U.S. patent number 3,917,972 [Application Number 05/381,796] was granted by the patent office on 1975-11-04 for multi-position indicator display tube.
This patent grant is currently assigned to Sony Corporation. Invention is credited to Shoichi Muramoto, Akio Ohgoshi, Akira Yamanaka, Yuzuru Yanagisawa.
United States Patent |
3,917,972 |
Yanagisawa , et al. |
November 4, 1975 |
Multi-position indicator display tube
Abstract
An indicator display tube in which indicator electrode units,
each consisting of anode and cathode segments, lie in the same
plane and in which all of the cathode segments are simultaneously
energized and the anode segments are energized on a time sequential
basis in such a manner that only the indicator electrode unit
having its anode segments energized will glow at a particular time.
The cathode segments of each indicator unit are connected in
parallel. The indicator display tube has barrier segments for
preventing accidental discharge of adjacent indicator electrode
units which would produce erroneous message displays. At least the
cathode but preferably all of the segments are formed of a silver
paste coated with nickel. The base material on which the silver
paste is coated is glass. This arrangement prevents sputtering.
Inventors: |
Yanagisawa; Yuzuru (Fujisawa,
JA), Ohgoshi; Akio (Tokyo, JA), Yamanaka;
Akira (Fuchu, JA), Muramoto; Shoichi (Tokyo,
JA) |
Assignee: |
Sony Corporation (Tokyo,
JA)
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Family
ID: |
27303280 |
Appl.
No.: |
05/381,796 |
Filed: |
July 23, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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365334 |
Jun 4, 1973 |
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177990 |
Sep 7, 1971 |
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Foreign Application Priority Data
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Sep 11, 1970 [JA] |
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45-80378 |
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Current U.S.
Class: |
313/519;
313/590 |
Current CPC
Class: |
H01J
17/491 (20130101) |
Current International
Class: |
H01J
17/49 (20060101); H01J 061/067 (); H01J
061/66 () |
Field of
Search: |
;313/517,519,190,218,217
;315/169R,169TV |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Demeo; Palmer C.
Attorney, Agent or Firm: Hill, Gross, Simpson, Van Santen,
Steadman, Chiara & Simpson
Parent Case Text
This application is a division of our copending application, U.S.
Pat. Ser. No. 365,334, filed June 4, 1973, and which in turn was a
continuation of our application U.S. Pat. Ser. No. 177,990, filed
Sept. 7, 1971, now abandoned.
Claims
We claim:
1. An indicator display tube comprising:
a plate of an insulating material;
a plurality of interconnecting leads formed on said plate;
a first insulating layer formed on said plate over said plurality
of interconnecting leads with windows aligned with said
interconnecting leads;
a plurality of indicator units formed on said first insulating
layer and each consisting of a number of strip conductive elements
and a plurality of selecting leads on said first insulating layer
with said indicator units and said selecting leads connected to
corresponding ones of said interconnecting leads through said
windows respectively; certain of said strip conductive elements
comprising cathode gaseous discharge sustaining display electrodes
and others of said strip conductive elements comprising anode
gaseous discharge sustaining and counter electrodes;
barrier means of electrically conductive material formed on said
first insulating layer and formed with openings in which said
associated strip conductive elements of said indicator units are
mounted;
a second insulating layer formed on said selecting leads;
a transparent cover attached to said plate and forming an envelope
for enclosing said indicator units and barrier means;
an ionizable gas sealed in said envelope, said first insulating
layer being formed of glass and said strip conductive elements and
said selecting leads being formed of silver;
said first insulating layer of glass formed partially over the
edges of said strip conductive elements to leave a portion thereof
uncovered, a first layer of nickel deposited over said uncovered
portions of said conductive elements, and a second layer of nickel
formed over said first layer of nickel and extending partially over
said first insulating layer of glass.
