki, Tagawa, Takao
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US08/462,882
• Time in Patent Office: 1,044 Days
• Field of Search: 353/122, 353/42, 353/101, 345/182, 345/183
• US Class Current: 353/122
• CPC Class Codes: G02F 1/133623 Inclined coloured light beams
• CPC Class Codes: G03B 21/132 Overhead projectors, i.e. capable of projecting hand-writing or drawing during action epidiascopic projectors G03B21/08
• CPC Class Codes: G06F 3/03542 Light pens for emitting or receiving light
• CPC Class Codes: G06F 3/0386 for light pen
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386

Abstract

The present projection display apparatus includes an illumination source, an LCD panel including a polarizing plate, a light projecting and receiving combinational lens, a screen, a light pen, a detection-use polarizing plate, a CCD, and a control circuit for controlling an operation of the LCD panel upon receiving a signal from the CCD. The combinational lens throws light of a display image from the LCD panel to project the light on the screen. Meanwhile, the lens receives light from the display image and luminescent spot light from the pen to focus them on the LCD panel and then reflect the same to make them incident on the CCD via the detection-use polarizing plate. The detection-use polarizing plate does not transmit the light of the display image.

Claims

1. A projection display apparatus comprising:

display image forming means for forming a display image to be projected on a projection screen;

luminescent spot image forming means, having an illumination source for signal input use, for forming a luminescent spot image by projecting light from the illumination source for input use on the projection screen;

image focusing means, provided between the display image forming means and the projection screen, for focusing a display image on the projection screen upon receiving light from the display image forming means, and receiving reflection light from the projection screen;

luminescent spot image extracting means for extracting light from the luminescent spot image out of a received incident light from the image focusing means;

luminescent spot image detecting means for detecting the luminescent spot image upon receiving the light from the luminescent spot image extracted by the luminescent spot image extracting means, a read frequency of the luminescent spot image detecting means being higher than a display frequency of the display image forming means; and

display control means, responsive to a detection signal representing the luminescent spot image detecting by the luminescent spot image detecting means, for controlling a display image forming operation of the display image forming means based on the detection signal.

2. A projection display apparatus comprising:

an illumination source for image display use;

display image forming means, including a liquid crystal display panel provided with a first polarizing plate and a second polarizing plate attached respectively to one and the other surfaces of a liquid crystal display cell, for forming a display image to be projected on a projection screen by transmitting light from the illumination source for image display use through the liquid crystal display panel, the first polarizing plate arranged opposite to the illumination source for image display use;

luminescent spot image forming means, having an illumination source for signal input use, for forming a luminescent spot image by projecting light from the illumination source for input use on the projection screen;

image focusing means, provided between the display image forming means and the projection screen, for focusing a display image on the projection screen upon receiving light from the display image forming means, and focusing reflection light received from the projection screen on the display image forming means;

a polarizing plate for detection use for transmitting light in a direction of polarization different from a direction of polarization of the second polarizing plate upon receiving light focused on the display image forming means by the image focusing means;

luminescent spot image detecting means for detecting the luminescent spot image upon receiving light transmitted through the polarizing plate for detection use;

display control means, responsive to a detection signal representing the luminescent spot image detected from the luminescent spot image detecting means, for controlling a display image forming operation of the liquid crystal display panel based on the detection signal; and

luminescent spot image focusing means, provided between the polarizing plate for detection use and the luminescent spot image detecting means, for focusing an image received from the polarizing plate for detection use through reduction on the luminescent spot image detecting means.

3. A projection display apparatus as claimed in claim 2, wherein the polarizing plate for detection use is arranged so that a direction of polarization in which the polarizing plate for detection use polarizes light is approximately perpendicular to a direction of polarization in which the second polarizing plate polarizes light.

17. A projection display apparatus as claimed in claim 2, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

18. A projection display apparatus as claimed in claim 3, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

4. A projection display apparatus comprising:

display image forming means for forming a display image to be projected on a projection screen;

luminescent spot image forming means, having an infra-red light emitting section for emitting an infra-red light, for forming an infra-red light luminescent spot image on the projection screen with the infra-red light from the infra-red light emitting section;

image focusing means, provided between the display image forming means and the projection screen, for focusing a display image on the projection screen upon receiving light from the display image forming means, and focusing reflection light received from the projection screen on the display image forming means;

an optical filter which operates to receive light emitted from the image focusing means to the display image forming means, transmit light components having wavelengths in a region outside an infra-red region out of the light, and scatter light having a wavelength in the infra-red region;

luminescent spot image detecting means for detecting the luminescent spot image upon receiving the light component having a wavelength in the infra-red region scattered by the optical filter;

display control means, responsive to a detection signal representing the luminescent spot image detected from the luminescent spot image detecting means, for controlling a display image forming operation of the display image forming means based on the detection signal;

the optical filter being attached close to the display image forming means; and

luminescent spot image focusing means, provided between the optical filter and the luminescent spot image detecting means, for focusing an image received from the optical filter through reduction on the luminescent spot image detecting means.

