US3811025A - Touch panel switch assembly - Google Patents

Touch panel switch assembly Download PDF

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Publication number
US3811025A
US3811025A US36128473A US3811025A US 3811025 A US3811025 A US 3811025A US 36128473 A US36128473 A US 36128473A US 3811025 A US3811025 A US 3811025A
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Prior art keywords
switch assembly
button
panel
shroud
control panel
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Expired - Lifetime
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R Bach
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Lockheed Electronics Co Inc
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Lockheed Electronics Co Inc
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    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/70Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard
    • H01H13/83Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard characterised by legends, e.g. Braille, liquid crystal displays, light emitting or optical elements

Abstract

A multi-layer touch panel switch assembly for particular application as a control panel for computers. The front panel is a smooth surface with no exposed switch handles. An operator depresses a selected area causing metallic surfaces to momentarily make contact, lighting a LED indicator located behind transparent areas in the panel. A silicone button having the desired flexibility and having excellent memory characteristics is used to transfer the pressure to close the electrical contacts. The front panel and switches may be inexpensively manufactured using printed circuit techniques and flow soldering operations.

Description

United States Patent [191 Bach TOUCH PANEL SWITCH ASSEMBLY [75] lnventor: Richard R. Bach, Downey, Calif.

[73] Assignee: Lockheed Electronics Company,

I nc., Plainfield, NJ.

[22] Filed: May 17, 1973 [21] Appl. No.: 361,284

[52] US. Cl.,.... ..200/3l7, 200/5 A, 200/159 1} [51] Int. Cl. H01h 3/12, HOlh 9/16 [58] Field of Search 200/159 R, 159 B, 5 A,

200/167 R, 167 A; 340/365 A [56] References Cited UNITED STATES PATENTS 3,766,350 10/1973 Van Dyk et a1. 200/167 A 3,509,296 4/1970 Harshman et al....; 200/159 R 3,732,389 5/1973 Kaelin et a1 340/365 A 3,627,927 12/1971 Schmitz 200/l59 B X 3,591,749 7/1971 Comstock 200/167 R 3,617,660 11/1971 Krakinowski 200/159 B X [451 May 14,1974

3,691,985 9/1972 Otterlei 200/167 R X Primary Examiner-Robert K. Schaefer Assistant Examiner--William J. Smith Attorney, Agent, or Firm-Billy G. Corber; Albert K.

Geer

57 ABSTRACT A multi-layer touch panel switch assembly for particular application as a control panel for computers. The front panel is a smooth surface with no exposed switch handles. An operator depresses a selected area causing metallic surfaces to momentarily make contact, lighting a LED indicator located behind transparent areas in the panel. A silicone button having the desired flexibility and having excellent memory characteristics is used to transfer the pressure to close the electrical contacts. The front panel and switches may be inexpensively manufactured using printed circuit techniques and flow soldering operations.

4 Claims, 2 Drawing Figures 1 TOUCH PANEL SWITCH ASSEMBLY THE PRIOR ART Control panel low profile keyboards, in general, use either true contacts or an elastomeric material which under compression reduces its resistance from ohms to 10 ohms. In an article by Jerome Lyman entitled Keyswitches and Keyboards", EEE, for November 1970, pages 64 through 73, an excellent summary of available switches is presented.

The biggest drawback to the known low profile touch switches is the lack of inherent feedback to a human operator who does not know when he has pushed enough to close the switch. One solution is to produce an audible click each time a switch is closed; another is to mount a key on the top of each low profile touch switch. The less costly clicking is preferred over the key. Further, it is desirable to provide a switch having a relatively long life on the order of 10, or more, mechanical and electrical cycles. It is also desirable to provide a control panel switch, or the like, which is sealed from the elements as well as the operator and is easy to. operate.

In summary, the present invention overcomes many of the shortcomings of the prior art by using a continuous non-perforated, flexible front panel on which the proper markings, characters, etc., are applied. Behind each marking, character, etc. is an elastomeric button which is sensitive to touch and yet has a high memory characteristic which returns it.to its original position. Pressure on the button closes contacts to a grid pattern and a light emitting diode (LED) is energized to indicate the particular button which has been depressed.

Accordingly, it is a primary object of the invention to provide a touch panelassembly which is sensitive to the operators touch and has high restoration characteristics. 1

Another object of the invention is to provide a low cost, highly reliable push button indicator switch.

A further object of the invention is tov provide a sealed, low profile switch which is easy to operate at low cost.

