U.S. patent number 3,768,188 [Application Number 05/226,458] was granted by the patent office on 1973-10-30 for readout.
This patent grant is currently assigned to Daktronics, Inc.. Invention is credited to Paul A. Espeset, Aelred J. Kurtenbach, James B. Morgan.
United States Patent |
3,768,188 |
Kurtenbach , et al. |
October 30, 1973 |
READOUT
Abstract
A seven-segment readout of the "dot" segment type in which light
for each dot is coupled from a lamp through a light guiding
cylinder sandwiched between a lamp board holding the lamp and a
light diffusion member to a dot defining aperture of a faceplate,
which dot defining apertures are configured to form the segments of
a readout.
Inventors: |
Kurtenbach; Aelred J.
(Brookings, SD), Morgan; James B. (Brookings, SD),
Espeset; Paul A. (Los Angeles, CA) |
Assignee: |
Daktronics, Inc. (Brookings,
SD)
|
Family
ID: |
22848983 |
Appl.
No.: |
05/226,458 |
Filed: |
February 15, 1972 |
Current U.S.
Class: |
40/451;
40/573 |
Current CPC
Class: |
G09F
9/33 (20130101); G09F 9/307 (20130101) |
Current International
Class: |
G09F
9/307 (20060101); G09F 9/33 (20060101); G09f
013/06 () |
Field of
Search: |
;40/13E,13K,132D
;340/378R,381 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Michell; Robert W.
Assistant Examiner: Pitrelli; John F.
Claims
What is claimed is:
1. A dot segment readout comprising:
A. a faceplate having apertures therein defining the dots of the
segments of a readout;
B. a light diffusion member underlying the faceplate and
coextensive in area with at least each of said apertures;
C. a light guiding cylinder for each said aperture, said cylinder
having a length approximately equal to the width of said
aperture;
D. a cylinder locating plate having apertures both in registration
with the apertures of said faceplate and of dimensions for
accepting said light guiding cylinders to hold said cylinders in
axial alignment with said faceplate apertures;
E. a lamp board sandwiching said cylinders between said light
diffusion member and said board, said board having a lamp aperture
over each cylinder and having an electrical conducter proximate
each lamp accepting aperture;
F. a lamp in each lamp board aperture, the end area of each of
which lamps is approximately one-eighth of the cylinder
cross-sectional area, each of which lamps includes a rim for
holding the lamp in said lamp accepting aperture and for making
electrical contact with a said electrical conducter;
G. a back plate assembly for holding said lamps in said lamp
apertures and for providing an electrical contact to each of said
lamps:
H. fastening means for holding the faceplate, light diffusion
member, light guiding cylinders, cylinder locating plate, lamp
board, lamps, and backplate assembly together as a unitary dot
segment readout assembly.
2. A readout according to claim 1 wherein
said faceplate dot defining apertures are configured to form the
segments of a generally angular figure-eight seven-segment
readout;
said cylinder is a circular tube; and
said diffusion member is a polyester film.
3. A readout according to claim 2 wherein
said circular tube has a length of five-eighths of an inch and a
diameter of five-eighths of an inch; and
said diffusion member is 0.003 inch thick double matte polyester
tracing film.
4. A readout according to claim 1 wherein
said electrical conductors of said lamp board comprise printed
circuit paths, which paths interconnect the electrical conductors
of all lamp apertures of a segment, and which paths include a
circuit path which leads to an edge of the lamp board to facilitate
selective energization of the readout segments; and
said electrical contacts provided by said back plate assembly to
each of said lamps are electrically common.
5. A readout according to claim 4 wherein
said cylinder is a circular tube; and
said diffusion member is a polyester film.
6. A readout according to claim 5 wherein
said circular tube has a length of five-eighths of an inch and a
diameter of five-eighths of an inch;
said diffusion member is 0.003-inch thick double matte polyester
tracing film; and
said back plate assembly comprises an electrically conductive plate
having electrically conductive spring contacts secured thereto in a
pattern in registration with the faceplate segment dot apertures
whereby when the back plate assembly is urged toward the lamp board
by said fastening means, said spring contacts are compressed
against the base of said lamps to hold the lamps in the lamp board
and to provide a common electrical path to all bases through paths
comprising the electrically conductive spring contacts and
electrically conductive plate.
