US 3641299 A
A switch having a transparent area and suitable for placing over a video display without obscuring the information displayed beneath the switch. The switch comprises an elastically bendable conducting strip which, when a top transparent member of the switch is pushed, is forced into contact with a conducting area on the top transparent member. The natural elasticity in the bendable strip serves to break the contact between the conducting area and the bendable strip when the switch is released.
Claims available in
Description (OCR text may contain errors)
United States Patent Mayer  DISPLAY FACEPLATE SWITCH  Inventor: William N. Mayer, White Bear Lake,
 Assignee: Control Data Corporation, Minneapolis,
 Filed: Feb. 10, 1971  Appl. No.: 114,283
 U.S.Cl .200/167 R, 200/166 J, ZOO/186R  Int. Cl. ..H01h 9/16  Field of Search ..200/167 R, 167 A, 86 R, 159 B,
 References Cited UNITED STATES PATENTS Roby ..200/86 R Feb. 8, 1972 "3,591,749 7/1971 Comstock ..200/l67R Primary Examiner-H. 0. Jones Attorney-Joseph A. Genovese, Edward Schwarz and Paul L.
Sjoquist  ABSTRACT A switch having a transparent area and suitable for placing over a video display without obscuring the information displayed beneath the switch. The switch comprises an elastically bendable conducting strip which, when a top transparent member of the switch is pushed, is forced into contact with a conducting area on the top transparent member. The natural elasticity in the bendable strip serves to break the contact between the conducting area and the bendable strip when the switch is released.
13 Claims, 2 Drawing Figures PATENTEDFEB 81972 3.641.299
SHEET 1 OF 2 I NVENTOR.
BY l/l /'///'am A/ Mayer ATTORNEY PATENTED FEB 8 I972 SHEET 2 OF 2 I NVENTOR. W/'///am /V. Mayer ATTORNE- DISPLAY FACEPLATE SWITCH BACKGROUND OF THE INVENTION 1. Field of the Invention In forming an interface between an information display device and the human for which the information is being displayed, it is often necessary for the human to select which of several messages should be elaborated or expanded upon. As an example, consider the computerization of the Patent Office Manual of Classification for the purpose of rapidly selecting the appropriate classification for a newly received patent application. A first group of messages would be chosen, each message naming a single class. The most appropriate class from this group would be selected. This would cause the computer to display a group of subclasses more narrowly defining areas within the selected class. This selection and display of new groups would continue until a narrow enough selection had been made to precisely specify the class and subclass to which the patent application would belong. Other obvious applications for such interactive display operations are. present in computer-aided medical diagnosis and legal research.
The switch which is the subject of this invention is designed to fit over a particular message area of a display. A plurality of switches are placed on the face of the display, the area beneath one switch being used for displaying one message. Selection of the most appropriate message is made by depressing the switch placed over it, generating a signal causing the computer to display a group of messages associated with the selected one.
2. Description of the Prior Art A variety of methods have been utilized in attempting to make such selections. The simplest of course would be a series of pushbuttons placed along the periphery of the display device, one in close proximity to each message display area. While inexpensive, this type of message selecting apparatus is undesirable because actual usage has shown it to cause many operator errors because of its poor human engineering. Another design uses a light pen and a screen having light sensing capability. A frequently used method operates with phase variations in an RF field caused'by touching a transparent conductive patch above the message display area and provides an accurate and reliable means for performing the selection operation. Another design employs collimnated light beams and photo cells disposed in a rectangular matrix arrangement. Interruption of an X- and a Y-beam defines the message display area selected. Other similar apparatus is described in US. Pat. No. 3,292,489, Johnson et al., and Digital Computer Newsletter, p. 9, Jan. 1967. However, most of these designs are quite technically complex, causing unnecessary expense or unreliability. Accordingly, one object of this invention is to provide an inexpensive means for indicating electrically an operators selection of a particular message display area.
Another object is to provide an easily replaceable selection indicator.
A further object of the invention is to provide for easy changing of the dimensions of the message display area covered by the switch.
A fourth object is to decrease operators errors in message selection.
Still another object is to provide a switch having a low-activating force which remains relatively constant over the entire area exposed to manipulation by the operator. Other objects of the invention will become apparent upon understanding the succeeding description of the invention.
SUMMARY OF THE INVENTION The actuating member of the switch (corresponding to the handle of a more conventional switch) comprises a transparent plate or strip of a material such as glass having a conductive area functioning as one contact in the switch. This conductive area may be a narrow metal strip attached by a suitable adhesive to the transparent plate. Thus at least one transparent viewing area is created in a portion of the actuating member. The second contact in the switch is an elastically bendable conducting strip, preferably having the dimensions of the conductive area of the actuating member. This bendable conducting strip has a display side, and a viewer side opposite the display side. The bendable conducting strip is held in adjacent and spaced facing relationship to the conductive area of the actuating member by small insulating standoffs attached in spaced relationship to the viewer side of the bendable conducting strip. The standoffs are attached to the actuating member. and bendable strip with a suitable adhesive or other convenient means. Thus, the switch is completely transparent except for a small area where the conductors obscure vision. Dimensions of the switch and conductors must be selected so as to cause the transparent viewing area (or areas) to correspond to the dimensions of the display area.
A plurality of attachment standoffs, each thicker than the insulating standoffs, are affixed to the display side of the bendable conducting strip. Each of the attachment standoffs is attached approximately midway between the attachment points of the insulating standoffs. As with the insulating standoffs, a suitable adhesive may be used for this attachment. The switch is attached to the display surface by its attachment standoffs, adhesive being used for this also.
In operation, the switch may be depressed at any point on the actuating member by the operator, causing the bendable conducting strip to contact a portion of the conductive area on the actuating member, thereby closing the switch and completing an electrical circuit. When the actuating member is released by the operator, the bendable conducting strip returns to its original shape and the electrical contact is broken.
BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, actuating member 10 comprises thin, fiat plate or strip 15 having an optically transparent area in one axis and carrying conductive area or strip 14. Transparent strip 15 may be made of a variety of materials, such as glass or clear plastic. Glass, however, is preferable in most cases because of its resistance to scratching. For a rectangular viewing area A in. high by 6 in. long, transparent strip 15 of actuating member 10 may have a rectangular transparent area in. high X 6% in. long and be 5/64 in. thick. Conductive area 14 is shown as a U-shaped metal strip having external dimensions equal to those of the transparent area of strip 15 and attached to strip 15 such that each arm is disposed on the outer edge of one face of the transparent area and along its long dimension. Each arm may be one-sixteenth in. wide, and slightly shorter than the length of transparent strip 15. Such a U-shaped strip, if used for conductive area 14, may be attached to transparent strip 15 by any suitable adhesive, such as epoxy. Alternatively, conductive area 14 may comprise a similar U-shaped metal strip having slightly longer arms of length at least equal to the length of transparent strip 15 so that the portion of the U-shaped strip connecting its two arms does not touch transparent strip 15. In either case, the area of actuating member 10 between the two arms of the U-shaped strip constitutes a transparent area through which a message displayed beneath the switch may be seen. Another possible embodiment comprises a single conductive strip running across the entire long dimension of one face of the transparent area on some line between the edges. This strip is preferably very narrow so as to interfere with viewing of information displayed below the switch as little as possible. This configuration is ideal when several lines of alphanumeric data are being displayed, for the strip may occupy the unused area between two lines. To keep activating member from rocking slightly on this conducting strip, this strip may have perpendicular arms of length equal to the width of transparent strip 14 at each end, thus forming an T-shaped conductive area.
Attached at spaced intervals to actuating member 10 are a plurality of insulating standoffs 13. Attachment to conductive area 14 is preferred, but not necessary. Insulating standoffs 13 may be made of rubber or plastic and attached to actuating member 10 with an adhesive. They may have dimensions onesixteenth in. wide by one-eighth in. long and be 0.003 in. thick. Distance between successive attachment points may be from 1 to 2 in. Attached to insulating standoffs 13 is an elastically bendable conducting strip 12 having viewer and display sides, respectively facing toward and away from actuating member 10. Hard beryllium copper alloy 0.01 in. thick is a suitable material from which to make bendable conducting strip 12 if its arms are approximately one-sixteenth in. wide. Such dimensions and material provide a desirable l to 3 oz. operating force. If width is substantially changed or a different material is used, a thickness change may be necessary. The physical laws governing elastic bending of beams are well known. Those skilled in the art can easily calculate a different thickness for bendable conducting strip 12. The 1 to 3 oz. operating force range is very wide, so empirical testing may yield sufficiently accurate results also. Bendable conducting strip 12 preferably has length and height dimensions and shape substantially those of conductive area 14. When attached to insulating standoffs l3, bendable conducting strip 12 has its viewer side disposed in spaced and adjacent facing relationship to conductive area 14. If preferred, bendable conducting strip 12 may be replaced by two elastically bendable conducting strips, each having the dimensions of one arm of the U-shaped conducting strip described. For increased life and reliability and decreased contact resistance, bendable conducting strip 12 and conductive area 14 may be plated with gold at least in the areas between adjacent insulating standoffs l3 and at the ends of the conductive strips, i.e., in the contact areas.
A plurality of attachment standoffs 11 are attached to the display side of bendable conductive strip 12 midway between the attachment points of successive insulating standoffs 13, and at the ends of the arms of bendable conducting strip 12. Standoffs 11 may be attached to bendable conducting strip 12 with a suitable adhesive. Standoffs 11 should be somewhat thicker than standoffs 13, but may have similar lengths and heights. If insulating standoffs 13 are 0.003 in. thick, 0.006 in. is an acceptable thickness for standoffs 11. This greater thickness is necessary to prevent interference in operation by display surface 23.
The entire switch assembly is attached to display surface 23 by the plurality of attachment standoffs 11. A suitable adhesive may be used to effect this attachment also. Tabs 17 and 18 provide a convenient attachment point for conductors 19. Tabs 17 and 18 may be integral with bendable conducting strip 12 and conductive area 14, or may be attached in some convenient manner. The conductors 19 are switch leads adapted to be connected operatively with the source of signals (e.g., a computer system) producing the information shown on the face 23 of the display.
FIG. 2 shows the switch closed with current able to flow through it. Pushing at any point on actuating member 10 causing bendable strip 12 to flex such that conductive area 14 touches bendable conducting strip 12 at or near the point of attachment of at least one standoff 11. When actuating member 10 is released, bendable member 12 straightens elastically breaking the contact.
In use, a plurality of these switches are attached to the face of a display. In general, it is most convenient to form two rows or two columns of the switches so as to allow conductors 19 to be easily led from them. The size of each switch may be different from that of any other switch in the display. As information appears beneath each switch, it is immediately visible to the operator whose hand is naturally lead to the switch associated with the information.
Many variants on the embodiments described are possible. Conductive area 14 may comprise a transparent conductive coating covering the entire area of actuating member 10 facing bendable strip 14. In such a case, this coating would replace the described U-shaped conductive strip. If the display area is very large, it may be preferable to cover only a portion of the message area. Other variants will also suggest themselves to those skilled in the art.
Having described the basic invention and several variations of it, whatl claim is:
1. A manually operable switch for surface attachment and having at least one transparent area covering but not obscuring visual information area displayed on a display area of the surface beneath the switch, comprising:
a. an elastically bendable conducting strip having a shape not obscuring information in the display area when placed in a preferred position near the display area, and having display and viewer sides;
b. a plurality of attachment standoffs attached at spaced intervals to the display side of the bendable conducting strip;
c. a plurality of insulating standoffs, each attached on the viewer side of the bendable conducting strip between the attachment points of the plurality of attachment; and
d. an actuating member having a conductive area and at least one transparent viewing area and attached to the insulating standofis in a position i. allowing relative movement of the actuating member toward the plurality of attachment standoffs causing elastic bending of the bendable conducting strip and electrical contact between it and the conductive area, and
causing the display area to be at least partly covered by the viewing area when the bendable conducting strip is in its preferred position near the display area.
2. The apparatus of claim 1 wherein the bendable conducting strip comprises a metal strip having an open area.
3. The apparatus of claim 1 wherein the bendable conducting strip comprises a first U-shaped conductive strip suitable for at least partially surrounding the display area.
4. The apparatus of claim 3 wherein the actuating member comprises a transparent strip and a second U-shaped conductive strip having substantially the dimensions of the first U- shaped conductive strip, and attached to the actuating member.
5. The apparatus of claim 4 including an adhesive coating for attaching the second U-shaped conductive strip to the actuating member.
6. The apparatus of claim 3 wherein the actuating member comprises a transparent strip having a viewing area larger than the display area dimensions, and a second U-shaped conductive strip having substantially the dimensions of the first U- shaped conductive strip and attached to the periphery of the transparent strip.
7. The apparatus of claim 3 wherein each insulating standoff comprises an insulating shim having a width no greater than the width of an arm of the U-shaped conductive strip, a length small compared to the interval between successive insulating standoff attachment points and a thickness smaller than that of the plurality of attachment standoffs.
8. The apparatus of claim 1 wherein the bendable conducting strip is formed from a beryllium copper alloy.
9. The apparatus of claim 1 including adhesive coatings for attaching the standoffs to the respective surfaces of the actuating member, bendable conducting strips, and surface.
10. The apparatus of claim 1 wherein the actuating member comprises a transparent member and a pair of conductive strips attached along the edge of the transparent area of the transparent member.
whereby said bendable conducting strip is flexed between adjacent attachment standoffs by said insulating standoffs upon closing said switch.
13. The apparatus of claim 1 wherein the bendable conducting strip comprises a first l-shaped conductive strip and the conductive area comprises a second l-shaped conductive strip attached lengthwise to one face of the actuating member.