The foregoing and other objects will become more apparent from the following description when taken with the accompanyingdrawings', in which:

FIG I is an exploded trimetric view of a computer control panel in accordance with the invention; and

FIG. 2 is a cross-sectional view of two switches of a control panel such as shown in FIG. 1.

Now, referring tothe drawings, the exploded FIG. 1 shows the control panel assembly consisting of a printed circuit (PC) board 1, a shroud 3 and a front decorative panel "5. A resilient button 6 is mounted in the shroud 3, and strips 7 and 8 are mounted between the shroud 3 and printed circuit (PC) board 1, all to be explained hereinafter. It will be noted that the button 6 is retained in the aperture 3A of shroud 3 and the strips 7 and 8 are between theshroud 3 and the PC board 1, aswill be more fully explained in connection with FIG. 2. The PC board 1 contains a grid pattern 1A, which may be arranged according to a standard format, the grid and interconnections (not shown) to the edge of the PC board being formedby well known printing techniques, or theequivalent. ThePC board is positionedby means of spacers 9 fromthe back cover 10.

In FIG. 2, the back cover 10 and spacer have been omitted for clarity, only an enlarged cross-sectional view being shown. The strips 7 and 8 are positioned between the PC board 1 and the shroud 3 on alignment pins 3C at either end of the shroud 3, one being shown in FIG. 2. The strip 7 is made of an insulating plastic backing such as mylar or polyester, and has bonded thereto areas of a conductive material 7A, such as gold or the like, the conductive areas being positioned on the strip 7 to overlay the grid pattern 1A on the PC board. The strip 8 lies between the strip 7 and the PC board, and includes apertures 8A which are arranged to overlay the conductive area 7A. When the strips 7 and 8 are positioned between the shroud 3 and PC board 1, the aperture 3A in the shroud, the switch button 6, the conductive area 7A, the aperture 8A and the grid pattern 1A are all in alignment, as indicated in FIG. 2, so that pressure on the switch button 6 displaces the conductive' area 7A into engagement with the grid pattern 1A.

Details of the switch button 6 are shown in FIG. 2, a general perspective view being seen in FIG. 1. The body of the button is preferably cylindrical in shape, although it is readily apparent that the cylindrical shape is selected for convenience, and not because of limitation. In the body 6 is an annular depression 6A, which will be referred to herein as an annular channel or groove 6A. It will be noted that the channel is approximately two-thirds of the height of the cylinder,'leaving about one-third material in the ,flexible areaid), and the radius (r) of the outer annulus is about one-third that of theiradius (R) of the switch button. Also, while the button material is not critical, it has been found that elastomers, such as silicone rubber, are highly satisfac-- tory.

A plurality of switch assemblies, as illustrated in FIGS. 1 and 2, are arranged in a conventional format. The numerals (0 15), for register, address and data, and characters or legends, such as reset, write, read, etc. are conveniently arranged in a plurality of rows, e.g. 4, and columns, e.g. 19. The numerals, legends, etc, are applied to the front decorative panel in any convenient manner.

However, on a preferred embodiment, the decorative panel 5 is made of a laminate of mylar and polyvinyl chloride (PVC), such as a l mil mylar film bonded to about a 14 mil base of polyvinyl chloride vinyl acetate, with the mylar film on the outer face of the panel. The back side of the panel is covered with an opaque coating, except for transparent areas for the numerals, characters, etc. Suitably colored strips may be applied to the back side of the panel, so that certain numerals may be illuminated in one color and others in different colors. For example, front panel functions (inputs) such as write, read, load, etc. may be in one color, while machine states, such as busy, idle", done, etc. are preferably in a different color. Above each numeral, character or legend is a transparent area 12. Behind the transparent area 12 is a light emitting diode 11 (LED), or equivalent, which is mounted on the PC 1 adjacent to the grid 1A (connections to the grid are omitted as being obvious), so that the LED is illuminated when the switch is energized, thereby providing a visual feedback to the operator or programmer. As is apparent from FIG. 1, the LED projects into the aperture 33 in the shroud 3. The material of the shroud is preferably an opaque phenolic sheet, such as to have very low or nil light transmitting qualities, to thereby concentrate the light of the LED on the transparent area 12.

The switch assembly as shown in FIGS. 1 and 2 and described above should be assembled so that when the operator or programmer presses an area designated by a number, character, etc., only the LED above that area will be illuminated. For example, in FIG. 2 the center-to-center distance between buttons 6 might be around inch, which results in a spacing between holes 3A in shroud 3 of about Vs inch, thereby preventing pressure transfer to the next button(s).

