US2594357A - Electronic animated advertising sign system - Google Patents

Description

April 29, 1952 R. H. SEAMAN 2,594,357

ELECTRONIC ANIMATED ADVERTISING SIGN SYSTEM Filed March 3, 1947 4 Sheets-Sheet l W??? J i Elli? I N VEN TOR.

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ATTORNEY April 29, 1952 R. H. SEAMAN 2,594,357

' ELECTRONIC ANIMATED ADVERTISING SIGN SYSTEM Filed March 5, 1947 4 Sheets-Sheet 2 IN V EN TOR.

: ATTOR/VE'Y 1 April 29, 1952 R. H. SEAMAN ELECTRONIC ANIMATED ADVERTISING SIGN SYSTEM Filed March 3, 1947 4 Sheets-Sheet 3 INVENTOR- WW BY ATTORNEY aidaw 45E. 5m

April 29, 1952 R. H. SEAMAN 2,594,357

' ELECTRONIC ANIMATED ADVERTISING SIGN SYSTEM Filed March 3, 1947 4 Sheets-Sheet 4 -IIG 11 IN VEN TOR.

- w Jae; In}. 1 3 By W Patented Apr. 29, 1952 ELECTRONIC ANIMATED ADVERTISING SIGN SYSTEM Richard H. Seaman, Los Angelcs, Calif asslgnor to Mega Corporation, Los Angeles, Calif a corporation of California Application March 3, 1947, Serial No. 731,894;

8 Claims. (Cl. 177-346) My invention relates broadly to advertising signs and more particularly to a method for operating an electronic animated advertising sign and a construction of an electronic animated advertising sign.

One of the objects of my invention is to provide a method of operating an electronic advertising sign for producing animated and mobile patterns in repeated succession.

Another object of my invention is to provide a method of exciting electron discharge tubes by rectified current pulses in such manner that emission of light rays is effected for producing fluorescence.

Another object of my invention is to provide a construction of electronic animated advertising sign system employing a multiplicity of fluorescent tubes of the hot cathode type with means for controlling the fluorescence in such tubes according to a predetermined. pattern.

- Still another object of my invention is to provide an electronic animated sign system employing a multiplicity of fluorescent tubes of the hot cathode type each including a plurality of sequentially spaced anodes including a source of unfiltered rectified current pulses adapted to be impressed upon the sequentially spaced anodes with means for sustaining fluorescence throughout one of said tubes while progressively building up fluorescence in the other of said tubes.

Still another object of my invention is to provide an arrangement of multiple fluorescent tubes of the hot cathode type, each employing a plurality of sequentially spaced anodes including means for successively electronically exciting the sequentially spaced anodes according to a predetermined pattern and periodically deenergizing all of said anodes for producing spaced animations or displays by the tubes.

A still further object of my invention is to provide an improved structural arrangement of anode and mounting system for hot cathode fluorescent tubes as set forth more fully in the specification hereinafter following by reference to the accompanying drawings, in which:

Figural is a diagrammatic illustration of an electronic animated advertising sign system embodying my invention; Fig. 2 illustrates a modifled arrangement of the electronic animated ad vertising sign system of my invention; Fig. 3 illutrates one method of arranging the coacting hot cathode tubes in a preformed pattern in carrying out the system of my invention; Fig. 4 is an elevational view showing the manner of mounting one of the tube sections in the arrangement illustrated in Fig. 3; Fig. 5 is an enlarged elevational View of a fragmentary portion of the tubes constituting the pattern illustrated in Fig. 3, portion-s of the tubes being broken away and illustrated in cross section to more fully i1;

lustrate the coacting relation of the adjacent tube sections; Fig. 6 is a top plan view of tube sec-1 tions illustrated in Fig. 5'; Figs. 7-10 illustrate progressive steps in the manufacturing process in the production of tubes according to the systemof my invention, wherein Fig. '7 illustrates the manner of starting the installation of one of the anodes in the tube of my invention; Fig. 8 illustrates the manner of perforating the side wall of. the tube for mounting the anodes within the tube; Fig. 9 illustrates the manner of supporting an anode within the tube; Fig. 10 is a, horizontal sectional view taken on line Ill-Hi of Fig. 9; Fig. 11 is an enlarged plan view of one oi the anodes employed in the tube system of my inventicn; Fig. 12 is a side elevational view of the anode shown in Fig. 11; Fig. 13 illustrates the characteristic curvesof the coacting full wave rectifiers which supply unidirectional current pulses to the electronic stream within the tube system of my invention; Fig. 14 is a curve: illustrating the building up and decaying of the electron emitting condition in the electronic stream within the hot cathode tube employed in the advertising sign of my invention; and Fig. 15 is a curve diagram '11- lustrating the effective portion of the current pulses supplied to the electron stream within the tube which is relied upon for eifecting the emission of light rays for producing fluorescence.

