MODULAR TOUCH SENSITIVE INDICATING PANELS WITH TOUCH AND LIGHT TRANSMISSIVE OVERLAY COVER MEMBRANE CONTAINING VISIBLE PRINTED INDICIA

• US 3,777,222 A
• Filed: 05/12/1972
• Issued: 12/04/1973
• Est. Priority Date: 05/12/1972
• Status: Expired due to Term

• Current Assignee: Thomas J. Harris
• Original Assignee: Thomas J. Harris
• Inventors: Harris, Thomas J.
• Primary Examiner(s): Schaefer, Robert K.
• Assistant Examiner(s): Tolin, Gerald P.
• Application Number:
  US05/252,822
• Time in Patent Office: 571 Days
• Field of Search: 340/365S 179/9K 235/145R 307/116 200/1R,1SA,1SE,46,159B,167A 317/11CB,11CE,112
• US Class Current: 341/26
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 2203/05 to avoid damage by deformation of layers
• CPC Class Codes: H01H 2207/004 Printed circuit tail
• CPC Class Codes: H01H 2209/002 Materials
• CPC Class Codes: H01H 2209/014 composed of different layers; Lubricant in between
• CPC Class Codes: H01H 2209/016 Protection layer, e.g. for legend, anti-scratch
• CPC Class Codes: H01H 2215/03 Sound
• CPC Class Codes: H01H 2217/016 Pressure reduction membrane; Spreader layer
• CPC Class Codes: H01H 2219/002 replaceable; adaptable
• CPC Class Codes: H01H 2219/008 Adhesive
• CPC Class Codes: H01H 2219/014 LED
• CPC Class Codes: H01H 2219/034 Coloured areas
• CPC Class Codes: H01H 2219/04 Attachments; Connections
• CPC Class Codes: H01H 2221/002 integral with membrane
• CPC Class Codes: H01H 2227/002 Layer thickness

Abstract

Presently described touch sensitive indicating panels have thin but durably constructed plastic overlay membranes serving to: (a) transmit touch actuation pressure to underlying elastic diaphragm switch contacts arrayed at selected points of a pre-dimensioned grid; (b) transmit rear projection light indications received through spaces between switch grid conductors from suitably positioned light sources; (c) transmit alphanumeric light indications from suitably located arrays of light sources; (d) allow viewing of fixed information behind panels through suitably located areas; (e) display permanent indicia of artwork and nomenclature designating touch sensing and rear projection sites and functions; and (f) complete a housing enclosure. Panels for various host systems (e.g. computers, peripheral terminals, etc.) are assembled in various shapes and function types from a limited inventory of modular touch switches and control circuits. In the switch modules crossed grids of spaced conductors, which are prefabricated on transparent flexible support films, have pairs of spaced parallel contact segments subject to flexure into contact at positions offset from the grid intersections. The grids have predetermined dimensions of intersection spacing and the offset contact pairs have specific design features for enhanced integrity and reliability of contact operation. Modular sensing circuits perform the functions of: scanning contacts of the panel switch modules for touch closure conditions; representing locations of closure conditions at predetermined locations; providing audible feedback (beep tone) of contact sensing, and translating sensed contact conditions into panel light indications and/or electrical control functions. Various arrangements are described for producing complex control and indicating effects based upon combinational sensing of particular contact sequences.

Claims

1. In a touch sensitive indicating panel containing an integral covering overlay membrane useful for transmitting touch pressure to a plurality of touch sensitive switches, the improvement comprising:

a pattern of predominantly opaque artwork incorporated in said overlay to designate;

a plurality of interspersed and interassociative touch sensing sites and light spot indicating sites;

said indicating sites comprising a first plurality of single spot indicating sites discretely offset from said touch sensing sites and a second plurality of multi-spot character image indicating sites discretely offset and distinguished from both said touch sites and said first plurality of indicating sites;

said indicating sites consisting of discrete areas subject to light transmission formed by transparent elements in said artwork;

a modular assembly of touch sensitive elastic switches comprising conductors retained on transparent eleastic support films separated by a transparent spacer film having voids at switch sites;

said switch sites aligned with centers of respective said touch sites of said overlay; and

modular means mounted for electrical sensing association with said touch switches and for light spot indicating association with said overlay indicating sites;

said means including first means for detecting and interpreting touch contact conditions of said switches, second means for producting discrete single spot light indications directed towards respective said single spot indicating sites of said overlay and third means for producing multi-spot character image light indications directed towards respective said multi-spot indicating sites of said overlay.