2. An indicator display tube comprising:
a plate of an insulating material;
a plurality of interconnecting leads formed on said plate;
a first insulating layer formed on said plate over said plurality
of interconnecting leads with windows aligned with said
interconnecting leads;
a plurality of indicator units formed on said first insulating
layer and each consisting of a number of strip conductive elements
and a plurality of selecting leads on said first insulating layer
with said indicator units and said selecting leads connected to
corresponding ones of said interconnecting leads through said
windows respectively; certain of said strip conductive elements
comprising cathode gaseous discharge sustaining and display
electrodes and others of said strip conductive elements comprising
anode gaseous discharge sustaining and counter electrodes,
barrier means of electrically conductive material formed on said
first insulating layer and formed with openings in which said
associated strip conductive elements of said indicator units are
mounted;
a second insulating layer formed on said selecting leads;
a transparent cover attached to said plate and forming an envelope
for enclosing said indicator units and barrier means;
an ionizable gas sealed in said envelope, said first insulating
layer being formed of glass and said strip conductive elements and
said selecting leads being formed of silver;
said first insulating layer of glass formed partially over the
edges of said strip conductive elements to leave a portion thereof
uncovered;
a second layer of silver deposited over said uncovered portions of
said strip conductive elements and partially overlying said first
insulating layer;
a layer of copper overlying said second layer of silver, and a
layer of nickel overlying said second layer of silver and extending
to said second insulating layer.
3. An indicator display tube comprising:
a plate of an insulating material;
a plurality of interconnecting leads formed on said plate;
a first insulating layer formed on said plate over said plurality
of interconnecting leads with windows aligned with said
interconnecting leads;
a plurality of indicator units formed on said first insulating
layer and each consisting of a number of strip conductive elements
and a plurality of selecting leads on said first insulating layer
with said indicator units and said selecting leads connected to
corresponding ones of said interconnecting leads through said
windows respectively; certain of said strip conductive elements
comprising cathode gaseous discharge sustaining and display
electrodes and others of said strip conductive elements comprising
anode gaseous discharge sustaining and counter electrodes;
barrier means of electrically conductive material formed on said
first insulating layer and formed with openings in which said
associated strip conductive elements of said indicator units are
mounted;
a second insulating layer formed on said selecting leads;
a transparent cover attached to said plate and forming an envelope
for enclosing said indicator units and barrier means;
an ionizable gas sealed in said envelope, said first insulating
layer being formed of glass and said strip conductive elements and
said selecting leads being formed of silver;
said first insulating layer of glass formed partially over the
edges of said strip conductive elements to leave a portion thereof
uncovered, a layer of platinum overlying said uncovered portions of
said conductive elements and extending partially over said first
insulating layer of glass, and a coating of nickel overlying said
layer of platinum and extending downwardly to said first insulating
layer of glass.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to an indicator display tube and,
in particular, to a novel indicator display tube and to a method
for making it.
2. Description of the Prior Art
Generally, indicator display tubes, which are of the type including
a plurality of indicator units mounted inside a transparent
envelope for displaying numerals, symbols, letters or the like,
have been used with electronic counters and other various
indicating devices.
U.S. Pat. Ser. No. 3,588,571 discloses an indicator display tube of
the type having a plurality of indicator units, each consisting of
an anode and a plurality of cathode segments, formed on an
insulating plate with the cathode segments in each unit connected
in common to those in the other units and connected to common
energizing leads but in which the anodes are connected to separate
energizing leads which are led out of the envelope. This indicator
display tube has advantages in that the number of the leads
required is smaller than that of the earlier prior art tubes.
SUMMARY OF THE INVENTION
The present invention relates to a particular structure for the
cathode, anode, and barrier segments of an indicator display tube,
which indicator display tube is of the type having a number of
indicator units whose anode and cathode segments are formed in a
common plane, and which additionally includes barrier segments to
prevent accidental discharges. The structure of the cathode, anode
and barrier segments is in the form of a silver paste formed on a
glass base, and which silver paste is coated with nickel to prevent
sputtering. It is preferable that at least the cathode segments of
the unit be formed in this manner.
It is an object of the present invention to provide a novel
indicator display tube having long life, and in which any
sputtering from the surface of the electrodes is substantially
reduced.
Other objects, features and advantages of the present invention
will become apparent from the following description, taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view schematically illustrating an indicator
display tube having novel electrode structure of the present
invention;
FIG. 2 is a plan view of the backing plate with a plurality of
interconnecting leads formed thereon;
FIG. 3 is a plan view of the backing plate of FIG. 2 with an
insulating layer formed over the interconnecting leads;
FIG. 4 is a plan view of the backing plate of FIG. 3 with a
plurality of indicating units and selecting leads formed over the
insulating layer;
FIG. 5 is a plan view of the backing plate of FIG. 4 with an
insulating layer formed thereon;
FIG. 6 is a sectional view taken on line VI--VI of FIG. 1;
FIG. 7 is an enlarged fragmentary sectional view of the backing
plate of FIG. 5; and
FIGS. 8, 9 and 10 are sectional views, similar to FIG. 7, showing
other modified forms of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is illustrated generally one example of a gaseous
glow type indicator display tube 1 produced according to this
invention. The indicator display tube 1 is made up of a base plate
2 of an insulating material as, for example, glass. A plurality of
indicator units 40, 41, 42, 43, 44, and 45, of the same pattern are
formed by printing techniques on the base plate 2 in alignment with
one another and a transparent cover plate 3, as of glass, is
attached at its periphery in an air-tight manner to a glass base
plate 2 and its center is spaced a predetermined distance from the
indicator units.
