Data entry control panel

• US 5,225,818 A
• Filed: 11/26/1990
• Issued: 07/06/1993
• Est. Priority Date: 11/26/1990
• Status: Expired due to Fees

• Current Assignee: Data Entry Products, Inc. (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Data Entry Products, Inc. (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Lee, Weng-Kai K., Rivera, David A., Myles, Kevin M., Berman, H. Michael, Willis, Paula C.
• Primary Examiner(s): Weldon, Ulysses
• Assistant Examiner(s): Mengistu, Amare
• Application Number:
  US07/617,991
• Time in Patent Office: 953 Days
• Field of Search: 200/313, 200/314, 200/317, 200/512, 200/513, 340/711, 340/762, 340/784
• US Class Current: 345/170
• CPC Class Codes: H01H 13/7006 comprising a separate movable contact element for each switch site, all other elements being integrated in layers
• CPC Class Codes: H01H 13/705 characterised by construction, mounting or arrangement of operating parts, e.g. push-buttons or keys
• CPC Class Codes: H01H 2205/026 Adhesive sheet
• CPC Class Codes: H01H 2213/01 with internal pressure of other switch sites
• CPC Class Codes: H01H 2219/014 LED
• CPC Class Codes: H01H 2219/056 Diffuser; Uneven surface
• CPC Class Codes: H01H 2219/0622 only an illuminated ring around keys
• CPC Class Codes: H01H 2227/002 Layer thickness
• CPC Class Codes: H01H 2227/02 Vent opening
• CPC Class Codes: H01H 2229/028 Adhesive
• CPC Class Codes: H01H 2229/032 Screw
• CPC Class Codes: H01H 2239/008 Static electricity considerations

Abstract

The thin section data display control panel of the present invention includes a graphic overlay, a diffuser block affixed to the graphic overlay and light emitting diodes surface mounted on a printed circuit board for providing localized sources of light to be transmitted through the diffuser block to the overlay. The graphic overlay is generally opaque, but has translucent areas through which the illumination shines. An overlay reflective portion on a diffuser side of the overlay reflects light back into the diffuser, except in areas adjacent to the translucent areas of the overlay. The diffuser block is affixed to the graphic overlay and is generally transparent for transmitting the light from the light emitting diodes. Block reflective surfaces on the perimeter edges of the diffuser block prevent light from exiting through the edges. Matte surfaces of the diffuser block adjacent the graphic overlay and adjacent the printed circuit board scatter the light transmitted from the light emitting diodes. The light emitting diodes provide a plurality of localized sources of light which is scattered within the diffuser block and thereby provide relatively uniform back lighted illumination to the translucent portions of the graphic overlay. The light emitting diodes are partially received within a recessed portion of the diffuser block. An electrostatic discharge shield, adjacent the printed circuit board, having a reflective metallic surface reflects light not transmitted through the translucent portions back into the diffuser block.

Claims

1. A thin data display control panel comprising:

a graphic overlay of generally opaque hue but having translucent areas passing through a most thin dimension of said overlay, and generally having an overlay reflective portion on a diffuser side of said overlay, said reflective area not contiguous to said translucent areas, said overlay having a distal side opposite to said diffuser side and generally parallel to said diffuser side;

a diffuser block affixed to said graphic overlay so that said diffuser side of said overlay is adjacent to a graphic side of said block, said diffuser block being generally transparent but having a first matte diffusing surface on said graphic side of said block through which surface light is transmitted towards said graphic overlay opposite an illumination side parallel to said graphic side; and

illumination assembly means for providing a plurality of localized sources of light which are transmitted through said diffuser block in a diffuse manner and evenly illuminate only the translucent portions of said overlay when viewed from the distal side of said overlay.

2. The data display control panel of claim 1 further including:

said block having a block reflective surface being at least a semi-reflective coating generally adjacent at least perimeter edges joining said graphic and illumination sides of said block.

3. The data display control panel of claim 1 wherein said diffuser block further includes a second matte diffusing surface on said illumination side of said block.

4. The data display control panel of claim 1 further including:

a printed circuit board to which said illumination assembly means is mounted; and

wherein

said illumination assembly means is a plurality of light emitting diodes.

5. The data display control panel of claim 4 wherein

said light emitting diodes each have a half angle off axis intensity at which a luminous intensity emitted by each said diodes falls to one half the axial intensity in excess of thirty degrees.

6. The data display control panel of claim 5 wherein said half angle is about seventy degrees and luminous intensity is about two milli-candela.

7. The data display control panel of claim 6 wherein said light emitting diodes are surface mounted to said printed circuit board.

8. The data display control panel of claim 4 further including:

an illumination reflecting means adjacent said printed circuit board for reflecting light towards said diffuser block.

9. The data display control panel of claim 8 wherein:

said illuminating reflecting means is aluminum foil carried on a film placed between an illumination portion of said light emitting diodes and a front side of said printed circuit board nearest to said diffuser block;

said light emitting diodes each are surface mounted to said front side and said diode have a half angle off axis intensity at which a luminous intensity emitted by each said diodes falls toone half the axial intensity in excess of thirty degrees.