2. In an improved touch sensitive indicating panel according to claim 1 the further improvement of a narrow band light filter incorporated in the material of said overlay at least at said indicating sites;

with said second and third means adapted to produce light spots having spectral characteristics predominantly contained within said narrow band.

3. In an improved touch sensitive indicating panel according to claim 1, the further improvement of a gloss treated covering surface in said overlay useful to reduce specular reflection.

4. In an improved touch sensitive indicating panel according to claim 1, the further improvement wherein said switch assembly comprises:

perpendicular arrays of interfacing conductors supported on said films separated by said transparent spacer film, pairs of perpendicular said conductors on respective said support films hving paired elastic extension segments offset from the position at which the conductors cross;

said paired segments being parallel to each other and aligned with centers of respective said voids in said spacing film;

each said pair of segments thereby forming a switch subject to elastic contact engagement through said respective spacer void in response to touch pressure transferred through a respective said touch site of said overlay.

5. In an improved touch sensitive indicating panel according to claim 4, the further improvement oF:

a transparent stress easing film interposed between said switch assembly and overlay;

said stress easing film having voids located at predetermined positions relative to said voids in said spacer film to ease mechanical stresses on the individual segments of said pairs of extension segments at edges of said voids in said spacer film.

6. An improved touch sensitive indicating panel according to claim 4 wherein said switch assembly further comprises:

conductive connection between opposite ends of each said extension segment and the respective said array conductor providing alternate conduction paths useful to maintain electrical touch sensing continuity in the event of physical severance of the respective extension segment.

7. An improved touch sensitive indicating panel according to claim 4 wherein said switch assembly comprises extensions of said perpendicular conductors, said support films and spacing film forming a flexible bus connectible with said modular means.

8. In an improved touch sensitive indicating panel according to claim 7, the further improvement wherein said modular means comprises:

means for supplying scan pulses sequentially to successive conductors on one of said support films;

means for sensing transferral of said scan pulse to conductors on the other one of said support films conditional upon existence of touch contact engagement between segments of a said extension segment pair;

latch means associated with said sensing means for retaining toggle indications associated with sensing operations of said sensing means; and

means associated with said latch means for conditioning operations of said sensing means in respect to certain of said extension segment pairs upon conditions preserved in said latch means in respect to prior operations of other segment pairs.

9. A panel according to claim 8 wherein said latch means preserve conditions reserved for control of power conditioning of at least a portion of said sensing means and for control of touch sense response of said sense means to all but one of said extension segment pairs, and wherein said sensing means is responsive to said one segment pair to reverse said touch sense control condition of said latch means.

10. In an improved touch sensitive indicating panel according to claim 7, the further improvement wherein said moudlar means is connectible through multi-channel interfacing circuit means with host equipment;

said interfacing means including;

means for sensing sequential operations of particular said offset contact segment pairs in predetermined combinational groupings; and

means responsive to said sensing means for controlling said second means to produce multi-spot light indicating effects at selected said second indicating sites and control and input effects relative to selected channels of said interfacing means.

11. In an improved touch sensitive indicating panel according to claim 10, the further improvement wherein said interfacing means includes:

bypass control means capable of operating independently of said sensing means to control said means responsive to said sensing means.

