US3564324A

US3564324A - Gas discharge tube comprising a number of electrodes united to form a group and having the form of characters

Info

Publication number: US3564324A
Application number: US776471A
Authority: US
Inventors: Adrianus Anthonius Ma Hendriks
Original assignee: US Philips Corp
Current assignee: US Philips Corp
Priority date: 1967-12-05
Filing date: 1968-11-18
Publication date: 1971-02-16
Anticipated expiration: 1988-02-16
Also published as: NL6716506A; GB1182050A; FR1599121A; DE1809090A1; AT284974B; ES361029A1; CH489112A; BE724856A

Abstract

The digit-electrodes of a number of character-shaped electrodes of electrode groups placed side by side in a common envelope are shaped as punched strips, stacked one on the other.

Description

United States Patent Inventor Adrianus Anthonius Maria Hendriks Emmasingel, Eindhoven, Netherlands App]. No. 776,471 Filed Nov. 18, 1968 Patented Feb. 16, 1971 Assignee U.S. Philips Corporation New York, N.Y. Priority Dec. 6, 1967 Netherlands 6716506 GAS DISCHARGE TUBE COMPRISING A NUMBER OF ELECTRODES UNITED TO FORM A GROUP AND HAVING THE FORM OF CHARACTERS 4 Claims, 11 Drawing Figs.

U.S. Cl 313/l09.5, 313/210 Int. Cl. H0lj 61/66, HOlk 7.04

[50] Field olSearch 313/1095, 108, 210; 315/169 [56] References Cited UNITED STATES PATENTS 2,520,513 8/1950 Sereno 313/109.5X 3,361,920 1/1968 Rosenfeld 1. 313/1095 3,418,509 12/1968 Frouws et a1. 313/1095 Primary Examiner Roy Lake Assistant ExaminerDavid OReilly AnomeyFrank R. Trifari ABSTRACT: The digit-electrodes of a number of charactershaped electrodes of electrode groups placed side by side in a common envelope are shaped as punched strips, stacked one on the other.

PATENTEU Fan Si n 3564;324- susnlur's PIC-5.3a

FIGAa m 5 mm R D NN E H A s U N M R D A BY M /Q AGE .PAIENTEU-FE'BI-EIHYI sum 3 [1F 3 Flew v INVENTOR. ADRIANUS A.M.HENDRIKS GAS DISCHARGE TUBE COMPRISING A NUMBER OF ELECTRODES UNITED TO FORM A GROUP AND HAVING THE FORM OF CHARACTERS The invention relates to a gas discharge tube comprising a number of electrodes united to form a group by stacking, having the form of legible characters and arranged opposite to an anode.

In known tubes employing electrodes which are formed as legible characters and are united to form a group with the interposition of insulating plates, a group with the associated remaining electrodes is always arranged in a separate envelope. For reproducing numbers or words a number of such tubes are arranged beside and/or above each other.

The drawback is that a large number of separate tubes have to be provided so that the mutual distance of the characters represented by the tubes is comparatively large which hampers the reading. Moreover the 'use of a number of separate tubes is expensive. v

The above-mentined drawbacks are strongly reduced by using a similar gas discharge tube which, according to the invention, comprises a number of uniform electrode groups which are arranged beside each other in a common envelope, the corresponding electrodes of all the groups lying in one plane and the corresponding characters of all the groups being at the same time connected together to form a strip, the electrodes located in different planes being stacked one on the other with the interposition of correspondingly shaped strips of insulating material.

Theassembly is inserted in one envelope having an elongated cross section, which envelope may be provided on either end with pinches through which the current supply wires for the various electrodes extend in a vacuum-tight manner.

The invention will now be described with reference to the accompanying drawing, in which:

FIG, 1 shows a perspective view of a tube according to the invention,

FIGS. 2, 3, 4, 5, 6, 7 and 8 show components of the electrode system of the tube,

FIG. 9 is a partial longitudinal cross'sectional view of a tube according to the invention, and

FIG. 10 is a longitudinal cross-sectional view of another embodiment, and

FIG. 11 is a plan view of FIG. 10, partly broken away.

Referring now to FIG. 1, reference numeral 1 denotes the glass envelope of the tube which has an elongated cross section and is closed at its end by

pinches

2 and 3. The supply conductors for an auxiliary electrode and for the strips to which the character-shaped electrodes are connected extend, for example, through the pinch 2, while the current conductors for the anodes associated with the various groups extend through the pinch 3.

The set of electrodes arranged in the envelope 1, is obtained by stacking the components as follows:

On an insulating strip 4 (FIG. 2) consisting of mica artificial mica or ceramic material, a narrow strip 5 is laid (FIG. 3) which in this case comprises l lugs 6 which are bent at right angles so that the lugs 6 project upwards. On this assembly an insulating strip 7 is laid (FIG. 4) in which apertures 8 are provided through which the lugs 6 extend. Anode plates 9, in this case II), are secured to the strip 7 in such manner that they are insulated from each other, and are each provided with a current supply wire 13. The anode plates 9 comprise an aperture corresponding to the apertures 8 so that the lugs 6 projects through the anode plates 9 in an insulated manner. In fact, the lugs 6 serve as decimal points.