7. A readout according to claim 6 wherein
said cylinder locating plate comprises a flat plate having
apertures therein for accepting said cylinders and having flanges
extending therefrom to space the flat plate from said faceplate
whereby said cylinders are held stably in the apertures of said
flat plate in axial alignment with an axis normal to the faceplate
surface.
8. A readout according to claim 7 further comprising
J. a color filter interposed between said faceplate and said
diffusion member.
9. A readout according to claim 8 wherein
each of said faceplate, filter, diffusion member, cylinder locating
plate, lamp board, and back plate include a pair of aligned
apertures; and
said fastening means comprises a pair of bolts each of which is
passed through one of said aligned holes; a nut on each bolt turned
down against the cylinder locating plate whereby the locating plate
is secured to the faceplate; a nut on each bolt turned down against
the lamp board whereby the lamp board sandwiches the cylinders
between itself and the light diffusion member and forces the light
diffusion member, color filter, and faceplate into intimate
contact; and a nut on each bolt turned down against the back plate
assembly whereby the back plate assembly contacts hold the lamps in
the lamp board assembly to provide a unitary dot segment readout
assembly.
10. A readout according to claim 1 wherein
said back plate assembly comprises an electrically conductive plate
having electrically conductive spring contacts secured thereto in a
pattern in registration with the faceplate segment dot apertures
whereby when the back plate assembly is urged toward the lamp board
by said fastening means, said spring contacts are compressed and
press against the base of said lamps to hold the lamps in the lamp
board and to provide a common electrical path to all bases through
paths comprising the electrically conductive spring contacts and
electrically conductive plate.
11. A readout according to claim 10 wherein
said electrical conductors of said lamp board comprise printed
circuit paths, which paths interconnect the electrical conductors
of all lamp apertures of a segment, and each of which paths
includes a circuit path which facilitates selective energization of
the associated readout segments.
12. A readout according to claim 11 wherein
said cylinder locating plate comprises a flat plate having
apertures therein for accepting said cylinders and having flanges
extending therefrom to space the flat plate from said faceplate
whereby said cylinders are held stably in the apertures of said
flat plate in axial alignment with an axis normal to the faceplate
surface.
13. A readout according to claim 1 further comprising
J. a color filter interposed between said faceplate and said
diffusion member.
14. A readout according to claim 13 wherein
said back plate assembly comprises an electrically conductive plate
having electrically conductive spring contacts secured thereto in a
pattern in registration with the faceplate segment dot apertures
whereby when the back plate assembly is urged toward the lamp board
by said fastening means, said spring contacts are compressed and
press against the base of said lamps to hold the lamps in the lamp
board and to provide a common electrical path to all bases through
paths comprising the electrically conductive spring contacts and
electrically conductive plate; and
said electrical conductors of said lamp board comprise printed
circuit paths, which paths interconnect the electrical conductors
of all lamp apertures of a segment, and each of which paths
includes a circuit path which facilitates selective energization of
the associated readout segments.
15. A readout according to claim 14 wherein
said cylinder locating plate comprises a flat plate having
apertures therein for accepting said cylinders and having flanges
extending therefrom to space the flat plate from said faceplate
whereby said cylinders are held stably in the apertures of said
flat plate in axial alignment with an axis normal to the faceplate
surface.
16. A readout according to claim 13 wherein
said lamp board comprises an electrically conductive plate; and
said back plate assembly comprises a printed circuit board carrying
printed circuit paths thereon and having electrically conductive
spring contacts secured thereto in a pattern in registration with
the faceplate segment dot apertures and in electrical contact with
said printed circuit paths; which paths facilitate selective
energization of each group of spring contacts corresponding to a
readout segment whereby when the back plate assembly is urged
toward the lamp board by said fastening means, said spring contacts
are compressed and press against the base of said lamps to hold the
lamps in the lamp board.
17. A readout according to claim 1 wherein
said cylinder locating plate comprises a flat plate having
apertures therein for accepting said cylinders and having flanges
extending therefrom to space the flat plate from said faceplate
whereby said cylinders are held stably in the apertures of said
flat plate in axial alignment with an axis normal to the faceplate
surface.
