Integrated front projection system

• US 6,179,426 B1
• Filed: 03/03/1999
• Issued: 01/30/2001
• Est. Priority Date: 03/03/1999
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Rodriguez, Ernesto M. Jr., Vanderwerf, Dennis F.
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US09/261,715
• Time in Patent Office: 699 Days
• Field of Search: 353/79, 353/39, 353/69, 353/70, 353/119, 353/122, 248/917, 248/918, 248/919, 248/920
• US Class Current: 353/69
• CPC Class Codes: G03B 21/10 Projectors with built-in or built-on screen
• CPC Class Codes: G03B 21/147 Optical correction of image distortions, e.g. keystone
• CPC Class Codes: G03B 21/2053 Intensity control of illuminating light controlled by video signal processing H04N5/74 or H04N9/31
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3185 Geometric adjustment, e.g. keystone or convergence optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A front projection display system that integrates an optical engine, having control and power supply electronics, and a dedicated projection screen to provide a compact video display device. The projection engine is coupled to a high gain projection screen, having an optimized reflection pattern to give optimum optical performance in ambient light and viewing angle sensitive environments. Components of the projection engine are modularly placed in a retractable arm, pivotally connected to the screen. The arm offers precise registration to the screen apparatus and thus repeatably precisely aligns optically and mechanically to the screen. The projection wall system has an open projection position and a closed storage position. Use of a radically offset projection head having matching keystone correction features allows the arm to protrude above the head of the presenter and offer a sharp and unobtrusive projection zone.

Claims

1. An integrated front projection display comprising:

a) a front projection screen;

b) a movable arm coupled to the flat projection screen, the arm having a storage position and a projection position; and

c) a front projection head coupled to the arm, wherein when the arm is in the projection position, the front projection head is at a predetermined position with respect to the front projection screen

wherein the projection head includes projection optics having;

a mechanical off-axis keystone correction compensation greater or approximately equal to 22°

,

a throw distance of at most 800 mm, and

a throw-to-screen diagonal ratio of at most 1.

2. The front projection display of claim 1,

a) wherein the front projection screen has a generally flat surface, the generally flat surface defining a horizontal axis and a vertical axis,

b) the front projection screen having a vertically graduated reflection distribution, wherein light rays emanating from the projection position generally are reflected by the projection screen in a preselected direction.

3. The front projection display of claim 2, wherein the light rays generally are reflected in a normal direction with respect to the vertical axis.

4. The front projection display of claim 2, wherein the light rays generally are reflected along an illumination spread with respect to the horizontal axis.

5. The front projection display of claim 1, further comprising an electronic module and an imaging module, wherein the imaging module is modularly placed separately from the electronic modules.

7. The front projection display of claim 1, further comprising a light source and a flexible illumination waveguide, wherein the projection head includes imaging components optically coupled to the light source by the flexible illumination waveguide.

16. The integrated front projection display of claim 1, further comprising:

a) a controlled light distribution front projection screen; and

b) a front projection head integrally coupled to the projection screen, wherein the front projection head has a predetermined projection position with respect to the screen, and the screen is optically tuned to receive and reflect light rays emanating from the projection head at the projection position.

17. The front projection display of claim 16,

a) wherein the screen has a generally flat surface, the generally flat surface defining a horizontal axis and a vertical axis,

b) the front projection screen having a vertically graduated reflection distribution, wherein the light rays emanating from the projection head generally are reflected by the projection screen in a preselected direction.

18. The front projection display of claim 17, wherein the light rays generally are reflected in a normal direction with respect to the vertical axis.

19. The front projection display of claim 17, wherein the light rays generally are reflected along an illumination spread with respect to the horizontal axis.

20. The front projection display of claim 16, further comprising a swiveling arm coupling the front projection screen to the front projection head.

21. The front projection display of claim 20, further comprising an electronic module and an imaging module, wherein the imaging module is modularly placed separately from the electronic module.

6. An integrated front projection display comprising:

c) a front projection screen;

d) a movable arm coupled to the flat projection screen, the arm having a storage position and a projection position; and

e) a front projection head coupled to the arm, wherein when the arm is in the projection position, the front projection head is at a predetermined position with respect to the front projection screen;

f) an electronic module and an imaging module, wherein the imaging module is modularly placed separately from the electronic module, and wherein the imaging module is placed inside the projection head and the electronic module is placed in the movable arm.

8. An integrated front projection display comprising:

a) a front projection screen;

b) a movable arm coupled to the flat projection screen, the arm having a storage position and a projection position; and

c) a front projection head coupled to the arm, wherein when the arm is in the projection position, the front projection head is at a predetermined position with respect to the front projection screen;

d) an electronic module enclosed by a honeycomb structure;

e) further comprising a cooling fan producing a cooling current, wherein the movable arm has an elongated hollow structure, and the honeycomb structure directs the cooling current to flow through the length of the hollow structure.

9. The front projection display of claim 8, wherein the honeycomb is a heat exchanger and the heat generated by the projector is dissipated by convection by the cooling current.

10. An integrated front projection display comprising:

b) a controlled light distribution front projection screen;

b) a front projection head integrally coupled to the projection screen, wherein the front projection head has a predetermined projection position with respect to the screen, and the screen is optically tuned to receive and reflect light rays emanating from the projection head at the projection position;

c) a swiveling arm coupling the front projection screen to the front projection head;

d) an electronic module and an imaging module, wherein the electronic module is enclosed by a honeycomb structure; and

e) a cooling fan producing a cooling current, wherein the swiveling arm has an elongated hollow structure, and the honeycomb structure directs the cooling current to flow through the length of the hollow structure.

