Illuminated compact control surface

• US 4,642,627 A
• Filed: 03/13/1984
• Issued: 02/10/1987
• Est. Priority Date: 03/13/1984
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: General Electric Company
• Inventors: Hodsdon, Roy F.
• Primary Examiner(s): Brigance, Gerald L.
• Application Number:
  US06/589,000
• Time in Patent Office: 1,064 Days
• Field of Search: 340/711, 340/765, 340/365 R, 340/365 VL, 340/815.16, 340/818.17, 340/712
• US Class Current: 345/50
• CPC Class Codes: G06F 3/033 Pointing devices displaced or positioned by the user , e.g. mice, trackballs, pens or joysticks; Accessories therefor digitisers characterised by the transducing means G06F3/041
• CPC Class Codes: G06F 3/0489 using dedicated keyboard keys or combinations thereof

Abstract

A control surface for controlling the operation of an electronic apparatus includes a liquid crystal display device and a keypad. The liquid crystal display device selectively changes its light transmittance in response to electrical signals produced by the electronic apparatus in order to provide a visual indication viewable by a human viewer. A light source emits light. A first optical coupler including a specular surface and a light transmissive diffuser is disposed a predetermined distance from the liquid crystal display device. Ambient light passing through the liquid crystal display device strikes the specular surface and is reflected back through the display device toward the human viewer, illuminating indicia displayed by the display device. Light from the light source strikes the light diffuser at a high angle of incidence and is scattered toward the display device, illuminating the display device. A display driver (which coverts electrical signals produced by the electronic apparatus to driving signals suitable for driving the liquid crystal display device) is electrically connected to the display device with elastomeric zebra connectors. The liquid crystal display device, the light diffuser, the specular surface, the elastomeric connectors and the display driver are all disposed in a clear, weatherproof plastic cover. An opaque keypad is provided to control the operation of the electronic apparatus. The clear cover and the keypad are disposed in a housing. An opening (into which a lens is secured) is provided in the housing in proximity with the light source to direct some of the light emitted by the light source to floodlight the keypad.

Claims

1. A top-mounted control surface for a personal radio transceiver of the type including electrical circuits for establishing communications with a further physically-distinct communications device, said control surface including:

light source means, electrically coupled to said electrical circuits, for emitting light in response to an electrical signal applied thereto;

liquid crystal display means, electrically coupled to said electrical circuits and mounted on a top surface of said transceiver, for selectively changing light transmittance in response to electrical signals applied thereto;

a reflecting assembly mounted substantially parallel to the display means, said assembly including means defining a reflective surface, and a layer of transparent material disposed on said reflective surface between said reflective surface and said display means, said layer defining an irregular surface opposing said display means and spaced a predetermined distance therefrom;

keypad means, electrically connected to said electrical circuits, for controlling the operation of said electrical circuits in response to manipulation by a human operator, said keypad means at least in part defining said transceiver top surface;

said light source means directing a first portion of the light produced thereby into the space between said display means and said irregular surface to strike said irregular surface at a high angle of incidence; and

said light source means directing a second portion of the light produced by said light source means toward said keypad means to illuminate said keypad means.

2. A control surface as in claim 1 wherein said liquid crystal display means further includes:

first light transmissive plate means for transmitting light, said first light transmissive plate means defining a first surface;

second light transmissive plate means for transmitting light, said second light transmissive plate means defining a second surface;

liquid crystal means, disposed between said first and second light transmissive plate means and responsive to said electric signals, for transmitting light and for rotating the direction of polarization of said light transmitted through selected areas of said liquid crystal display means by 90°

;

first light polarizing means, disposed on said first surface, for polarizing said transmitted light to a first predetermined direction of polarization; and

second light polarizing means, disposed on said second surface, for transmitting light polarized to a second predetermined direction of polarization, said second predetermined direction rotated 90°

from said first predetermined direction.

3. A control surface as in claim 2 wherein

said control surface further includes display driver means, electrically connected to said electrical circuits, for converting said electrical signals to electrical driving signals driving said liquid crystal display means;

and

means for electrically connecting said liquid crystal display means with said display driver means.

4. A control surface as in claim 3 wherein said connecting means includes a resilient elastomeric strip disposed between said display means and said display driver means.

5. A control surface as in claim 4 wherein said liquid crystal display means further includes an optically transmissive conductive coating, disposed on a second surface of said first light transmissive plate means and on a second surface of said second light transmissive plate means, said resilient connecting strip contacting said conductive coating, said conductive coating also defining a plurality of respective segments on said second surface of said second light transmitting means, said segments defining a predetermined pattern, said conductive coating disposed on a substantial area of the second surface of said first light transmitting means, said conductive coating conducting said electrical driving signals to produce an electric field incident to said liquid crystal means, said liquid crystal means rotating the direction of polarization of said transmitted light where said electric field is present.