18. A readout according to claim 17 wherein
said back plate assembly comprises an electrically conductive plate
having electrically conductive spring contacts secured thereto in a
pattern in registration with the faceplate segment dot apertures
whereby when the back plate assembly is urged toward the lamp board
by said fastening means, said spring contacts are compressed and
press against the base of said lamps to hold the lamps in the lamp
board and to provide a common electrical path to all bases through
paths comprising the electrically conductive spring contacts and
electrically conductive plate; and
said electrical conductors of said lamp board comprise printed
circuit paths, which paths interconnect the electrical conductors
of all lamp apertures of a segment, and each of which paths
includes a circuit path which facilitates selective energization of
the associated readout segment.
19. A readout according to claim 17 wherein
said lamp board comprises an electrically conductive plate; and
said back plate assembly comprises a printed circuit board carrying
printed circuit paths thereon and having electrically conductive
spring contacts secured thereto in a pattern in registration with
the faceplate segment dot apertures and in electrical contact with
said printed circuit paths; which paths facilitate selective
energization of each group of spring contacts corresponding to a
readout segment whereby when the back plate assembly is urged
toward the lamp board by said fastening means, said spring contacts
are compressed and press against the base of said lamps to hold the
lamps in the lamp board.
20. A readout according to claim 1 wherein
said lamp board comprises an electrically conductive plate; and
said back plate assembly comprises a printed circuit board carrying
printed circuit paths thereon and having electrically conductive
spring contacts secured thereto in a pattern in registration with
the faceplate segment dot apertures and in electrical contact with
said printed circuit paths; which paths facilitate selective
energization of each group of spring contacts corresponding to a
readout segment whereby when the back plate assembly is urged
toward the lamp board by said fastening means, said spring contacts
are compressed and press against the base of said lamps to hold the
lamps in the lamp board.
Description
BACKGROUND AND HISTORY
The present invention relates in general to apparatus for the
optical display of information, and relates in particular to such
apparatus in a form commonly referred to as a seven-segment
readout.
In general, a seven-segment readout comprises seven optical
segments in a generally angular figure-eight configuration. Three
segments form the sides and top of the upper half of the
figure-eight; three other segments form the sides and bottom of the
lower half; and the seventh segment is common to the upper and
lower halves, forming the bottom of the upper half and the top of
the lower half. Through selective energization of the segments,
each of the Arabic number digits zero through nine are optically
displayed in a wellknown manner.
Most seven-segment readouts are either a fully illuminated segment
or "bar" segment readout in which the entire segment is illuminated
as nearly uniformly as possible, or a partially illuminated segment
or "dot" segment readout in which a series of illuminated dots form
each segment. The present invention relates specifically to a dot
segment readout.
Seven-segment readouts have, for many years, had widespread
application, including such types of applications as the digits of
various types of score-boards and the digits of display panels of
various electronic devices, for example, the display panels of
operator consoles of spaceship launch control equipment and data
processing equipment operator console display panels. Typically,
readouts of the former type application have a readout digit which
is several times larger in area than those of the latter
application. Although the present invention was specifically
developed as a readout of the former type, specifically as a
scoreboard readout, the invention is of broader application and
applies to readouts such as those of the latter type application as
well.
An object of the present invention is to provide a dot segment
readout, the individual dots of which are illuminated with a
high-intensity lamp, yet appear to be uniformly illuminated
throughout the dot area, all while providing a dot surface area
several times larger than the end area of the lamp to provide
large, clearly recognizeable dots which, in turn, provide readily
discernible segments.
Another object of the present invention is to provide a readout
assembly structure the components of which are low in cost, easy to
assemble, and easy to disassemble for maintenance such as lamp
replacement maintenance.
Yet another object of the present invention is to provide a readout
assembly which facilitates easy and low-cost electrical
inter-connection of the readout with the electronics which provides
selective energization and illumination of the segments.