5. A projection display apparatus comprising:

display image forming means for forming a display image to be projected on a projection screen;

luminescent spot image forming means, having an illumination source for signal input use, for forming a luminescent spot image by projecting light from the illumination source for input use on the projection screen,

image focusing means, provided between the display image forming means and the projection screen, for focusing a display image on the projection screen upon receiving light from the display image forming means, and focusing reflection light received from the projection screen on the display image forming means;

a low-reflectance half mirror which is provided between the image focusing means and the display image forming means, and operates to receive light emitted from the image focusing means to the display image forming means, transmit a greater part of the received light, and reflect a smaller part of the received light;

image detecting means for detecting the luminescent spot image and the display image upon receiving light reflected on the half mirror; and

display control means, responsive to an image detection signal representing the luminescent spot image and the display image detected from the image detecting means, for deriving a differential image between the image detection signal and a display signal which has formed the display image on the display image forming means to extract a luminescent spot image signal representing only the luminescent spot image, and controlling a display image forming operation of the display image forming means based on the luminescent spot image signal.

6. A projection display apparatus as claimed in claim 5, further comprising:

image focusing means, provided between the half mirror and the image detecting means, for focusing a received image from the half mirror through reduction on the image detecting means.

7. A projection display apparatus as claimed in claim 5, further comprising:

light scattering means, provided between the half mirror and the image detecting means, for focusing the received image from the half mirror on the light scattering means itself.

8. A projection display apparatus as claimed in claim 5, further comprising:

a Fresnel lens provided between the half mirror and the image detecting means.

20. A projection display apparatus as claimed in claim 5, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

21. A projection display apparatus as claimed in claim 6, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

22. A projection display apparatus as claimed in claim 7, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

23. A projection display apparatus as claimed in claim 8, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

9. A projection display apparatus comprising:

an illumination source for image display use;

display image forming means, including a liquid crystal display panel provided with a first polarizing plate and a second polarizing plate attached respectively to one and the other surfaces of a liquid crystal display cell, for forming a display image to be projected on a projection screen by transmitting light from the illumination source for image display use through the liquid crystal display panel, the first polarizing plate arranged opposite to the illumination source for image display use;

luminescent spot image forming means, having an illumination source for signal input use, for forming a luminescent spot image by projecting light from the illumination source for input use on the projection screen;

image focusing means, provided between the display image forming means and the projection screen, for focusing a display image on the projection screen upon receiving light from the display image forming means, and focusing reflection light received from the projection screen on the display image forming means;

a polarizing beam splitter which reflects light in a direction of polarization different from a direction of polarization of the second polarizing plate upon receiving light emitted from the image focusing means to the liquid crystal display panel;

luminescent spot image detecting means for detecting the luminescent spot image upon receiving light reflected by the polarizing beam splitter; and

display control means, responsive to a detection signal representing the luminescent spot image detected from the luminescent spot image detecting means, for controlling a display image forming operation of the liquid crystal display panel based on the detection signal.

10. A projection display apparatus as claimed in claim 9, further comprising:

reception image focusing means, provided between the polarizing beam splitter and the luminescent spot image detecting means, for focusing an image received from the polarizing beam splitter through reduction on the luminescent spot image detecting means.

11. A projection display apparatus as claimed in claim 9, wherein the illumination source of the luminescent spot image forming means is an illumination source which emits a light of which direction of polarization is random.

12. A projection display apparatus as claimed in claim 10, wherein the illumination source of the luminescent spot image forming means is an illumination source which emits a light of which direction of polarization is random.

13. A projection display apparatus as claimed in claim 9, wherein the illumination source of the luminescent spot image forming means is an illumination source which emits a circularly polarized light.

14. A projection display apparatus as claimed in claim 10, wherein the illumination source of the luminescent spot image forming means is an illumination source which emits a circularly polarized light.

24. A projection display apparatus as claimed in claim 9, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

25. A projection display apparatus as claimed in claim 10, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

26. A projection display apparatus as claimed in claim 11, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

27. A projection display apparatus as claimed in claim 12, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

28. A projection display apparatus as claimed in claim 13, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

15. A projection display apparatus comprising:

an illumination source for image display use;

display image forming means, including a liquid crystal display panel provided with an image display polarizing plate attached to one surface of a liquid crystal display cell, for forming a display image to be projected on a projection screen by transmitting the light from the illumination source for image display use through the liquid crystal display panel, the image display polarizing plate arranged opposite to the illumination source for image display use;

luminescent spot image forming means, having an illumination source for signal input use, for forming a luminescent spot image by projecting light from the illumination source for input use on the projection screen;

image focusing means, provided between the display image forming means and the projection screen, for focusing a display image on the projection screen upon receiving light from the display image forming means, and focusing reflection light received from the projection screen on the display image forming means;

a polarizing beam splitter which is provided between the liquid crystal display panel and the image focusing means, and operates to polarize a display image light from the liquid crystal display panel in a specified direction of polarization, output the resulting polarized light to the image focusing means, receive light emitted from the image focusing means to the liquid crystal display panel, and reflect a light component in a direction of polarization different from the specified direction of polarization;

luminescent spot image detecting means for detecting the luminescent spot image upon receiving light reflected by the polarizing beam splitter; and

display control means, responsive to a detection signal representing the luminescent spot image detected from the luminescent spot image detecting means, for controlling a display image forming operation of the liquid crystal display panel based on the detection signal.

