US1834072A

US1834072A - Glow lamp

Info

Publication number: US1834072A
Application number: US373744A
Authority: US
Inventors: Schroter Fritz
Original assignee: Telefunken AG
Current assignee: Telefunken AG
Priority date: 1928-07-04
Filing date: 1929-06-26
Publication date: 1931-12-01
Anticipated expiration: 1948-12-01

Description

USC. i931. F SCHRTER 1,834,072

GLOW LAMP Filed June 26. 1929 Illllllllll INVENTQR rmz SCHROTER BY WM ATTORNEY Patented* Dec. 1, 1931 UNITED STATES PATENT?` OFFICE FRITZ SCHRTIB, 0F BERLIN', GERMANY, ASSIGNOB T0 TELEFUNKEN' GESELLSCHAFT FR IDRAHTLOSE TELF-RAIPHIE I. B. H., 0F BERLIN', GEBIANY, A CORPORATION OF GERMANY Grow LAMP Application filed .Tune 26, 1929, Seriallo. 873,744, and in Germanyluly '4, 1928.

' The present invention relates to glowdischarge lamps as adapted to the photographic or visible recording of current variations, particularly for the purposes of optical telegraphy, picture telegraphy, television, producing sound records on moving picture films, and similar purposes. It is useful both in connection with glow-discharge lamps operating with a relatively cold cathode and a correspondingly high cathode fall as we ll as with lamps wherein the cathode fall'ls diminished by the use of thermal emission, as in glow-discharge lamps furnished with a heated cathode.

According to the prior art, glow-discharge lamps of this kind were equipped witha'n anode and a cathode, but the A. C. passing therethrough was used onlyin one direction, irrespective of whether the cathode glow or the positive luminous column served as the electrically controlled light source.

The invention has been illustrated by the accompanying drawings, wherein: l Fig. 1 shows one of the circuit arrangements adapted to this purpose and to the operation of such lamps, the latter being operated mostly in connection with an amplifier; Y

Fig. 2 shows a preferred form of glow lamp construction; and,

Fig. 3 shows a circuit arrangement for util lizing the lamp shown by Fig. 2.

Now, referring to Fig. 1 of the drawings, the glow-discharge lamp 1 is inserted in the circuit of a D. C. source, say, a battery 2, the current being adjusted to a definite value by .the aid of resistance 3. By means of transformer 4, the D. C. potential derived from 2 has superposed thereon acontrolling A. C.

potential whose amplitude and frequency is` indicated or recorded by the light variations. Transformer 4f, for instance, is contained in the plate circuit of the last tube of anamplifier which amplifles telegraphically received picture signals. Inasmuch as a D. C. potential exists between the electrodes ofthe glow lamp 1 upon which the controlling" A. C. potential of 4 having comparatively low amplitude is su erposed, it will be seen that one half wave o the A. C. potential which is of v A. C. potential will counteract the D. C. po-

tential so that the discharge current and the luminous intensity of the lamp are correspondingly diminished. Inasmuch as the value of the current which flows in 4 when the A. C. potential is of zero value is usually,

set to such low amounts that it is not capable of producing practically any photographic action upon the film or not lcapable of resulting in a luminous impression or perception in television, it will be seen that the second half of the wave of A. C. potential, since it undergoes a reduction both in the value of the current and luminous radiation, is lost so far as the recording or visual impression is concerned. Another aggravating fact present under certain circumstances is that the potential diiierence or minimum vcurrent required for maintaining the discharge is not attained, with the result that the circuit may be broken, and that the operation of the outfit becomes unstable.

Now, according to the present invention, a glow-dischargelamp of the kind before described, as shown in Fig. 2, is furnished with three electrodes, that is to say, either with two distinct anodes and a joint cathode, or else with two cathodes and a common anode. Which form of construction should preferably be chosen depends upon whether it is the negative glow layer at the cathode that is used as the luminous source, or whether other parts of the discharge, such as the 'positive column is employed.- In what follows, a

- lamp is described by reference to Fig. 2 with a cold cathode and the utilization of a primary or secondary cathode' .glow la er.

sired, bein sealed by fusion in separate tubular appendages 7 and 8. The shape of such anodes and seals does not fall inside the scope of this invention, and this holds true also of constructional details, the provision of distinct diaphragms, screens, or the like, as used in connection with the different uses and applications of the lamp. When the discharge passes through the gas filling which, for lnstance, in the case of -photography consists of a markedly actinic mixture of argon and nitrogen, or in the case of television of a mixture of neon and helium exhibiting great brightness inside the visible spectral range, the interior of cathode 5 is filled with a glow light, while at the constricted outlet opening thereof, a secondaryy glow light of great intensity is produced which is radiated off across a window 11 made from glass, quartz, or other transparent material cemented thereon.

The arrangement hereinbefore described is capable of a great number of modifications as regards the nature of the cathode and the utilized portion of the discharge, especially in cases where a common anode and two distinct cathodes are employed.

Now, a lamp of this kind allows of the utilization of both halves of the controlling A. C., and it thus insures a higher eiiciency; in other words, at the same amplifier power double photographic blackening or double luminosity.

A circuit arrangement useful for operating the scheme is shown by way of example in Fig. 3, though the same is capable of various modifications. The D. C. potential source 2 is again connected in series with a resistance 3- and' cathode 5, opposite which there are mounted the two anodes' 9 and 10,

similarly as in Fig, 2,-'the latter being united with the two ends of the secondary winding of a transformer 12 to the middle of which the other pole of the D. C. source 2 is connected. 'I'he primary winding of 12 is again connected in the output circuit of an amplifier. As will be readily understood, the two half-waves of the controlling A. C. potential are so superimposed upon the discharge D. C. that an amplified or intensified current passes over to the cathode 5 alternately from the anode 9 and from the anode 10. As a result, both half-waves cause an intensified luminosity.

Other changes and modifications will at once suggest themselves to those skilled in the art to which the invention relates. and I, therefore. believe myself to be entitled to make and use all modifications of this invention such as fall fairly within the spirit and scope of the hereinafter appended claims. lI aving now described my invention, I c aim 1. In a glow lamp construction, a cathode .5 member, a plurality of anode members cooperating with said cathode member and spaced apart therefrom, and a tubular memr surrounding said cathode member and extending outwardly therefrom toward said anode members.

2. A glow lamp construction adapted to produce luminous rays from both halves of supplied alternating currents com rising a pair of anode members arranged su stantially adjacent each other, a cathode member remotely spaced and equi-distant from each of said anode members, and a tubular insulating member surrounding said cathode and extending for substantially the distance separating the said anode members from said cathode members for shielding said cathode member and confining the glow produced within said lamp to a predetermined area.

3. In a glow lamp construction, a cathode member, a tubular insulating member surrounding said cathode member and extending outwardly therefrom, said tubular member being open at the end thereof remote from said cathode. a pair of anode members separated from said cathode member and arranged adjacent the open end of said tubular member opposite said cathode, and an enclosing envelope surrounding all of said electrodes.

4. In a glow lamp construction, a cathode member, a tubular insulating member surrounding said cathode member and extending outwardly therefrom, a pair of anode members separated fromsaid cathode member and arranged at the end of said tubular member opposite said cathode, and an enclosing envelope surrounding all of said electrodes.

FRITZ SCHRTER.