SUMMARY OF THE INVENTION
Briefly, the invention comprises a dot segment readout assembly
having a faceplate, a light diffusion member underlying the
faceplate, and, if desired, a color filter interposed between the
faceplate and light diffusion member. The faceplate includes
apertures which define the dots of the readout segments. A cylinder
for each segment dot is positioned over the dot by a cylinder
locating plate and is held in place by a lamp board having
apertures through which lamps protrude into each cylinder to
provide a source of illumination for each dot. Each lamp includes
an electrically conductive rim at its base, not unlike the rim of a
firearms cartridge and each lamp-accepting aperture of the lamp
board is provided with an electrical conductor proximate thereto. A
back plate assembly is employed to hold the lamps in place in the
lamp board apertures to force the lamp rims into contact with a
said lamp board conductor proximate thereto. The back plate
assembly includes means for making electrical contact with each
lamp base, the lamp board conductor and back plate assembly thus
providing the two contacts or "leads" necessary to connect each
lamp into an electrical circuit and permit selective energization
of the lamps as required to illuminate the various combinations of
segments.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an exploded view of a preferred embodiment of a
seven-segment, angular, figure-eight dot segment readout according
to the present invention.
FIG. 2 is a sectional view of a portion of an assembled readout
illustrating the relationships of the components illustrated in
FIG. 1 when the components are assembled.
DETAILED DESCRIPTION OF INVENTION
The invention shall now be described with reference to FIGS. 1 and
2 which illustrate different views of a preferred embodiment of the
invention developed specifically for a scoreboard application.
Referring now to FIG. 1, an exploded view is shown. A faceplate 10
is shown to have apertures therein, one of which is designated 12,
defining the dots of the seven segments of a generally angular
figure-eight. For the preferred embodiment, faceplate 10 is a
parallelogram having major sides 83/4 inches long and minor sides
57/8 inches long; the sides form an acute angle of about
83.degree.; the plate 10 is fabricated from 0.04-inch thick vinyl
clad steel; and the apertures are one-half inch diameter on 1-inch
centers in rows and columns parallel to the faceplate sides.
In the preferred embodiment, a color filter 20 was employed between
Faceplate 10 and a light diffusion member 30. Such filters are well
known in the art and are commonly used to add clarity to a readout.
They may be any of a variety of materials. For the preferred
embodiment, filter 20 is one-eighth inch thick red or green or
amber colored plexiglass, manufactured by the Rohm and Haas Company
Philadelphia, Pa. and sold as their catalogue numbers 2433, 2092,
or 2422, respectively.
Light diffusion member 30 is an important element of the present
invention, in that it is a significant factor in providing uniform
intensity illumination throughout each dot area. Conveniently, a
single sheet of light diffusing material may be used to provide a
light diffusion member for all dots. For the preferred embodiment,
tracing film such as 0.003-inch thick, double matte, polyester
tracing film sold by the Charles Bruning Company as their catalogue
number 44-132 was found to provide excellent results.
A light guiding cylinder 40 is provided for each segment dot. The
cylinder length is approximately equal to the cylinder width to aid
in providing uniform dot intensity. For the preferred embodiment,
cylinders 40 are cut from circular tubing into 0.625-inch lengths
of 0.01-inch thick by 0.625-inch outside diameter brass tubing. Use
of such cylinders facilitates employment of high-intensity lamps
because the cylinders transmit heat from the lamps into the air
spaces between the cylinders. Metallic cylinders of course are
efficient radiators and also can withstand greater heat than
cylinders of other materials such as plastic.
A cylinder locating plate 50 includes apertures, one of which is
designated 52, in registration with the faceplate apertures.
Apertures 52 each accept a cylinder 40 to locate the cylinder with
respect to its corresponding faceplate aperture. As shown in FIG.
1, in the preferred embodiment, cylinder locating plate 50 includes
flanges 54 and 56 which, as shall be more clearly apparent in FIG.
2, abut faceplate 10 to raise the surface of locating plate 50
sufficiently above light diffusing member 30 that cylinders 40 are
held stably in plate 50 so as not to cant. In the preferred
embodiment shown, flanges 54 and 56 are 0.25 inches and the
apertures are five-eighths inch holes drilled in 0.04 inch thick
terne plate steel.