One form of structure in which the present invention may be
embodied is disclosed in FIGS. 2 to 6. Here there is shown an
enlarged plan view of the base plate 2 and illustrates a plurality
of interconnecting leads 10 to 18 which are formed on the
insulating base plate 2 by suitable thin film techniques such as,
for example, by printing. It is to be particularly noted that the
interconnecting leads 10 to 18 are grouped so that they will align
with indicator units to be formed above a particular group. Thus,
the interconnecting leads for the first indicator unit are
designated by numerals 10 to 18 and the interconnected leads for
the second unit are designated by numerals 10' to 18'. The
interconnecting leads are formed of silver paste which adheres well
to the glass base plate 2.
After the interconnecting leads are formed by printed circuit
techniques on the base plate 2, the plate and leads are baked to
provide suitable bonding.
It is to be realized that the lengths of the interconnecting leads
10 to 18 are such that they will be capable of interconnecting the
cathode and anode elements of the indicator units to suitable
selecting leads as will become more apparent in the
description.
FIG. 3 is a plan view of the base plate 2 in which a glass
insulating layer 20 has been deposited on the base plate 2 so as to
cover a substantial portion of the interconnecting leads 10 to 18.
The insulating layer 20 may be formed by a glass coating method by
applying glass coating by spraying two or three times and then by
drying it to provide it with a suitable insulating coating 20 over
the interconnecting leads.
Windows are formed in the insulating layer 20 at opposite ends at
each of the interconnecting leads 10 to 18 so as to allow
electrical conducting paths to be formed through the insulating
layer 20 to the interconnecting leads 10 to 18. For example,
windows 30a and 30b are formed through the insulating layer 20 at
opposite ends of the interconnecting lead 10. Windows 31a and 31b
are formed at opposite ends of the interconnecting lead 11 and
additional windows 32a and 32b through 38 a and 38b are
respectively formed at opposite ends of leads 12 to 18. Additional
windows intermediate the ends of lead 14 are formed and are
designated 34c and 34d.
It is to be realized, of course, that the windows formed through
the layer 20 are formed for each of the indicator units although
they are only particularly numbered in FIG. 3 for the first
indicator unit.
FIG. 4 illustrates the next step of the method of making the
indicator unit and illustrates a plurality of indicating units 40
to 45 which are formed on the top of the insulating layer 20.
In the next step, the plurality of indicator units 40 to 45 (the
number depending upon the desired number) are formed on the
insulating layer 20 and aligned with the windows through the layer
20 so that electrical contact will be made with the interconnecting
leads. Each of the indicator units comprises electrically
conducting anode segments 51, 52 and 53, as well as an associated
plurality of cathode elements 61 to 68. At the same time, a
plurality of selecting leads 71 to 78 are formed on the insulating
layer 20 with the leads 71 to 74 extending along the top of the
indicator units 40 to 45 as shown in FIG. 4 and the selecting leads
75 to 78 extending along the bottom of the indicator units 40 to 45
as shown in FIG. 4. The anode and cathode segments and selecting
leads are formed by suitable thin film techniques and are formed so
as to align with the windows 30a to 38a and 30b to 30b so that
electrical connections will be made between the selecting leads 71
to 78 and the anode and cathode segments. The composition of the
anode and cathode segments will hereinafter be described in
connection with Figures.
A plurality of external leads 81 to 84 are formed on the insulating
plate 2 adjacent the lower edge relative to FIG. 4, and are
respectively connected to the selecting leads 71 to 74. A plurality
of external leads 91 to 94 are respectively connected to the
selecting leads 75 to 78 and are formed on the insulating plate 2
along the bottom edge as shown in FIG. 4.
