Writable disk sign

• US 6,220,723 B1
• Filed: 04/20/1999
• Issued: 04/24/2001
• Est. Priority Date: 11/17/1997
• Status: Expired due to Fees

• Current Assignee: Mark IV Industries Corporation
• Original Assignee: Mark IV Industries Corporation
• Inventors: Freeman, Timothy A., Tijanic, Veso S.
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Alavi, Ali
• Application Number:
  US09/294,314
• Time in Patent Office: 735 Days
• Field of Search: 362/812, 362/802, 362/252, 362/800, 362/249, 362/277, 362/240, 405/46, 404/77, 404/79
• US Class Current: 362/240
• CPC Class Codes: G09F 9/375 the position of the elements being controlled by the application of a magnetic field
• CPC Class Codes: Y10S 362/80 Light emitting diode
• CPC Class Codes: Y10S 362/802 Position or condition responsive switch
• CPC Class Codes: Y10S 362/812 Signs

Abstract

An array of disks facing a viewing direction is composed of disks rotatable about an axis approximately perpendicular to the viewing direction between alternating orientations where light and dark surfaces are respectively displayed in the viewing direction. There is provided a row of LEDs located forwardly of the array and out of the normal viewing path located to illuminate the disks of said array. Masking means prevents direct illumination from said LED'"'"'s being visible in the viewing direction. In a further variant the disks'"'"' light surfaces contain a fluorescent component and the LEDs are selected to provide radiation including UV spectra.

Claims

1. A writable disk sign comprising:

an array of disks each defining a median plane and a viewing direction from intended viewing locations forwardly of said plane, each said disk being rotatable about an axis approximately transverse to the viewing direction, between alternate orientations where bright and dark surfaces are respectively displayed in the viewing direction;

a plurality of LEDs located forwardly of the plane of the array and outside the array as viewed in the viewing direction, said LEDs being located to illuminate the then forward side of the disks in said array; and

masking means for preventing direct illumination from said LEDs travelling to said viewing locations.

2. A writable disk sign according to claim 1 wherein the color of radiation from said LEDs approaches the of said bright surfaces.

3. A writable disk sign according to claim 1 having opposite sides and opposite ends as viewed in the viewing direction and having a plurality of LEDs on opposite sides of said array as viewed in the viewing direction.

4. A writable disk sign according to claim 2 having pluralities of LEDs on opposite sides of said array as viewed in the viewing direction.

5. A writable disk sign according to claim 3 wherein each of said pluralities comprises a first set of LEDs arranged to direct radiation toward an outer region of said array near said first set and a second set of LEDs arranged to direct radiation toward a central area between opposite side outer areas.

10. A writable disk sign according to claim 2 wherein each of said LEDs is combined with a lens to form a lamp and said lamp is mounted on a printed circuit board.

6. A writable disk sign comprising:

an array defining a viewing direction, said array being composed of disks rotatable to selectively present opposite bright or dark surfaces to an intended viewing location;

a housing for said array visible from the intended viewing location;

a group of LEDs located on at least one side of said array as viewed from said viewing location, and directed to illuminate the forward facing surfaces of said disks; and

a masking extent located to block radiation from said LEDs going directly to said viewing location, said masking extent being outside said array as viewed from said viewing location.

7. A writable disk sign according to claim 6 wherein the color of radiation from said LEDs is close to the color of said bright surfaces.

8. A writable disk sign according to claim 6 wherein there are groups of LEDs on each side of the array and wherein each of said groups comprises a first set of LEDs arranged to direct radiation toward an outer area of said array near said fist set and a second set of LEDs arranged to direct radiation toward a central area between opposite side outer areas.

9. A writable disk sign according to claim 7 wherein there are groups of LEDs on each side of the array and wherein each of said groups comprises a first set of LEDs arranged to direct radiation toward an outer area of said array near said first set and a second set of LEDs arranged to direct radiation toward a central area between opposite side outer areas.

11. A writable disk sign according to claim 6 wherein each of said LEDs is combined with a lens to form a lamp and said lamp is mounted on a printed circuit board.

12. A writable disk sign comprising:

a number of display elements forming an array, each display element controllably movable between a first and a second position where, respectively, first and second contrasting surfaces are displayed to a viewing location, said first contrasting surface having a fluorescent component; and

LEDs located outside the array as viewed from the viewing location to shine on those surfaces then displayed to the viewing location;

wherein radiation from said LEDs contains components to cause fluorescence when incident on said first contrasting surface.

13. A writable disk sign according to claim 12 wherein said number of display elements form an array of rows and columns when viewed from the viewing location.

14. A writable disk sign according to claim 12 further comprising masking means for preventing radiation from being radiated directly to the viewing location.

15. A writable disk sign according to claim 12 wherein said first surface comprises a mixture of light and fluorescent material.

16. A writable disk sign according to claim 12 wherein at least some of said LEDs emit radiation containing a substantial deep blue component and an ultraviolet component.

17. A writable disk sign according to claim 12 wherein at least some of said LEDs radiate a color closely approaching white.

18. A writable disk sign according to claim 12 wherein said LEDs radiate radiation consisting essentially of ultraviolet light.

19. A writable disk sign according to claim 12 wherein the semiconductors for said LEDs produce a white color containing a substantive amount of ultraviolet rays.

20. A writable disk sign according to claim 12 wherein said disks are angled toward said LEDs when in said first position to increase exposure of said first surfaces to LED rays, and away from said LEDs when in said second position to reduce exposure of said second surfaces to LED rays, to increase the contrast between the first and second surfaces as viewed from the viewing location.

21. A writable disk sign according to claim 12 wherein the radiation from the LEDs is predominantly ultraviolet, the writable disk sign further comprising a filter forming part of each LED for blocking a large proportion of the rays from the visible spectrum.

22. A writable disk sign according to claim 12 wherein said first contrasting surfaces are light and said second contrasting surfaces are darker then said first contrasting surfaces.

23. A writable disk sign according to claim 12 wherein said first contrasting surfaces are yellow and said second contrasting surfaces are darker than said first contrasting surfaces.

24. A writable disk sign comprising:

an array of display elements, each display element having opposite first and second contrasting surfaces and being controllably movable between first and second positions wherein said first and second surfaces are respectively displayed toward a viewing location;

a fluorescent compound forming part of said first surface;

a plurality of LEDs arranged to illuminate those first and second surfaces displayed toward the viewing location, said LEDs emitting substantial radiation in the ultraviolet band.

25. A writable disk sign according to claim 24 including means masking said LEDs from the viewing location.

26. A writable disk sign comprising:

an array of display elements arranged in rows and columns, said display elements being movable between first and second positions, and displaying a first surface to a viewing location when in said first position and displaying a second surface to said viewing location when in said second position, said first surface including a fluorescent component;

a wall framing said array when viewed in the viewing direction located forwardly of said array; and

LEDs mounted to be masked from said viewer by said wall and arranged to radiate directly on the surfaces of elements in said array displayed to said viewing location, said LEDs providing ultraviolet radiation.

27. A writable disk sign according to claim 26 wherein said array is mounted on a first printed circuit board.

28. A writable disk sign according to claim 27 comprising a second printed circuit board mounted on said first printed circuit board and said LEDs are mounted on said second printed circuit board.

29. A writable disk sign according to claim 28 wherein one of said first and second printed circuit boards has mounting prongs and the other of said first and second printed circuit boards has complementary mounting sockets.

30. A writable disk sign according to claim 27 wherein said LEDs are located on a second printed circuit board.