12. In a touch sensitive indicating panel in combination:

a touch transmissive elastic overlay membrane formed out of transparent material containing a covering pattern of opaque artwork surrounding isolated areas of transparency designated as indicating sites;

said artwork including contrasting patterns of nomenclature and design functionally designating said indicating sites and also designating positions and functional associations of a plurality of discrete touch sensitive sites coincident with selected intersection points of a predetermined grid;

a switch module mounted behind said overlay;

said module comprising a grid network of perpendicular conductor arrays supported on transparent elastic films separated by a spacing film, the latter film having voids registered centrally with respective said touch sensitive overlay sites;

said coNductors having paired parallel extension segments subject to elastic contact engagement through said voids, said segments being offset relative to crossing intersections of respective conductors and extending across centers of respective said voids, said segment pairs thereby being normally spaced apart by said spacing film and subject to flexed displacement into contact in reaction to touch pressure applied to respective said touch sensitive sites of said overlay;

means for producing light spot indications transmissible through spaces between said conductors in said switch module to said overlay indicating sites; and

modularly constructed printed circuit means mounted for electrical association with said switch module and overlay to provide coupling connections for electrical sensing of said switch module and for selective energization of said light spot producing means.

13. A touch sensitive indicating panel in accordance with claim 12, in which said indicating sites of said overlay membrane comprise a plurality of first indicating sites reserved for transmission of discrete single spot binary indications and a plurality of second indicating sites reserved for transmission of multiple spot indications forming character images of numbers, letters and/or the like;

and in which said modularly constructed printed circuit means comprises;

printed circuits;

means for holding a first plurality of single light spot sources individually aligned with respective said first indicating sites of said overlay and subject to receiving selective electrical excitation to produce respective said single spot indications; and

means for holding a second plurality of discretely spaced multi-spot light generating units, each unit including a group of associatively arrayed light spot sources aligned with a respective second indicating site of said overlay, individual sources of said group being subject to selective excitation to provide said character image indications at respective said second indicating sites.

14. A panel assembly according to claim 13, wherein plural groups of said touch sensitive sites of said overlay are distinguished as groups by said artwork and respective contact segment pairs of said switch module associated with said sites are sensed in corresponding groups;

said assembly further including;

means coupled to said printed circuits of said modularly constructed means for sensing sequential touch contact engagements of paired contact extension segments associated with plural said touch site groups in predetermined position/time combinations; and

means responsive to said combination sensing means for producing complex indication and control effects relative to said second indicating sites of said overlay and said multi-spot light generating units associated therewith.

15. A touch sensitive indicating panel in accordance with claim 12 including means associated with said modularly constructed means for sensing sequenced touch engagements of plural said offset extension segment pairs of said switch module and for providing associated plural touch dependent control and indicating effects relative to said multi-spot generating means.

16. A panel according to claim 15, including bypass means coupled to said sensing and effect providing means for enabling certain said effects to be produced alternately in response to a single control signal from said bypass means and in response to sensing touch operations of a plurality of said offset segment pairs in a predetermined sequence.

17. A touch sensitive indicating panel according to claim 12 wherein said conductors in said arrays of said switch module have redundant connections with said extension segments serving to provide alternate conduction paths useful to sustain continuity for contact sensing when a said segment of a pair is physically broken.

18. A panel according to claim 12 including a transparent stress easing touch transmissive film interposed between the overlay and swiTch module;

said easing film containing voids aligned centrally with edges of said spacing film voids and with corresponding portions of respective said contact segment pairs subject to receiving shearing stresses at said edges.

19. A panel according to claim 13 including a grid frame structure interposed between said printed circuits and switch module;

said structure having discrete compartments respectively sheltering individual said single light spot sources and individual said multi-spot light generating units; and

operating as an assembly alignment structure to provide tolerance positional adjustment of said single sources relative to respective first indicating sites of said overlay.

20. A panel according to claim 19 including a transparent stiffener sheet located between said grid frame and switch module for preventing physical contact between said sheltered light spot sources and switch module and for supplying touch backing support for said switch module.

21. A panel according to claim 13 in which said light spot sources are microminiature light emitting diodes which emit light in a narrow portion of the visible spectrum and said overlay includes a light filtering layer with passband matched closely to the spectrum of said diode emissions, said filtering layer serving to attenuate extraneous background light of broader spectral content.

22. A panel according to claim 12 wherein said switch module includes, as integral extensions of said conductor arrays and support films, a flexible bus assembly capable of extending to and connecting with said modularly constructed means to complete therewith signal conduction paths for touch sensing.

