US 3581138 A
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United States Patent Inventor Adrianus Anthonius Maria Hendriks Emmasingel, Eindhoven, Netherlands Appl. No. 789,773 Filed Jan. 8, 1969 Patented May 25, I971 Assignee ILS. Philips Corporation New York, N.Y. Priority Jan. 12, 1968 Netherlands 6,800 473 GAS DISCHARGE TUBE WITH COLD CATHODE SUITABLE FOR THE SIMULTANEOUS REPRODUCTION OF TWO LEGIBLE CHARACTERS 2 Claims, 8 Drawing Figs.
U.S. Cl 313/1095 Int. Cl H01j 61/66 Field ofSearch 313/1095  References Cited UNITED STATES PATENTS 3,248,589 4/1966 Despris 313/1095 FOREIGN PATENTS 779,997 3/1968 Canada BIB/109.5
Primary Examiner-Robert Segal Attorney-Frank R. Trifari ABSTRACT: A gas discharge tube for reproducing two independently switchable legible characters which adjoin each other and constitute two groups, the characters being secured to annular frames of equal dimensions but having dimensions which are smaller than the frame and the groups being surrounded by a partially perforated anode. The two groups of characters are associated with a single electrode set. Since the characters are smaller than the associated frame, two characters associated with different groups can be reproduced.
PATENTED wzsmn 3581; 138
SHEET 1 UP 2 fig] H2 fig.3
r 2 V? g 11 ,-/s 12 u U 2 fig.4 fig.5
INVENTOR. ADRIANUS A.M.HENDRIKS AGENT PATENTEU M2519?! 3581; 138
SHEET 2 0F 2 f i i I :IAT'IB l g j 17 T i I 1 i i 1 fig-8 uuuuuuuuuu INVENTOR.
ADRIANUS AMHENDRIKS BY 2 M f -W AGENT GAS DISCHARGE TUBE WITH COLD CATIIODE SUITABLE FOR THE SIMULTANEOUS REPRODUCTION OF TWO LEGIBLE CHARACTERS The present invention relates to a gas discharge tube with a cold cathode, particularly a tube for the simultaneous reproduction of two adjacent, independently switchable legible characters.
Such discharge tubes are known but the characters which are located above or beside each other constituted two grouped which were associated with separate electrode sets. Each of the characters was secured in an annular frame which had approximately the same size as the character secured therein, so that in the area of each frame only one character could be reproduced.
However, such tubes are expensive since each group of characters has to be mounted separately before the groups are secured in a common boxlike anode which is at least partly gauzelike.
This drawback is avoided if in such a gas discharge tube, according to the invention, the two groups of characters are associated with one single electrode set, while the dimensions of the characters are so much smaller than those of the associated frame that within a surface area of a frame two characters associated with different groups can be reproduced. The frames preferably have an elongated rectangular shape in which the characters of one group are secured near one short side, those of the other group being secured near the oppositely located short side of the rectangle of the associated frame. If the groups of characters have to be located above each other, the frames are placed vertically with their long sides. The long sides of the frames will generally be placed parallel to the longitudinal axis of the discharge tube.
In order that the invention may e readily carried into effect, certain embodiments thereof will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which FIGS. 1, 2, 3 and 4 show frames with letter characters and FIG. 5 shows an insulating member of a given embodiment of the invention.
FIGS. 6 and 7 show another embodiment of the invention,
FIG. 8 shows a gas discharge tube of the embodiment shown in FIGS. 1 to 5.
Referring now to FIG. 1, reference numeral 1 denotes a metal frame which is in this case has a substantially elongated shape. However, the frame may alternatively be, for example, in the form of a circle. The frame 1 comprises apertures 2 to enable the threading on an insulated pin. On the upper short side of the frame 1, a character in the form of the letter M is secured. The height of the character is slightly smaller than half of the height of the frame 1.
As shown in FIG. 2, the letter V, referred to by reference numeral 4, is secured in the same manner to the lowest short side of the frame 5, so that within the surface area of the frame two characters can be reproduced which are associated with different groups.
In FIG. 3, the letter A, reference numeral 9, is secured to the lower side of the frame 10 and the letter K in FIG. 4, reference numeral 11, is secured to the upper side of the frame I2.
The frames 1, 5, l0 and 12 are threaded on pins 15 which are covered with insulating material, separated by insulating plates 6 as shown in FIG. 5. Finally the set obtained is placed in a boxlike anode 16 which consists partly of a wire gauze 17. The tube as shown in FIG. 8 can represent above each other, the letters MV, MA, KV or KA. by providing the characters in the frames while rotated through said characters can also be represented beside each other. The uppermost group will generally furthermore comprise the characters m, n and p and the lower group also the characters 0, F, H and S.
In order to avoid the threading, the frames 1, 5, l0 and 12 and the insulating plates 6 may be stacked in a U-shaped anode-part 7 as shown in FIGS. 6 and 7 and, by providing a cover 13 which is capable of sliding, in the art 7 they may be secured therein by clamping FIG 6 an 7). The cover 13 may be secured to the side walls of the anode part 7 by welding. The cover 13 is provided with an aperture which is covered by wire gauze 14.
In order to avoid shortcircuits between anode 7 and the frames of the characters, insulating strips oran insulating layer 8 are provided against the sidewalls of the U-shaped anode 7. However, the anode may alternatively be manufactured from aluminum or an alloy hereof and said sidewalls may be covered with an insulating aluminum-oxide layer by electrolytic oxidation.
It is obvious that instead of the characters shown the characters may be constituted by an other symbol. For example, the characters and the associated frames may form one assembly an be punched or etched form a plate but alternatively they may consist of wire and be welded to the associated frame or be obtained by metal deposition.
1. A gas discharge tube for reproducing two independently switchable legible characters which adjoin each other and constitute two groups, the characters each being secured to separate annular frames each of which have the same dimensions and given surface area, the groups being surrounded by an anode gauze between said groups and the viewing wall of said table, comprising the two groups of characters being associated with one single electrode set, each character having dimensions smaller than those of the frame to which it is secured all of said frames being stacked on a pair of insulated pins with adjacent character-supporting frames separated by insulating platelike frames, the characters in adjacent frames being supported at opposite sides of said adjacent frames in nonoverlapping relationship whereby two characters associated with different groups can be reproduced within said surface area.
2. A gas discharge tube as claimed in Claim 1, wherein each frame has the form of an elongated rectangle and supports one character which is secured at one side having the shorter dimension.
PO-ww UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,581,138 Dated May 25, 1971 Inventor(s) ADRIANUS A. M. HENDRICKS It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 2, line 13, "m, n and p" should be m ,=,n and p. line 24, "oran" should be --or an-.
line 33, "form should be -from-.
line 43, "table" should be --tube-.
Signed and sealed this 8th day of February 1972.
EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents