US3618072A

US3618072A - Thin-line digicator display

Info

Publication number: US3618072A
Application number: US789443A
Authority: US
Inventors: Bruce G Kirkpatrick; Rene F De Groof
Original assignee: Discon Corp
Current assignee: Discon Corp
Priority date: 1969-01-07
Filing date: 1969-01-07
Publication date: 1971-11-02
Anticipated expiration: 1988-11-02
Also published as: GB1279136A

Abstract

A thin, multisegment, incandescent lamp display which permits mounting of the device on the front surface of a control panel with no protrusions behind the front panel except wire or connecting terminations. Incandescent lamps with axially mounted filaments are directly viewed. The lamps are outside the apparatus on which the device is mounted and therefore do not contribute to internal heating.

Description

U n ite [72] Inventors [21 Appl. No. [22] Filed [45] Patented [73] Assignee [54] THIN-LINE DIGICATOR DISPLAY Primary Examiner- Richard Murray Attorney-Leonard H. King ABSTRACT: A thin, multisegment, incandescent lamp display which permits mounting of the device on the front surface ofa control panel with no protrusions behind the front panel except wire or connecting terminations. Incandescent lamps with axially mounted filaments are directly viewed. The lamps are outside the apparatus on which the device is mounted and therefore do not contribute to internal heating.

10 Claims, 6 Drawing Figs.

[52] U.S.C1 340/336, 340/383 [51] lnt.Cl G095 9/32 [50] Field ollSearch 340/336, 380, 382, 383

ll Tllilllhl-LllhllE llltl GllCATtJJlll lll libl lbhlt This invention relates to illuminated displays of the type wherein lamps are selectively energized to create a display.

lFlACliGhQUND 01F TlillE ll li lEl lTl Ol l Seven-segment displays are commonly employed as readouts for a range of instruments such as digital voltmeters, computers, and the lilte. in order to obtain unitorm lighting, is has been common practice to employ light guides for transmitting and fanning out the light from the tip of the conventionally tubular bulb-shaped incandescent lamp to the bar surface of the display segment. Such designs are shown, for example, in US. Pat. l lo. 3,252,lil and 3,261,013. The light output of this prior type of device was generally low and it was difficult to view in a well-lighted environment. Another of the problems faced by the user of such devices is that because of the light guide they generally extended for a great distance in the direction perpendicular to the plane of the display.

in the present design, atrial filament-type lamps are employed for direct viewing and constitute the actual light bar segment. Thus the thickness of the display in a direction perpendicular to the plane of the display can be extremely small. For example, the overall dimension for a 1-inch character is but 0.265 inches thiclr by 1.43 inches high by 0.937 inches wide, when using light bars 0.075 inches wide. The display is legible at a distance of 50 feet in bright ambient daylight.

in addition, complete words may be printed on neutral or colored filters and may be used to indicate various functions, such as High Voltage On, Signal Received, a malfunction indication, Standby, Operate, etc., and may be placed in various arrangements in the housing.

Accordingly, it is a primary object of this invention to provide a segmented bar-type readout utilizing axial lamps for illumination.

it is another object of this invention merit display of thin dimension.

it is a further object of this invention to provide a multisegment display with increased light output for greater visibility.

Another object is to provide multiple readout displays where warnings of malfunctions or procedural functions may be displayed in color and combined with numerical displays.

A still further object of this invention is to provide a multisegment display with increased output and the capability of conveniently replacing individual lamps.

These and other objects, features and advantages of the invention will, in part, be pointed out with particularity and will, in part, become obvious from the following more detailed description ol the invention, talren in conjunction with the accompanying drawing which forms an integral part thereof.

BlllElF DESCRllTlON OlF TlrllE DRAWING in various lFlGS. of the drawing, designate lilre parts.

Flt ii is a front view of the display;

FIG. 2! is a top view of the display partially broken away along line Ji -fl, shown on a typical panel;

l lG. El is a cross-sectional view of the display talren along line 3l-El;

FlG. d is a longitudinal, elevational view of an axial lamp;

Flt}. 5 is a rear view of the main housing showing terminal means; and

Fit]. 6 is isometric view, partially brolren away, of a printed circuit board with several lamps mounted thereon.

to provide a multiseglike reference characters lJEbClTlPTlON 0h TllllE EMBODIMENT Referring to the drawing, in H6. ii there is shown a typical thin-line display ill comprising this invention, the display it) providing a multisegment lighted numeric readout l2 and a plurality of functional readouts id.

The display ill is housed in a frame in that is comprised of longitudinal sections ill and end sections 20. Sections of the frame 16 are provided with grooves 22 (HO. ii) that are dimensioned to accept a printed circuit assembly 2 41 (HG. t5) which includes a conventional printed circuit board 26 having conducting pathways on the rear surface thereof. The leads of a plurality of axial filament extend through the printed circuit board as and are electrically connected to selected ones oi the conducting pathways 2d. When selected ones of the lamps Elli are energized, recognizable character is formed. One or more single-ended lamps may also be mounted on the printed circuit board Jlti so that when it is energized a decimal point is represented. Since the singleended lamp 32 operates at a lower voltage than the axial filament lamps 30, a voltage-dropping resistor 341 is connected in series with the lamp 332 so that the display lllll operates from one potential. The foregoing describes the construction of the numeric readout T2. The functional readouts are provided by imprinting selected axial filament lamps 3t) with suitable indicia as shown, for example, in Flt l.

A baffle member 36 is positioned over the printed circuit board as and is provided with a plurality of suitably sized and located apertures 33 which receive the axial filament lamps 30. The sides of the apertures 38 act to restrict the light emitted by the axial filament lamps Elli when they are energized. It is important to note that the filaments of lamps Sill are aligned in a common plate and, in combination with the sides of the apertures 3%, provide for substantially improved readability of the display llll.

Mounting studs ll are provided in the frame to and may be used for mounting the display ll l to a flat surface such as a panel l in cooperation with nuts Mounting may be accomplished by drilling or punching simple panel openings and does not require carefully machined openings as for certain prior art devices.

The baffle member 36 described above is shown in the drawing as being plastic (nonconductive). When this construction is used only one insulator dd is required between the rear surface of the printed circuit assembly and the confronting surface of the panel P. The insulating material may be a sheet of mylar. lilowever, the baffle member as may also be made of a suitable metal and in this instance, an insulator would be required between the rear surface of the baffle member 36 and the confronting surface of the printed circuit assembly.

A in of terminal pins as are suitably secured to the printed circuit assembly Ii -l and extend rearwardly thereof through apertures ill in the insulator dd. A conventional connector 50 is received in an opening in the panel. l and mates with the terminal pins d6. Another connector (not shown) is electrically connected to a suitable source of power and is adapted to mate with the connector till. it should be understood that other terminal and connector formations may be used, including wiring directly to the terminal pins.

The resulting assembly is very compact and may be in the order of0.3 inches thiclr by 1% inches high by 0.9 inches wide, with light bars or lamps which are only 0.09 inches wide. The display can be produced in character sizes of approximately one-fourth of an inch high to several inches high and character styles can be either alphanumeric or digital type.

A neutral or color filter 54 is provided over the face of the unit and serves to give a more uniform appearance to the light output as well as preventing dust or other foreign materials from entering. in addition, complete words or functions may be printed instead of one of the alphanumerical or digital dis plays.

As described heretofore, the display till may be formed of individual frame and battle members. Alternatively, frame to and the baffle member 1% may be extruded in aluminum or may be molded of a synthetic resin such as polycarbonate, phenolic or other suitable resin. The display may be injection molded, die-cast or extruded in a strip into which may be stamped a multitude of openings of various configurations to receive the lamps. The printed circuit board may be a separate assembly or may be attached or deposited on the baffle member 36. Using current thiclr film techniques, the printed circuit wiring and even the logic driving circuit may be deposited on the rear of the housing. The display may be cut into individual characters if desired, or, by placing several strips together, multicharacter displays or functions may be formed.

It is desirable to coat the inside of the apertures 38 with a reflective white paint to reflect the light. This results in a brighter, more uniform image.

If it is desired to wire wrap wires to connector pins 46, instead of using a connector, then a square pin 46 can be employed.

Accordingly, it will be appreciated that a flat, compact display is provided which can be mounted on the outside of the case for an electronic device. In this location the bulbs are outside the case and do not contribute to heating of components inside the case. Further, since the bulbs are on the outside they do not tend to overheat which would reduce their life.

While only the presently preferred embodiment of the invention has been illustrated, it is understood that alterations, changes and modifications may be made without departing from the true scope and spirit of the invention.

What I claim as new and desire to secure by Letters Patent is:

l. A thin, illuminable display adapted to be mounted on a panel, said display comprising;

a. a printed circuit board having first and second surfaces;

b. a plurality of lamps each having a tubular housing positioned coaxially about axially extending filaments that terminate in leads outside of said housing, said lamps being mounted on said first surface of said printed circuit board with the filaments of said lamps being aligned in a common plane, said leads 'of said lamps extending through said printed circuit board, selected ones of said lamps being adapted to be energized in response to a given set of input signals whereby said energized lamps form a recognizable character;

0. a plurality of conducting pathways formed on said second surface of said printed circuit board, selected portions of said pathways being electrically connected to said leads of said lamps; and

d. baffle means positioned proximate said lamps for restricting the light emitted thereby through a said cylinder wall from being viewed from other than a specific segment of the recognizable character.

2. The device in accordance with claim 1 wherein said baffle means is a nonconductive plate having apertures therein to receive said lamps, the sides of the apertures acting to restrict the light, said baffle means also having means integral therewith for mounting said device on the panel.

3. The device in accordance with claim 1 wherein said baffle means is a conductive plate having apertures therein to receive said lamps, the side of the apertures acting to restrict the light, there being further included insulating means positioned between said baffle means and said first surface of said printed circuit board and between said second surface of said printed circuit board and the panel.

4. The device in accordance with claim 3 further including frame means for supporting said baffle means and said printed circuit board, said frame means including means for mounting said device on the panel.

5. The device in accordance with claim 1 further including filter means positioned over said lamps.

6. The device in accordance with claim 1 wherein at least one of said lamps includes indicia printed thereon.

7. The device in accordance with claim 1 further including at least one single-ended lamp mounted on said printed circuit board, said single-ended lamp representing a decimal point when energized.

8. The device in accordance with claim 7 further including a voltage-dropping resistor connected in series with said singleended lamp.

9. The device in accordance with claim 1 wherein said printed circuit board includes terminal means adapted to be connected to an external source of electrical power.

10. The device in accordance with claim 9 wherein said terminal means comprises a plurality of pins in electrical contact with selected portions of said conducting pathways and plug means adapted to mate with said pins, said plug means having portions to be connected to a suitable source of electrical power.

* i i k l

Claims

1. A thin, illuminable display adapted to be mounted on a panel, said display comprising; a. a printed circuit board having first and second surfaces; b. a plurality of lamps each having a tubular housing positioned coaxially about axially extending filaments that terminate in leads outside of said housing, said lamps being mounted on said first surface of said printed circuit board with the filaments of said lamps being aligned in a common plane, said leads of said lamps extending through said printed circuit board, selected ones of said lamps being adapted to be energized in response to a given set of input signals whereby said energized lamps form a recognizable character; c. a plurality of conducting pathways formed on said second surface of said printed circuit board, selected portions of said pathways being electrically connected to said leads of said lamps; and d. baffle means positioned proximate said lamps for restricting the light emitted thereby through a said cylinder wall from being viewed from other than a specific segment of the recognizable character.

8. The device in accordance with claim 7 further including a voltage-dropping resistor connected in series with said single-ended lamp.