30. A projection display apparatus as claimed in claim 15, comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

16. A projection display apparatus comprising:

display image forming means for forming a display image to be projected on a projection screen;

luminescent spot image forming means, having an illumination source for signal input use, for forming a luminescent spot image by projection light form the illumination source for input use on the projection screen;

image focusing means, provided between the display image forming means and the projection screen, for focusing a display image on the projection screen upon receiving light from the display image forming means, and receiving reflection light from the projection screen;

luminescent spot image extracting means, provided between the image focusing means and the display image forming means, for extracting light from the luminescent spot image out of a received incident light from the image focusing means;

luminescent spot image detecting means for detecting the luminescent spot image upon receiving the light from the luminescent spot image extracted by the luminescent spot image extracting means;

display control means, responsive to a detection signal representing the luminescent spot image detecting by the luminescent spot image detecting means, for controlling a display image forming operation of the display image forming means based on the detecting signal; and

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light output from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

19. A projection display apparatus as claimed in claim comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

29. A projection display apparatus as claimed in claim comprising:

reference image forming means, provided in a specified position relative to the display image forming means, for outputting a reference light including a light different from the light outputted from the luminescent spot image forming means to the projection screen, thereby forming on the projection screen a reference image which has a fixed relative positional relation with the display image formed by the display image forming means.

31. A projection display apparatus comprising:

display image forming means for forming a color display image to be projected on a projection screen;

luminescent spot image forming means, having an illumination source for signal input use, for forming a luminescent spot image by projecting light from the illumination source for input use on the projection screen;

color separating means for separating light from a projecting source providing light to said display image forming means into constituent color portions and delivering said constituent color portions to said display image forming means at differing angles thereto;

image focusing means, provided between the display image forming means and the projection screen, for focusing a display image on the projection screen upon receiving light from the display image forming means, and receiving reflection light from the projection screen;

luminescent spot image extracting means for extracting light from the luminescent spot image out of a received incident light from the image focusing means;

luminescent spot image detecting means for detecting the luminescent spot image upon receiving the light from the luminescent spot image extracted by the luminescent spot image extracting means; and

display control means, responsive to a detection signal representing the luminescent spot image detecting by the luminescent spot image detecting means, for controlling a display image forming operation of the display image forming means based on the detection signal.

32. The projection display apparatus as claimed in claim 31, wherein said color separating means includes dichroic mirrors, one for each constituent color portion for selectively reflecting only a respective constituent color portion, said dichroic mirrors being inclined with respect to one another.

33. The projection display apparatus as claimed in claim 31, wherein said display image forming means includes portions thereof which are designated for a particular constituent color, further comprising an array of lenses which focus the constituent colors to respective portions of said display image forming means.

34. The projection display apparatus as claimed in claim 31, further comprising a Fresnel lens between said display image forming means and said image focusing means.

35. A projection display apparatus comprising:

display image forming means for forming a color display image to be projected on a projection screen;

luminescent spot image forming means, having an illumination source for signal input use, for forming a luminescent spot image by projecting light from the illumination source for input use on the projection screen;

luminescent spot image color selecting means for varying a color of the luminescent spot image on the projection screen;

switching means for selecting the color of the luminescent spot image on the projection screen, thereby controlling said luminescent spot image color selecting means;

image focusing means, provided between the display image forming means and the projection screen, for focusing a display image on the projection screen upon receiving light from the display image forming means, and receiving reflection light from the projection screen;

luminescent spot image extracting means for extracting light from the luminescent spot image out of a received incident light from the image focusing means;

luminescent spot image detecting means for detecting the luminescent spot image upon receiving the light from the luminescent spot image extracted by the luminescent spot image extracting means; and

display control means, responsive to a detection signal representing the luminescent spot image detecting by the luminescent spot image detecting means, for controlling a display image forming operation of the display image forming means based on the detection signal.

36. The projection display apparatus as claimed in claim 35, wherein said luminescent spot image color selecting means include a light source emitting light of different colors and said switching means controls an illumination state of said light source.

37. The projection display apparatus as claimed in claim 36, wherein said light source includes a plurality of light emitters, each emitting light at a different color and said switching means selects on and off states of said plurality of light emitters.