It is to be realized that the indicator units 40 to 45, the
selecting leads 71 to 78 and the external leads 81 to 84 and 91 to
94 are formed at the same time by a silk screen process and when
the indicator units 40 to 45 and selecting leads 71 to 78 are
printed on the insulating layer 20, each of the elements 61 to 68
and 51 to 53 are respectively connected to the associated selecting
leads through the windows 30a to 38d formed in the insulating layer
20. For example, the cathode element 62 is formed so that it aligns
with window 21b which connects it to one end of the interconnecting
lead 11 and the selecting lead 74 is formed over the window 31a so
that the selecting lead 74 is connected to the cathode segment 62
through the interconnecting lead 11. Simultaneously, all of the
corresponding cathode segments 62 of all of the indicator units 40
to 45 are connected to lead 74 through associated windows and thus
all of the segments 62 of all of the indicator units are
electrically connected together and to the external lead 84.
Similarly, all of the cathode segments 61 are connected by
interconnecting lead 10 to selecting lead 72 and to external lead
82. All of the cathode segments 63 are connected by interconnecting
leads 13 to selecting lead 73 which is connected to external lead
83. Each of the cathode segments 64 is connected by interconnecting
lead 12 to selecting lead 71 which is connected to external lead
81. Each of the cathode segments 65 is connected by interconnecting
lead 15 to selecting lead 75 and to external lead 91. Each of the
cathode segments 66 is connected by interconnecting lead 16 to
selecting lead 76 which is connected to external lead 92. Each of
the cathode segments 67 is connected by interconnecting lead 17 to
selecting lead 77 which is connected to external lead 93. Each of
the cathode segments 68 is connected by interconnecting lead 18 to
selecting lead 78 which is connected to the external lead 94.
Thus, in the structure defined thus far, the associated cathode
segments of all of the indicator units 40 to 45 are electrically
connected together and thus can be electrically energized by the
eight cathode selecting leads 81 to 84 and 91 to 94. The three
anode segments 51, 52 and 53 of each of the indicator units 40 to
45 are interconnected together by the interconnecting lead 14 and a
separate external lead is formed along the lower edge of the
insulating plate 2 so that the anode segments of each of the
indicator units can be individually energized. For example, an
external lead 110 is connected to interconnecting lead 14 of the
indicator unit 40 which is connected to the anode segments 51, 52
and 53 of the indicator unit 40 and the indicator unit 40 will be
energized when the external lead 110 is energized with a selective
pattern of the cathode segments.
Likewise, the anode segments of the indicator unit 41 are connected
through an interconnecting lead to the external anode lead 111 for
the indicator unit 41. An external lead 112 is connected to the
associated anode segments of the indicator unit 42 in a similar
manner. An external lead 113 is connected to the anode segments of
the indicator unit 43 and an external lead 114 is connected to the
anode segments of the indicator unit 44. An external lead 115 is
connected to the anode segments of the indicator unit 45.
The indicator display tube is adapted to prevent an incorrect
message display which is caused by accidental discharge of the
indicator units. For this purpose in the illustrated example an
auxiliary electrode or barrier segment designated at 100 is
utilized. The barrier electrode 100 may be formed around the
indicator units 40 to 45 on the insulating layer 20 at the same
time as the indicator units and leads and has suitable windows for
the indicator units as shown. A lead 101 is also formed on the
insulating layer 20 and extends from the barrier electrode 100 to
an external lead 102 so that a suitable voltage may be applied. The
leads 101 and 102 are formed at the same time that the barrier
electrode 100 is formed. The leads, cathode and anode segments and
barrier segments are all formed of silver paste coated with nickel
which adheres well to the glass insulating layer 20.
As shown in FIG. 5, a second insulating layer 120 of glass is
deposited over the selecting leads 71 to 78 and 101 but the
indicator units are left uncovered by this second insulating layer
120. In other words, the cathode segments 61 to 68 and the anode
segments 51 to 53 of each of the indicator units are left uncovered
by the second insulating layer 120. The external leads are also
left uncovered by the second insulating layer 120.
After the indicator units are formed on the base plate 2, the cover
plate 3 is attached to the base plate 2 as shown in FIG. 6 by
suitable cement or other means so as to form a sealed chamber
between the base plate 2 and cover plate 3 which encloses the
indicator units. The external leads have portions which extend
beyond the cover plate 3 on the base plate 2 so that electrical
connection can be made.
The anode and cathode segments of the indicator display tube of
this invention are formed by plating nickel on silver paste coated
on the glass base plate because silver paste has a low firing
temperature and adheres well to the glass base plate. In general,
however, silver sputters easily in an atmosphere of a neon, argon
or like gas within a discharge tube and for this reason, nickel
which does not sputter easily is plated on the silver paste to
prevent sputtering.