A lamp board 60 sandwiches cylinders 40 between itself and the
light diffusing member 30. The lamp board 60 includes a lamp
aperture over each cylinder and also includes an electrical
conductor proximate each lamp aperture.
In the preferred embodiment, lamp board 60 comprises an etched
printed circuit board fabricated from 0.062-inch thick epoxy board
clad on one side with 0.0027-inch thick copper; etched printed
circuit paths on the board form a conductive ring around each lamp
aperture, such as ring 62; and all rings corresponding to lamps of
the same segment are common to a conduction path, such as
conduction path 64. As shown, the conduction paths lead to an edge
of board 60 to facilitate connection of the paths to lamp selection
circuitry (not shown) all or part of which circuitry can be
included on the lamp board. It will be appreciated that such
connection may be the easiest and least expensive of any of a
number of conventional means, including wire-wrap terminals, solder
terminals, male-female engaging terminals, and standard male-female
printed circuit card connectors, the particular connection employed
being immaterial to the present invention. A lamp 66 completes the
lamp board assembly. For the preferred embodiment, IEE standard No.
387 AS25 lamps rated at 28.0 volts and 0.040 amps and having an end
area about one-eighth the area of the cylinders are used.
Back plate assembly 70 serves to hold the lamps in the lamp
apertures and provides an electrical contact to each lamp.
For the preferred embodiment, assembly 70 is fabricated from 0.04
thick terne plate steel in the same manner as the cylinder locating
plate 50 to realize economies in the manufacture of the readout by
minimizing the number of different manufacturing operations.
Attached to the steel plate is a common terminal 72 and a plurality
of rivet mounted spring contacts, there being a spring contact for
each lamp. For the preferred embodiment, spring contacts 74 were
the Lewis, 0.22-inch outside diameter by three-eighths-inch
compression contacts. It will be appreciated that upon forcing of
the spring contacts 74 into contact with the bases of lamps 66, all
lamp bases are connected to common through a path consisting of a
contact 74, back plate 70 and common terminal 72, thereby
permitting selective activation of any segment group of lamps by
completing the electrical circuit through the appropriate
connectors of lamp board 60.
Fastening means hold the foregoing described components together as
a unitary dot segment readout assembly.
For the preferred embodiment, assembly is facilitated by a pair of
holes 90 and 92 in each of face-plate 10, color filter 20,
diffusion member 30, cylinder locating plate 50, lamp board 60, and
back plate 70. A pair of bolts, 94 and 96 (No. 10, three-sixteenths
inch in diameter by 13/4 inches long) secure the assembly by means
of hex nuts, 98 and 100, and lock washers, 102 and 104, at the
locating plate 50 level of assembly; by hex nuts, 106 and 108, and
lock washers, 110 and 112, at the lamp board 60 level of assembly;
and by wing nuts, 114 and 116, at the back plate 70 level of
assembly. Non-conductive, press-in grommets, 118 and 120, in back
plate 70 insulate bolts, 94 and 96, from the back plate.
The relationships of the various components in their assembled
condition are shown in FIG. 2, a sectional view taken along the
axis of a cylinder 40. Referring now to FIG. 2, the flange 54 is
shown to position locating plate 50 with reference to faceplate 10
through the action of nut 98 and nut 100 (not shown). Nuts 106 and
108 (not shown) force lamp board 60 onto cylinders 40 to press the
other end of the cylinders against diffusion member 30, thereby
forming nearly light tight seals on both ends of the cylinders and
forcing diffusion member 30, color filter 20, and face-plate 10,
into intimate contact with each other. The balance of the assembly
is secured by wing nuts 114 and 116 (not shown) which force the
back plate 70 downwardly along the shafts of bolts 94 and 96 (not
shown) to compress the springs of spring contacts 74, thereby
insuring good electrical contact between the spring contacts 74 and
the bases of lamps 66 and between the lamp rims and the circuitry
rings around the lamp apertures.
Having taught how to make and use the invention by means of the
foregoing description of the illustration of a preferred embodiment
of the invention as shown in FIGS. 1, and 2, the invention for
which letters patent are sought shall now be defined by means of
the following claims.
* * * * *