23. In a touch sensitive indicating panel, including a touch transmissive elastic overlay membrane serving as a medium for transmitting touch pressure to elastic switch elements covered by the overlay and for receiving and transferring light indications of predetermined spectral characteristics through spaces between said switch elements, an improved overlay membrane comprising:

a bonded laminate of at least three film layers, including at least one interior layer formed of light transmissive elastic material retained between exterior layers formed of light transmissive elastic material;

said at least one interior layer containing a surface coating of opaque artwork covering a major portion of its surface exclusive of a plurality of discrete single spot and multi-spot indicating sites;

said artwork functionally designating said indicating sites and a plurality of discrete touch sensing sites;

said indicating sites and touch sites being relatively interspersed;

at least one of said exterior layers having a light transmission characteristic confined to a narrow portion of the visible spectrum associated with a spectral emission characteristic of a particular light indication source used with said overlay;

at least one of said exterior layers being gloss treated to reduce specular reflection;

at least one of said exterior layers having selectively located exterior coatings coincident with said single-spot indicating sites productive of rear projection screen spot illumination effects.

24. An improved overlay membrane in accordance with claim 23 in which:

said at least one interior layer is a film of polyvinyl chloride having uniform and predetermined thickness, and said exterior layers are polyester films of uniform and predetermined thickness, and said films are adhesively bonded together to form said laminate.

25. In a touch sensitive indicating panel providing interspersed light indication sites and touch sensing sites, and containing a covering elastic overlay membrane which is useful to transfer touch contact pressure to plural contact elements of an elastic switch module and to transfer viewable light indications from sources positioned behind and between said contact elements, an improved elastic switch module comprising:

first and second arrays of parallel conductors, conductors of said second aRray oriented perpendicular to conductors of said first array;

first and second light transmissive elastic support films retaining respective said conductor arrays in inwardly facing position in said perpendicular orientation; and

a light transmissive spacing film positioned between said support films;

said spacing film having voids associated with but discretely offset from positions of crossover of respective pairs of conductors in said first and second arrays;

said voids centrally aligned with discrete touch sensing sites of said overlay designated and outlined by artwork on said overlay;

individual conductors of said arrays having plural elastic extension segments aligned with centers of respective said spacing film voids;

said extension segments interfacing in pairs to form switch contact elements of said switch module;

the paired segments of each contact element being disposed in parallel to each other for enhanced contact engagement.

26. In a touch sensitive indicating panel an improved elastic switch module comprising:

first and second conductor arrays separated by a spacing film having voids centered at touch sensing positions intercepted by discrete pairs of relatively perpendicular conductors in said first and second arrays; and

a stress reducing film covering said module;

said stress reducing film having voids centrally aligned with edges of said spacing film voids at positions of shearing stress contact with said conductors.

27. In a touch sensitive indicating panel providing multiple interspersed touch sensing sites and light spot indicating sites at the surface of a single flat elastic overlay membrane backed by a grid configuration of modularly associated elastic touch contact elements the improvement comprising:

means for conditioning said contact elements with electrical scanning pulses applied to said elements in a predetermined scanning sequence;

means common to all of said contact elements for detecting touch operation of any of said conditioned elements;

means coupled to said common detecting means for producing a sense sampling pulse of a predetermined short duration in response to a detected touch operation of comparatively long duration;

plural conditionally operable positionally oriented sensing circuits coupled to individual said contact elements for sensing and providing indications of touch operations thereof;

means for applying said sampling pulses to said positionally oriented sensing circuits; and

means selectively responsive to operations of certain less than all of said positionally oriented sensing circuits in response to said scanning pulses to condition said sampling pulse applying means to apply said scanning pulses alternately to all of said sensing circuits and to only said certain sensing circuits.

28. A panel according to claim 27 wherein said certain sensing circuits are associated with at least one contact element designated for control of delivery of panel power to touch sensing and indication elements and at least one other contact element designated for control of enablement and disablement of panel touch sensitivity only.

29. In a panel according to claim 27:

scan control means coupled to said common detecting means conditionable to disable said scan conditioning means and halt said scan sequence upon initial detection of any touch operation thereby establishing a statically sensible electrical condition in the touch operated contact element, said control means reactivating said scan sequence upon release of the touched contact.