Further, the dimensions and tolerances of the switch assembly as viewed in FIG. 2 are not critical, although it is regarded as important that certain conditions be met. The volume of the button 6 above the annular channel 6A should be such that the center portion of the button will be deflected under moderate pressure to force the conductive area 7A of strip 7 into electrical contact with the grid 1A, and still have adequate restoration characteristics for a long operation life. As an example, for less resilient materials the thickness d would be less.

What is claimed is: 1. A pressure sensitive switch assembly in combination with a control panel comprising:

a. a printed circuit having a discontinuous grid pattern thereon; b. an apertured insulator having apertures positioned over said grid;

c. an insulator having conductive areas on one side thereof, said areas being positioned over the aforementioned apertures;

d. an apertured shroud having the apertures positioned over said conductive areas;

e. flexible buttons located in the shroud apertures and in proximity with the other side of said second insulator contiguous to said conductive areas; and

3. A pressure switch assembly as defined in claim 2, and wherein the thickness of the button material remaining at the bottom of the channel is less than onethird the thickness of the material adjacent the channel.

4. A pressure actuated switch assembly as defined by claim 1, and wherein the control panel contains indicia and legends overlying said buttons to indicate to an operator computer inputs, functions and the like.

Claims (4)

1. A pressure sensitive switch assembly in combination with a control panel comprising: a. a printed circuit having a discontinuous grid pattern thereon; b. an apertured insulator having apertures positioned over said grid; c. an insulator having conductive areas on one side thereof, said areas being positioned over the aforementioned apertures; d. an apertured shroud having the apertures positioned over said conductive areas; e. flexible buttons located in the shroud apertures and in proximity with the other side of said second insulator contiguous to said conductive areas; and f. light emitting means mounted on said printed circuit and located adjacent said shroud aperture whereby depressing the control panel also depresses said button and causes a connection to be made across said grid, thereby energizing said light emitting means.
2. A pressure switch assembly as defined in claim 1, wherein the flexible button is made of an elastomer and having a channel therein spaced from its central axis.
3. A pressure switch assembly as defined in claim 2, and wherein the thickness of the button material remaining at the bottom of the channel is less than one-third the thickness of the material adjacent the channel.
4. A pressure actuated switch assembly as defined by claim 1, and wherein the control panel contains indicia and legends overlying said buttons to indicate to an operator computer inputs, functions and the like.
US3811025A 1973-05-17 1973-05-17 Touch panel switch assembly Expired - Lifetime US3811025A (en)