6. A control surface as in claim 5 wherein:

said predetermined pattern comprises two sets of seven respective segments, said segments of each said set defining the shape of the number 8; and

wherein said conductive coating also defines a plurality of pathways, each of said pathways electrically isolated from others of said pathways, each of said segments electrically connected to a different one of said pathways, said resilient strip connecting said pathways to said display driver means.

7. A control surface as in claim 4 wherein said resilient strip includes:

first and second strips of elastomeric material; and

a plurality of discrete electrical conductive elements disposed between said first and second strips.

8. A control surface as in claim 2 wherein said reflecting assembly scatters light produced by said light source means and striking said irregular surface at a high angle of incidence toward said first light transmissive plate means and specularly reflects toward said first light transmissive plate means ambient light incident to said first surface of said second light transmissive plate means and transmitted through said liquid crystal display means and striking said reflective surface at a low angle of incidence.

9. A control surface as in claim 1 wherein:

said control surface further includes housing means for housing said liquid crystal display means, said light source means and said first optical coupling means, said housing means including a first wall in proximity with said light source means, said first wall defining a first opening; and

said second optical coupling means comprises lens means, disposed in said first opening, for directing said second portion of said light toward said keypad means.

10. A control surface as in claim 9 wherein:

said control surface further comprises a printed circuit board a plurality of electrical pathways on a first surface thereof, said electrical pathways conducting a plurality of respective ones of said electrical signals; and

said keypad means is disposed on said printed circuit board, said keypad means including;

a sheet of non-conductive, resilient material disposed on said first surface of said printed circuit board;

means for defining a plurality of resilient, depressible molded hollow protrusion in said sheet, each of said protrusions defining a corresponding hollow; and

plural electrical contact means, one of said contact means fixedly disposed within each of said hollows, for electrically connecting together predetermined ones of said electrical pathways when an associated one of said protrusions is depressed.

11. A control surface as in claim 10 wherein each of said electrical contact means comprises a circular conductive carbon silicone pad.

12. A control surface as in claim 10 wherein said sheet comprises molded silicone rubber.

13. A control surface as in claim 10 wherein said protrusion defining means defines sixteen of said protrusions, each of said protrusions including means for defining a visible symbol.

14. A control surface as in claim 1 wherein said light source means comprises a single lamp.

15. A control surface as in claim 4 further comprising light transmissive cover means for aligning and captivating said light source means, liquid crystal display means, first optical coupling means, display driver means and resilient elastomeric strip.

16. A display for displaying indicia pertaining to the operation of a personal radio transceiver, said transceiver of the type including (a) a case comprising an elongated box having a top surface, a bottom surface and plural side surfaces, the length of at least one edge of each of said side surfaces exceeding the length of any of the edges of said top and said bottom surfaces, and (b) electronic circuit means, disposed within said case, for establishing communications with a further physically-distinct communications device, said display including:

light source means mounted to said case top surface for emitting light;

liquid crystal display means, having a viewing surface defining a portion of said top surface, said display means mounted to said case in a position displaced laterally from the position of said light source means and electrically connected to said electronic circuit means, for selectively changing light transmissivity in response to electrical signals applied thereto, said display means defining a further surface parallel to and opposing said viewing surface; and

light diffusing means, disposed on said case top surface and spaced a predetermined distance from said liquid crystal display means further surface, for receiving light emitted by said light source means at a high angle of incidence and for scattering said received light toward said liquid crystal display means in a direction substantially normal to said display means further surface.

17. An apparatus as in claim 16 wherein said liquid crystal display means further includes:

first light transmissive plate means for transmitting light, said first light transmissive plate means defining said viewing surface;

second light transmissive plate means for transmitting light, said second light transmissive plate means defining said further surface;

liquid crystal means, disposed between said first and second light transmissive plate means and responsive to said electric signals, for transmitting light and for rotating the direction of polarization of said light transmitted through selected areas of said liquid crystal display means by 90°

;

first light polarizing means, disposed on said viewing surface, for polarizing said transmitted light to a first predetermined direction of polarization; and

second light polarizing means, disposed on said further surface, for transmitting light polarized to a second predetermined direction of polarization, said second predetermined direction rotated 90°

from said first predetermined direction.

18. An apparatus as in claim 17 wherein

said apparatus further includes display driver means, electrically connected to said electronic circuit means, for converting said electrical signals to electrical display driving signals;

and

connecting means connected to said display drive means and said display means for applying said display driving signals to said display means and for spacing said display means said predetermined distance from said light diffusing means.

19. An apparatus as in claim 18 wherein said connecting means includes at least one resilient elastomeric zebra strip.

20. An apparatus as in claim 19 wherein said liquid crystal display means includes an optically transmissive conductive coating, disposed on a second surface of said first light transmissive plate means and on a second surface of said second light transmissive plate means, said conductive coating defining a plurality of respective segments on said second surface of said second light transmitting means, said segments defining a predetermined pattern, said conductive coating also disposed on a substantial area of the second surface of said first light transmitting means, said conductive coating conducting said electrical driving signals to produce an electric field incident to said liquid crystal means, said liquid crystal means rotating the direction of polarization of said transmitted light except where said electric field is not present.