On the strip 7 with the anodes 9, an insulating strip 14 (FIG. is placed in which apertures 15 are provided which correspond to the anodes 9 and are separated from each other by transverse strips 15.

The characterlike electrodes are in this case shaped as digits 0-9. Figure 6 shows a strip 16 of the digits, in which the digits 0 are punched in such a manner that said digits are still connected to the strip 16 with narrow strips 17. The strip 16 comprises in this case l0 electrodes 0, which are separated by transverse strips 18. On the strip 16 again a strip 14 is provided on which a strip 16 having digits I is laid, and so on, alternately strips 14 and digit strips 16 with the remaining digits 29. As shown in FIG. 7, the strips 18 are forced through alternately to one and to the other side. As a result of this, gapshaped spaces are formed between the insulating strips 14 and the digit strips 16 so that metal sputtering from the electrodes cannot cause shortcurcuit between the digit strips 16.

A gauze electrode 19 is provided on the uppermost perforated insulating strip 14 and is also provided with a current supply conductor (12 in FIG. 1) and serves to check blackening of the tube by sputtering metal. After a mercury holder 20 is secured to the gauze 19 the set thus obtained by stacking strips and digit strips is slid into a glass tube 1 (FIG. 9) having an elongate cross section, after which the tube 1 is heated at the ends and sealed by means of a

pinch

2, 3. The tube is provided, for example, on its rear side, with an exhaust tube (not shown). After evacuating and filling with a suitable gas the tube is sealed.

The tube shown partly in cross section in FIG. 9 can reproduce a number of IO digits.

The lighting up of a digit is obtained by setting up zero potential at the digit strip in question and a positive potential of, for example volts, at the associated anode. In order to cause several digits to light up they are intermittently caused to light up with a sufficiently high frequency, so as to give a permanent lighting-up impression. The digit strips which do not light up and the gauze 19 are kept at an intermediate potential of, for example, 65 volts. In this case the gauze 19 cannot be connected to the anode 9 as in known digit tubes, since these anodes have to remain independent of each other.

FIGS. 10 and 11 show another embodiment in which the anodes 23 are in the form of a U, so that the

transverse strips

15 and 18, respectively, of the mica strips 14, and the digit strips 16 may be omitted which simplifies the manufacture and assembling. Since the'digit strips 22 are kept at some distance from each other, by the insulating strips 21, short circuit of the digit strips by metal deposits is avoided as such without forced-through strips as shown in FIG. 7 being necessary. The upright edges of the anodes 23 are kept separated by insulating plates 24. Since equal digits need not be mounted separately but can be cut as as a punched strip of a given length and be stacked, the manufacture of such a digit tube which thus contains totally I00 digits, is much simpler and cheaper than of 10 separate tubes having each 10 digits in which the decimal point usually is also formed as a separate tube. An advantage of a tube according to the invention is furthermore that the decimal point can be placed between the digits. Although a tube has been described of 10 digits located beside each other, this number may be arbitrarily chosen. Alternatively, the electrodes may be formed as letters instead of digits, while a number of the described tubes may be arranged above each other. The characters are close together since no partition walls are necessary as is the case when separate tubes are placed side by side.

Iclaim:

1. A gas discharge tube comprising an elongated envelope, a plurality of stacks of character-shaped electrodes united to form a group and positioned opposite to an anode, said electrode stacks being arranged beside each other in said envelope with corresponding electrodes of all the groups lying in one plane and the corresponding electrodes of all the groups being at the same time connected together in the form of a strip, the electrodes located in different planes being stacked one on the other with the interposition of correspondingly shaped strips of insulating material.

2. A gas discharge tube as claimed in claim 1, wherein the anodes of the stacks are arranged so as to be insulated from each other and are each provided with'a current supply conductor.

3. A gas discharge tube as claimed in claim 1 wherein the anodes have the form of a U, the upright edges constituting the'separation between the said several electrode stacks.

said electrodes light up, and means to apply to the remaining electrodes an intermediate positive potential whereby said latter electrodes do not light up.

Claims

2. A gas discharge tube as claimed in claim 1, wherein the anodes of the stacks are arranged so as to be insulated from each other and are each provided with a current supply conductor.

3. A gas discharge tube as claimed in claim 1 wherein the anodes have the form of a U, the upright edges constituting the separation between the said several electrode stacks.

4. A circuit arrangement for operating a gas discharge tube as claimed in claim 1, including means to intermittently apply zero potential and a positive potential, respectively, electrodes in each group relative to the anode for said group whereby said electrodes light up, and means to apply to the remaining electrodes an intermediate positive potential whereby said latter electrodes do not light up.