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Cited By (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3916135A (en) * 1974-07-03 1975-10-28 Hewlett Packard Co Keyboard type switch with rocker type key actuator
US3917917A (en) * 1973-08-23 1975-11-04 Alps Electric Co Ltd Keyboard pushbutton switch assembly having multilayer contact and circuit structure
US3969721A (en) * 1975-11-05 1976-07-13 Northern Electric Company Limited Light emitting diode indicator assembly for a multiple pushbutton array
US3996428A (en) * 1975-03-17 1976-12-07 Litronix, Inc. Pushbutton keyboard assembly with over center diaphragm contact
US4005296A (en) * 1974-10-29 1977-01-25 Medtronic, Inc. Disc switch
US4022993A (en) * 1975-06-09 1977-05-10 Litton Systems, Inc. Switch assembly having electrically illuminated character display devices between transparent actuators and switch arrays
US4035593A (en) * 1975-10-09 1977-07-12 Northern Engraving Company, Inc. Flexible pressure sensitive switch actuator module adaptable to a keyboard surface having fixed contact array
US4060703A (en) * 1976-11-10 1977-11-29 Everett Jr Seth Leroy Keyboard switch assembly with tactile feedback having illuminated laminated layers including opaque or transparent conductive layer
US4077036A (en) * 1976-08-30 1978-02-28 Emik A. Avakian Data entry devices
US4163138A (en) * 1978-03-17 1979-07-31 Bowmar Instrument Corporation Flush lighted flat keyboard assembly
FR2426322A1 (en) * 1978-05-18 1979-12-14 Siemens Ag Switch a push button
US4179594A (en) * 1978-09-12 1979-12-18 Westinghouse Electric Corp. Illuminated pushbutton assembly
US4194099A (en) * 1977-10-25 1980-03-18 W. H. Brady Co. Control panel overlay
JPS55145820U (en) * 1979-04-04 1980-10-20
US4234872A (en) * 1978-03-08 1980-11-18 Lgz Landis & Gyr Zug Ag Circuit arrangement for a keyboard
US4262182A (en) * 1980-01-11 1981-04-14 General Electric Company Fully illuminated backlit membrane touch switch
FR2472138A2 (en) * 1979-12-21 1981-06-26 Jaeger Lighting device keyboard has keys
JPS5710089U (en) * 1980-06-13 1982-01-19
US4317011A (en) * 1980-01-21 1982-02-23 Chicago Decal Company Membrane touch switch
US4347416A (en) * 1980-05-12 1982-08-31 Ralph Ogden Membrane switch control panel arrangement and label assembly for labeling same
JPS582930U (en) * 1981-06-30 1983-01-10
US4376879A (en) * 1980-10-28 1983-03-15 Japan Aviation Electronics Industry Limited Button-less push switch boards
WO1983000946A1 (en) * 1981-09-10 1983-03-17 Gafner, Gottfried Pannel with light keys
US4449024A (en) * 1983-05-03 1984-05-15 Kb Denver, Inc. Backlighted illuminated keyboard
US4478666A (en) * 1981-11-02 1984-10-23 Ralph Ogden Membrane switch control panel arrangement and label assembly for labeling same
US4531034A (en) * 1983-03-24 1985-07-23 Nitsuko Limited Key switch devices with indicator lamp means
JPS61198318A (en) * 1985-09-06 1986-09-02 Canon Inc Operation input device
US4894493A (en) * 1988-11-04 1990-01-16 General Electric Company Membrane touch control panel assembly for an appliance with a glass control panel
US5698826A (en) * 1995-02-01 1997-12-16 Maytag Corporation Selective back lighting of appliance control panel
US5938772A (en) * 1997-06-11 1999-08-17 Compaq Computer Corporation Responsive backlit hardwire button array providing illumination and user feedback in a computer
US6002779A (en) * 1997-10-02 1999-12-14 Johnston; William R. Automated voice message system and method
US6076133A (en) * 1997-04-30 2000-06-13 Compaq Computer Corporation Computer interface with hardwire button array
US6353533B1 (en) 1997-06-13 2002-03-05 Compaq Information Technologies Group, L.P. Ergonomic controls for a personal computer CPU
US20080096616A1 (en) * 2006-10-18 2008-04-24 Lg Electronics Inc. Mobile terminal
US20100096245A1 (en) * 2007-11-08 2010-04-22 Grzan John T Linear pressure switch apparatus and method

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3509296A (en) * 1967-10-23 1970-04-28 Ncr Co Resilient variable-conductivity circuit controlling means
US3591749A (en) * 1969-05-12 1971-07-06 Singer Co Printed circuit keyboard
US3617660A (en) * 1970-01-23 1971-11-02 Ibm Keyboard actuating mechanism for diaphragm electric switch contact array
US3627927A (en) * 1969-11-24 1971-12-14 Sanders Associates Inc Monolithic keyboard and method for making same
US3691985A (en) * 1971-02-08 1972-09-19 Jon L Otterlei Spring biasing means for a self-illuminating pushbutton
US3732389A (en) * 1972-02-14 1973-05-08 Litton Systems Inc Touch entry switch array
US3766350A (en) * 1972-03-15 1973-10-16 Northern Electric Co Mounting of a light emitting device on a circuit

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3509296A (en) * 1967-10-23 1970-04-28 Ncr Co Resilient variable-conductivity circuit controlling means
US3591749A (en) * 1969-05-12 1971-07-06 Singer Co Printed circuit keyboard
US3627927A (en) * 1969-11-24 1971-12-14 Sanders Associates Inc Monolithic keyboard and method for making same
US3617660A (en) * 1970-01-23 1971-11-02 Ibm Keyboard actuating mechanism for diaphragm electric switch contact array
US3691985A (en) * 1971-02-08 1972-09-19 Jon L Otterlei Spring biasing means for a self-illuminating pushbutton
US3732389A (en) * 1972-02-14 1973-05-08 Litton Systems Inc Touch entry switch array
US3766350A (en) * 1972-03-15 1973-10-16 Northern Electric Co Mounting of a light emitting device on a circuit