21. An apparatus as in claim 20 wherein:

said predetermined pattern comprises two sets of seven respective segments, said segments of each said set defining the shape of the number 8; and

wherein said conductive coating a plurality of pathways, each of said pathways electrically isolated from others of said pathways, each of said segments electrically connected to a different one of said pathways, said connecting means connecting said pathways to said display driver means.

22. An apparatus as in claim 20 wherein said light diffusing means includes means for defining an irregular surface a predetermined distance from said liquid crystal display means.

23. An apparatus as in claim 22 wherein:

said light diffusing means comprises a third light transmissive plate, said irregular surface disposed on said third plate; and

said apparatus further comprises reflecting means, disposed on a second surface of said third plate, said second surface being substantially parallel to said irregular surface, for reflecting toward said first light transmissive plate means ambient light incident to said first surface of second light transmissive plate means and transmitted through said liquid crystal display means.

24. An apparatus as in claim 19 further comprising light transmissive cover means, for aligning and captivating said light source means, liquid crystal display means, display driver means and resilient strips.

25. In a personal communications device of the type including (a) a case comprising an elongated box having a top surface, a bottom surface and plural side surfaces, the length of at least one edge of each of said side surfaces exceeding the length of any of the edges of said top and said bottom surfaces and (b) electronic circuit means, disposed within said case, for establishing communications with a further physically-distinct communications device in accordance with control signals supplied thereto, an improvement comprising control surface means, disposed on said top surface and electrically coupled to said circuit means, for applying said control signals to said circuit means in response to manipulation thereof by a user, said control surface means including:

a printed circuit board mounted to said case and including a plurality of electrical pathway means, electrically connected with said electronic circuit means and disposed on at least a first surface of said printed circuit board, for carrying electrical signals;

a keypad including a sheet of non-conductive, resilient material encasing at least a portion of said printed circuit board first surface and defining a portion of said communications device top surface, said sheet defining a plurality of resilient, depressible molded hollow protrusions, each of said protrusions defining a corresponding hollow;

plural electrical contact means, one fixedly disposed within each of said hollows, for electrically connecting predetermined ones of said electrical pathway means together when an associated one of said protrusions is depressed;

liquid crystal display means electrically coupled to said printed circuit board pathway means and defining a further portion of said communications device top surface for selectively changing light transmissivity in response to electrical signals applied thereto;

a reflective surface disposed on said printed circuit board first surface;

a transparent plate having a surface disposed on said reflective surface, said transparent plate having a further, irregular surface;

means disposed on said printed circuit board for electrically connecting said electrical pathway means to said liquid crystal display means and for spacing said liquid crystal display means a predetermined distance from and opposing said transparent plate irregular surface; and

light source means, electrically connected to said printed circuit board pathway means and mounted on said printed circuit board first surface, for directing light toward said keypad and also toward said transparent plate irregular surface at high angles of incidence.

26. A personal radio communications device comprising:

a hollow rectangular case including first and third side walls parallel to one another, second and fourth side walls parallel to one another, said first wall being rigidly joined to said second and fourth walls, said third wall being rigidly joined to said second and fourth walls, a bottom wall joined at a bottom end of said case to each of said first through fourth side walls, edges of each said first through fourth side walls together defining a substantially rectangular opening at a top end of said case opposite said bottom end thereof;

electronic circuit means disposed in said hollow case for establishing communications with a remotely-located communications device;

a keypad assembly electrically coupled to said electronic circuit means, said keypad assembly including;

a printed circuit board, mounted to said case top end obstructing said rectangular opening, including means defining a plurality of electrical pathways on a first surface thereof, and

a sheet of flexible material, disposed on said printed circuit board first surface, said sheet including means defining an array of keys, each of said keys including conductor means for selectively connecting predetermined ones of said pathways together;

a display driving integrated circuit, disposed on said printed circuit board first surface and electrically coupled to pathways disposed on said printed circuit board first surface, for producing electrical display driving signals;

a reflective surface disposed on said display driving circuit;

a layer of transparent material having a surface disposed on said reflective surface, said layer defining a further, irregular surface;

a liquid crystal display;

connecting means, disposed between said printed circuit board first surface and said liquid crystal display and electrically coupled to said display driving circuit, for supporting said display a predetermined distance above and substantially opposing said irregular surface and for applying said electrical display driving signals to said display; and

light source means, mounted to said printed circuit board, for producing light and for directing said light into the space between said display and said irregular surface, said directed light striking said irregular surface at a high angle of incidence and scattering toward said display.

27. A device as in claim 26 further including a lens disposed on said case top end in proximity to said light source for directing a portion of the light produced by said light source means toward said sheet of flexible material.