FIG. 7 is an enlarged fragmentary cross-sectional view of the
indicator unit shown in FIG. 5. It can be noted in this figure that
nickel has not been deposited in sufficient thickness on the edges
260 of the silver paste layer 61 and there is the possibility that
the silver will sputter and cause an incorrect message display or
shorten the service life of the indicator display tube.
FIG. 8 schematically illustrates in section one portion of an
improved indicator unit which avoids the defect caused by the edges
of the silver paste not being covered. In the illustrated example
an interconnecting lead 300 connected to a selecting lead is formed
of silver paste on the glass base plate 2 and an insulating glass
layer 20 of a low melting point is formed on the base plate 2 over
the interconnecting lead 300. A window 30a is formed in the glass
layer 20 at a location corresponding to one portion of the
interconnecting lead 300.
Then, nickel is electro-plated in the window 30a of the glass layer
20 to form a nickel plated layer 301 therein.
Then a nickel layer 302 about one micron thick is formed by
non-electrolytic plating over the entire area of the insulating
glass layer 20 including the nickel plated layer 301 and then a
nickel layer 303 about 5 to 10 microns in thickness is formed by
electroplating over the nickel layer 302.
Then an etching mask layer (not shown) of the same pattern as that
of the electrodes to be ultimately formed is deposited on the
uppermost nickel layer 303 and the nickel layers 302 and 303 are
selectively etched away through the etching mask layer. Thereafter,
the etching mask layer is removed. In this manner, electrode
segments of a desired pattern are formed on nickel on the glass
layer 20 to provide a desired indicator unit.
Thus, the cathode and anode segments are all formed of nickel, and
hence will resist sputtering and will withstand long usage. Also,
the lead 300 connected to the electrode segment is formed of silver
paste which adheres well to the glass base plate 2 and the
mechanical bonding of the electrodes is excellent.
FIG. 9 illustrates another modification of this invention in which
an interconnecting lead 310 is formed of silver paste on the glass
base plate 2 and an insulating glass layer 20 is formed on the
interconnecting lead 310 with one portion of the latter left
uncovered to form a window 30a. Then, silver paste of the same
pattern as an electrode to be ultimately formed is printed by
printing techniques on the glass layer 20 including the window 30a
and is baked to form a sub-structure layer 311 constituting one
portion of the electrode segment. The layer 311 and the
interconnecting lead 310 are both formed of the same silver paste
and they will be firmly joined together mechanically through the
window 30a in the glass layer 20.
Thereafter, the layer 311 is plated with a copper layer 312, which
is then plated with a nickel layer 313. The entire structure is
heated to a range of about 350.degree. to 430.degree.C. in an
oxidizing atmosphere to oxidize the edge portion 260 of the copper
layer 312 to which the nickel plated layer 313 has difficulty in
adhering and a copper oxide layer 315 such as Cu.sub.2 O, CuO will
be formed to form the desired electrode.
With such an arrangement, the upper surfaces of the silver paste
layer constituting the cathode or anode segment are covered by the
nickel layer 313 over the copper layer 312 and the peripheral edge
portion 260 is covered by the copper oxide layer 315, so that
sputtering of the silver paste will be completely prevented.
FIG. 10 shows a further modification of the invention in which an
interconnecting lead 320 is formed of silver paste on the glass
base plate 2 and an insulating glass layer 20 is formed over the
base 2 and has a window 30a to expose one portion of the
interconnecting lead 320. Then, a platinum paste layer 321 of a
predetermined pattern is printed by printing techniques on the
insulating glass layer 20 and over the window 30a and the entire
structure is baked. A nickel layer 322 is then plated onto the
platinum paste layer 321 to provide desired cathode and anode
segments.
The platinum paste has a baking temperature of about 560.degree.C.
and adheres well to glass.
With the above arrangement, the sub-structures of the cathode and
anode segments are formed of platinum which does not sputter and
the electrode segments will have long life.
Furthermore, in order to prevent oxidation of the surface of anode
segments, a precious metal, for example, platinum or gold, may be
used for anode segments. For this purpose, the cathode segments may
be formed by plating nickel on silver paste as described above.
It will be apparent that many modifications and variations may be
effected without departing from the spirit and scope of the novel
concepts of this invention.
* * * * *