Cited By (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3917917A (en) * 1973-08-23 1975-11-04 Alps Electric Co Ltd Keyboard pushbutton switch assembly having multilayer contact and circuit structure
US3916135A (en) * 1974-07-03 1975-10-28 Hewlett Packard Co Keyboard type switch with rocker type key actuator
US4005296A (en) * 1974-10-29 1977-01-25 Medtronic, Inc. Disc switch
US3996428A (en) * 1975-03-17 1976-12-07 Litronix, Inc. Pushbutton keyboard assembly with over center diaphragm contact
US4022993A (en) * 1975-06-09 1977-05-10 Litton Systems, Inc. Switch assembly having electrically illuminated character display devices between transparent actuators and switch arrays
US4035593A (en) * 1975-10-09 1977-07-12 Northern Engraving Company, Inc. Flexible pressure sensitive switch actuator module adaptable to a keyboard surface having fixed contact array
US3969721A (en) * 1975-11-05 1976-07-13 Northern Electric Company Limited Light emitting diode indicator assembly for a multiple pushbutton array
FR2331139A1 (en) * 1975-11-05 1977-06-03 Northern Telecom Ltd indicator assembly has photo-emitting diodes for a device has multiple buttons
US4077036A (en) * 1976-08-30 1978-02-28 Emik A. Avakian Data entry devices
US4060703A (en) * 1976-11-10 1977-11-29 Everett Jr Seth Leroy Keyboard switch assembly with tactile feedback having illuminated laminated layers including opaque or transparent conductive layer
US4194099A (en) * 1977-10-25 1980-03-18 W. H. Brady Co. Control panel overlay
US4234872A (en) * 1978-03-08 1980-11-18 Lgz Landis & Gyr Zug Ag Circuit arrangement for a keyboard
US4163138A (en) * 1978-03-17 1979-07-31 Bowmar Instrument Corporation Flush lighted flat keyboard assembly
FR2426322A1 (en) * 1978-05-18 1979-12-14 Siemens Ag Switch a push button
US4225766A (en) * 1978-05-18 1980-09-30 Siemens Aktiengesellschaft Touch contact
US4179594A (en) * 1978-09-12 1979-12-18 Westinghouse Electric Corp. Illuminated pushbutton assembly
JPS55145820U (en) * 1979-04-04 1980-10-20
FR2472138A2 (en) * 1979-12-21 1981-06-26 Jaeger Lighting device keyboard has keys
US4262182A (en) * 1980-01-11 1981-04-14 General Electric Company Fully illuminated backlit membrane touch switch
US4317011A (en) * 1980-01-21 1982-02-23 Chicago Decal Company Membrane touch switch
US4347416A (en) * 1980-05-12 1982-08-31 Ralph Ogden Membrane switch control panel arrangement and label assembly for labeling same
JPS5710089U (en) * 1980-06-13 1982-01-19
JPS647437Y2 (en) * 1980-06-13 1989-02-28
US4376879A (en) * 1980-10-28 1983-03-15 Japan Aviation Electronics Industry Limited Button-less push switch boards
JPS582930U (en) * 1981-06-30 1983-01-10
WO1983000946A1 (en) * 1981-09-10 1983-03-17 Gafner, Gottfried Pannel with light keys
US4478666A (en) * 1981-11-02 1984-10-23 Ralph Ogden Membrane switch control panel arrangement and label assembly for labeling same
US4531034A (en) * 1983-03-24 1985-07-23 Nitsuko Limited Key switch devices with indicator lamp means
US4449024A (en) * 1983-05-03 1984-05-15 Kb Denver, Inc. Backlighted illuminated keyboard
JPS61198318A (en) * 1985-09-06 1986-09-02 Canon Inc Operation input device
US4894493A (en) * 1988-11-04 1990-01-16 General Electric Company Membrane touch control panel assembly for an appliance with a glass control panel
US5698826A (en) * 1995-02-01 1997-12-16 Maytag Corporation Selective back lighting of appliance control panel
US6076133A (en) * 1997-04-30 2000-06-13 Compaq Computer Corporation Computer interface with hardwire button array
US5938772A (en) * 1997-06-11 1999-08-17 Compaq Computer Corporation Responsive backlit hardwire button array providing illumination and user feedback in a computer
US6353533B1 (en) 1997-06-13 2002-03-05 Compaq Information Technologies Group, L.P. Ergonomic controls for a personal computer CPU
US6002779A (en) * 1997-10-02 1999-12-14 Johnston; William R. Automated voice message system and method
US20080096616A1 (en) * 2006-10-18 2008-04-24 Lg Electronics Inc. Mobile terminal
DE102007003268A1 (en) * 2006-10-18 2008-04-24 Lg Electronics Inc. mobile device
US7826806B2 (en) 2006-10-18 2010-11-02 Lg Electronics Inc. Mobile terminal
US20100096245A1 (en) * 2007-11-08 2010-04-22 Grzan John T Linear pressure switch apparatus and method
US8026454B2 (en) * 2007-11-08 2011-09-27 Grzan John T Linear pressure switch apparatus and method

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