11. An integrated front projection display comprising:

a) a front projection screen;

b) a movable arm coupled to the flat projection screen, the arm having a storage position and a projection position; and

c) a front projection head coupled to the arm, wherein when the arm is in the projection position, the front projection head is at a predetermined position with respect to the front projection screen;

d) an electronic module enclosed by a honeycomb structure;

e) wherein the honeycomb structure includes a plurality of cells and wherein the size, orientation, and wall thickness of the cells are tuned to attenuate specific electromagnetic wavelengths.

12. An integrated front projection display system comprising:

a) a planar projection screen formed on a front surface of a frame,

b) a movable arm hingedly connected at a first end to the frame, the arm being movable between a storage position and a projection position, and

c) a projection head mounted on a second end of the movable arm such that it does not substantially obstruct the view of the projection screen when the arm is in the projection position, the projection head including a keystone correction mechanism for projecting a corrected image onto the projection screen when the arm is in the projection position.

13. A digital annotation system including the front projection display of claim 12.

14. A video-conferencing system including the front projection display of claim 12.

15. The front projection display of claim 12, further including a CPU.

31. The front projection display system of claim 12,

a) the projection head having, in the projection position, a predetermined source point location for projected light rays;

b) the front projector screen defining a horizontal axis and a vertical axis, the front projector screen comprising a plurality of optical elements distributed across the projector screen, wherein each of the optical elements is optically aligned with the source point location to receive the projected light rays at an expected angle of incidence and to reflect the projected light rays at a predetermined desired angle of reflection.

32. The front projection display system of claim 31, wherein the projection screen further comprises

a) a multi-layer material construction having a first linear Fresnel element layer,

b) a second linear Fresnel element layer and

c) a reflector, the first linear Fresnel, the second linear Fresnel and the reflector arranged sequentially;

d) wherein the first linear Fresnel layer includes a plurality of horizontal grooves having a vertically graduated pattern corresponding to the vertical component of the expected angle of incidence of the projected light rays at each horizontal groove and the vertical component of the angle of incidence of the desired angle of reflection, each horizontal groove corresponding to a row of the optical elements.

33. The front display system of claim 32,

a) wherein the second linear Fresnel element includes a plurality of vertical grooves having a horizontal pattern corresponding to the horizontal component of the expected angle of incidence of the projected light rays at each vertical groove and the horizontal component of the angle of incidence of the desired angle of reflection, each vertical groove corresponding to a column of the optical elements.

34. The front display of claim 33, wherein the reflector includes a reflection pattern.

22. An integrated front projection display comprising:

a) a controlled light distribution front projection screen;

b) a front projection head integrally coupled to the projection screen, wherein the front projection head has a predetermined projection position with respect to the screen, and the screen is optically tuned to receive and reflect light rays emanating from the projection head at the projection position;

c) a swiveling arm coupling the front projection screen to the front projection head; and

d) an electronic module and an imaging module, wherein the imaging module is modularly placed separately from the electronic module wherein the imaging module is placed inside the projection head and the electronic module is placed in the swiveling arm.

23. The front projection display of claim 22, wherein the electronic components are enclosed by a honeycomb structure.

24. A front projection system comprising:

a) power supply and control electronic components, the electronic components radiating electromagnetic waves;

b) optical components, wherein the electronic components are modularly separated from the optical components; and

c) a honeycombed structure enclosing the electronic components, the honeycomb structure having a plurality of hexagonal cells oriented to collect the electromagnetic waves and having a size less than the expected wavelength of the electromagnetic waves.

25. An integrated front projection display comprising:

a) a controlled light distribution front projection screen;

b) a front projection head integrally coupled to the projection screen, wherein the front projection head has a predetermined projection position with respect to the screen, and the screen is optically tuned to receive and reflect light rays emanating from the projection head at the projection position;

c) a swiveling arm coupling the front projection screen to the front projection head;

d) an electronic module and an imaging module, wherein the electronic module is enclosed by a honeycomb structure; and

e) wherein the honeycomb is a heat exchanger and the heat generated by the projector is dissipated by convection by the cooling current.

26. The front projection display of claim 25, further comprising a light source and a flexible illumination waveguide, wherein the projection head includes imaging components optically coupled to the light source by the flexible illumination waveguide.

27. An integrated front projection display comprising:

a) a controlled light distribution front projection screen;

b) a front projection head integrally coupled to the projection screen, wherein the front projection head has a predetermined projection position with respect to the screen, and the screen is optically tuned to receive and reflect light rays emanating from the projection head at the projection position;

c) wherein the projection head includes a projection optics having;

i) a mechanical off-axis keystone correction compensation greater or approximately equal to 22°

,

ii) a throw distance of at most 800 mm,

iii) a throw-to-screen diagonal ratio of at most 1.

28. A digital annotation system including the front projection display of claim 27.

29. A video-conferencing system including the front projection display of claim 27.

30. A front projection system comprising:

a) a front projection screen; and

b) a front projector device integrally coupled to the projection screen, the projector device having;

i) a mechanical off-axis keystone correction compensation greater or approximately equal to 22°

,

ii) a throw distance of at most 800 mm,

iii) a throw-to-screen diagonal ratio of at most one.

35. An integrated front projection display system comprising:

a) a planar projection screen formed on a front surface of a rigid frame, the screen including means for reflecting light from the screen in a preselected spatial distribution;

b) a movable arm hingedly connected at a first end to the rigid frame, the arm being movable between a storage position and a projection position, the arm further comprising means for moving the arm between said storage and projection positions and for retaining the arm at each of said positions; and

c) a projection head mounted on a second end of the movable arm such that it does not substantially obstruct the view of the projection screen when the arm is in the projection position, the projection head including means for providing an image to be displayed, means for focusing the image onto the projection screen, and means for correcting the keystone effect in the projected image when the arm is in the projection position.