30. In a panel according to claim 29:

means coupled to said scan control means conditionable to provide a perceptible feedback indication for the duration of touch operation of each touched contact element.

31. A panel according to claim 30 wherein said feedback indication is a distinct audible tone.

32. In a touch sensitive indicating panel having interspersed light spot indicating sites and touch sensing sites located at thE surface of an integral elastic overlay membrane and a multi-channel interface for connection to host apparatus the improvement comprising:

means responsive to momentary touch operations of individual said touch sensitive sites to provide staticized electrical signal indications representative thereof;

means responsive to predetermined combinations of momentary touch operations of particular said touch sensitive sites sensed in combination with associated said representative staticized signal indications derived from previously applied touch operations to provide a control signal for each said combination of particular significance in respect to said combination; and

means responsive to said control signals to produce light spot indications at various said indicating sites and control and input effects relative to selected channels of said host interface.

33. In a panel according to claim 32:

bypass means coupled to said control signal responsive means for supplying control signals independently of said combination responsive means, said bypass means linked with said host apparatus.

34. In a touch sensitive indicating panel in combination:

an elastic overlay membrane formed of transparent material and having a plurality of interspersed light spot indicating sites and touch sensing sites on a surface thereof;

said sites distinguished by opaque artwork coatings;

said overlay surface gloss treated to reduce specular reflection;

said indicating sites comprising first and second sites of distinct outline;

said first sites reserved for single spot on-off indication and said second sites reserved for multi-spot character image indication;

said overlay material including a narrow band filtering characteristic for selective transmission of light in a portion of the visible spectrum;

said first sites having rear projection screen coatings;

a printed circuit module mounted in parallel with said overlay;

a plurality of light spot emissive devices mounted on said module and facing said overlay;

single said devices aligned with respective said first indicating sites and groups of multiple said devices aligned with said second sites;

said devices being excitable to emit light energy predominantly confined to said portion of said visible spectrum;

a supportive grid structure between said printed circuit module and overlay having openings for sheltering said light emissive devices;

an elastic switch module interposed between said overlay and supportive grid structure;

said switch module comprising upper and lower transparent elastic support films containing respective relatively perpendicular arrays of parallel conductors positioned so as not to interfere with passage of light from said emissive devices to said overlay;

paired perpendicular conductors of said arrays having elastic extension segments paired as contacts at crossing positions of the respective conductors;

said segments of each pair being offset from respective crossing positions of respective conductors and extending parallel to each other;

said segments being aligned with said overlay touch sensing sites;

said arrays being separated by a transparent spacer film having multiple voids centrally aligned with respective said paired offset segments;

said switch module being supported by a transparent stiffener sheet interposed between the grid structure and switch module;

stresses on said switch module being eased by a flexible stress easing film interposed between the overlay and the switch module;

said printed circuit module backed by a foam backing sheet and an electrical noise shield;

said switch module having an integral flexible bus extension connecting with the printed circuit module for conveying conditioning signals to the switch module and touch sensing signals from operated contacts of the switch module.

35. The combination of claim 34 together with first circuit means coupled to said switch module via said printed circuit module for providing inpUt conditioning signals to one segment of each of said paired contact segments in a predetermined cyclic sequence;

second circuit means coupled to said switch module for detecting transferral of said conditioning signal to the other segment of any said contact pair when said any contact pair is operated to closed position by touch pressure transferred through said overlay;

third circuit means coupled to said switch module and second means for sensing the particular contact pair transferring said conditioning signal;

fourth circuit means coupled to particular outputs of said third circuit means for conditionally disabling and enabling a part of said third circuit means whereby only contact pairs of a particular subset of all pairs can be sensed by said third circuit means is disabled condition and all pairs can be sensed in enabled condition;

fifth circuit means coupled to said third circuit means for producing control and indication effects relative to said emissive devices; and

sixth circuit means coupled to said fifth circuit means for providing control inputs to said fifth means bypassing said fourth means, and thereby providing alternate control of said effects.

36. The combination of touch sensitive indicating panel elements in accordance with claim 35 wherein said second circuit means includes antibounce circuit means providing pre and post protection against spurious detection of said conditioning signal transferral.