10. The data display control panel of claim 3 wherein

said overlay reflective portion is a metallic ink.

11. The data display control panel of claim 2 wherein

said block reflective surface is white ink applied to the perimeter edges of said block with a coat of black ink overlying said white ink;

and

said overlay reflective portion is a metallic ink.

12. The data display control panel of claim 1 wherein said illumination side of said diffuser block further includes:

a base portion; and

a recessed portion closer to said graphic side than said base portion is, which recessed portion partially receives said illumination assembly means.

13. The data display control panel of claim 4 further including

a plurality of switches arranged in arrays;

and wherein said illumination side of said diffuser block further includes,

a base portion adjacent a front side of said printed circuit board including base perimeter portions adjacent perimeter edges of said diffuser block and base key portions adjacent said switches; and

a recessed portion spaced away from said front side of said printed circuit board and closer to said graphic side than said base portion is, which recessed portion partially receives said light emitting diodes.

14. The data display control panel of claim 13 wherein said base key portions are peninsulas joined to said base perimeter portions.

15. The data display control panel of claim 14 further including:

a liquid crystal display assembly;

a LCD window to the interior of said perimeter edges of said diffuser block, said window having window edges extending between said graphic and illumination sides, said window edges and said perimeter edges having a block reflective surface, said LCD window partially receiving said liquid crystal display assembly; and

said graphic overlay having a transparent portion through which said liquid crystal display is viewable.

16. A data display control panel comprising:

a backseal film being generally dirt impermeable;

a printed circuit board including foil for switch contacts, and power leads on a front side of said printed circuit board, and having at least one through breather- hole in the vicinity of each switch contact termination, said backseal film adhered to a back side of said printed circuit board to form a dirt impermeable reservoir;

a dome switch contact being dome shaped and having the dome interior communicating with at least one breather hole;

a domeseal film affixed to said printed circuit board to positively located said dome switch on said front of said printed circuit board;

a plurality of light emitting diodes surface mounted to said front of said printed circuit board and emitting light in a emitting direction normal to said front and away from said printed circuit board;

electrostatic discharge shield foil means for dissipating electric charge away from said switches and reflecting light, said shield foil means including a film carrier carrying conductive light reflecting foil, said shield foil means generally passing over said domeseal film to the side away from said printed circuit board but excised in the area of each of said plurality of light emitting diodes to allow light to be transmitted in said emitting direction;

a diffuser block having a graphic side, and an illumination side and perimeter edges joining said graphic and illumination sides, said illumination side facing said front of said printed circuit board and receiving emitted light from said light emitting diodes, said illumination side including a base portion closely adjacent to said front of said printed circuit board and a recessed portion spaced away from said base portion in the emitting direction, said graphic side generally having a matte diffusing surface, said illumination side generally having a matte diffusing surface at least on said recessed portion, said block having a block reflective surface on said edges being a white coat of white ink and said white coat receiving a black coat of black ink, said diffuser block defining a plurality of communication orifices between said graphic and illumination sides, said diffuser block affixed to said printed circuit board;

a switch plunger occupying one of said communication orifices located adjacent said dome switch and extending at least beyond said graphic side in the emitting direction, said plunger being generally transparent; and

a graphic overlay affixed to said graphic side of said diffuser block, said overlay being generally opaque but having translucent portions illuminated by light generated by said light emitting diodes and passing through said diffuser block, said overlay selectively reflecting and receiving light transmitted through said diffuser block at a diffuser side of said overlay by generally having a diffuser reflective surface on said diffuser side except in a area adjacent said translucent portions so that light is only transmitted through said overlay in the translucent portions to be viewable from a distal side opposite said diffuser side and light not transmitted through said overlay is trapped among said diffuser reflective surface, said conductive light reflective foil and said block reflective surface.

17. An back lighted data control panel comprising:

a display graphic overlay which is partially translucent in preselected viewing areas, said overlay having a display surface perceptible to a viewer and a diffuser surface;

a diffuser plate having a first display surface closest to said display graphic overlay and a second illumination surface;

a plurality of illumination sources of relatively low intensity disposed to said second illumination surface side of said diffuser plate;

a graphic reflector interposed between said display graphic overlay and said diffuser plate reflecting light back into said plate which is not transmitted through the translucent areas of said graphic overlay; and

an illumination reflector interposed between said diffuser plate and said plurality of illumination sources reflecting light back into said diffuser plate,

whereby the illumination levels at the display surface of said graphic overlay are relatively uniform while avoiding glare in a relatively thin cross section through said diffuser as a result of the multiple reflections through said diffuser.

18. The data control panel of claim 17 wherein said diffuser plate has a first display matte surface closest to said display graphic overlay.

19. The date control panel of claim 18 wherein said diffuser has a second illumination matte surfaces closest to said illumination sources.

20. The data control panel of claim 19 further including a first display matte surface closest to said display graphic overlay.

21. The data control panel of claim 20 wherein light is transmitted from said graphic reflector through said first graphic matte surface into said diffuser plate, from aid diffuser plate through said second illumination matte surface to said illumination reflector, where the light is reflected through said second illumination matte surface through said diffuser and out through said first graphic matte surface plate.