My invention is directed to that class of advertising signs which employs heated cathode electronic tubes utilizing a multiplicity of spaced anodes to which electronic discharge may be sequentially andselectively directed by virtue of selective energization of the separate anodes in predetermined order and according to a PIE-.- formed pattern at a rate greater than the persistence of vision to give the effect of gradual flowing of the illumination. The electronic tubes employed are of low voltage type comprising a gas pressure of the order of 2- m-illimeters or less. using any desired rare gas such as argon with a small quantity of mercury. Any combination of gases may be employed depending upon the spectral sensitivity of the fluorescent material.

The electronic tubes employed in the sign are rangement of my invention are operated from the usual industrial power source of 110 volts, cycles, alternating current and have associated therewith an unfiltered full wave rectifier system for supplying successive direct current pulses to the several sequentially spaced anodes. The rectifier system employed is of the full wave, type so that each half wave portion of the rectifier produces a pulse of av rising and falling characteristic. The two half wave rectifiers coact to produce successive rising and falling pulses adjacent each other which are impressed upon the sequentially spaced anodes at a rate greater than persistence of vision. The pulses of unidirectional current cause a flow of successive stream of electrons from the heated cathode to the sequentially spaced anodes at a rapid rate which causes ionization of the gas molecules resulting in the emission of a ray at a frequency that in turn will excite the fluorescent material used in the tube. The hot cathode type of tube employed in the system of my invention produces more ultra violet light per watt input than a cold cathode type, such as neon. This produces more usable light by fluorescence per watt. Also, the hot cathode type tube will pass many times more current without heating the tubing than a neon cold cathode type of tube. The amount of fluorescent light obtained by the fluorescent tubing is proportional to the current through the tube. Therefore, the system of my invention provides many times more brilliance than the conventional neon tubing. The fluorescence is completely stopped at each complete succession of the electrical control system for the sign preparatory to a repeat operation so that proper space is provided between the fluorescent writing patterns. Special provision is made for continuing the fluorescence in one electronic tube while fluorescence is being built up or caused to flow in a coacting or adjacent electronic tube.

My invention is not to be confused with gaseous discharge tube systems that employ high frequency and high voltage for the production of gaseous discharge within the tube, nor is it to be confused with the multiple electrode low voltage self starting tubes of the conventional fluorescent type.

.Referring to the drawings in detail, and particularly to my invention as exemplified in Fig. 1, I have shown the writing sign as including two electron discharge tubes 56 and 51. The electron discharge tubes may take various shapes and have various arrangements to present desired designs and patterns in the production of a mobile electronic discharge sign. Electron discharge tube 56 contains heated cathode 58 while electron discharge tube 51 contains heated cathode 59. Heated cathode 58 is energized from a suitable transformer 95, while cathode 59 is energized from transformer 96, both of which contain midtaps which extend to the exciting circuits.

Each of the electron discharge tubes 56 and contains a multiplicity of sequentially spaced anodes represented at I, 2, 3, 4, 5 and 5, disposed in electron discharge tube 56, and sequentially spaced anodes I, 9, II], II and I2 disposed in electron discharge tube 51.

The transformers 95 and 95 which supply heating current to the electron emitting cathodes 58 and 59 for establishing the stream of electrons through each of the tubes are connected to the power source represented at terminals 91. The power source is the conventional 110 volts, 60 cycles alternating current power circuit. The power circuit 91 connects to two independent power rectifier circuits, one of which I have designated at 98, the other of which has been shown at 59. These rectifier circuits have their input transformers connected to the power source 91 and have unfiltered outputs which supply. direct current pulses to the anode circuits of the electron discharge tubes 56 and 51. I provide selective means for sequentially impressing the direct current pulses on the spaced anodes in the form of a rotatably driven switch arm (H which is operative over a multiplicity of contacts corresponding in number to the number of anodes in the electron discharge tubes 56 and 51 under control of motor 40. Motor 40 is operated from the connection 4| to the alternating current supply source under control of switch 42 which is closed to start the motor and opened to stop the motor. Switch 42 may be operated simultaneously with the master switch in the circuit leading to the power circuit from source 91. The contacts over which the switch arm 6| operates are represented at I, 2, 3', 4', 5', 6', I, 8, 9,

tacts I i to provide a longer time period over which contact is established as switch arm 6| revolves to maintain the sign illuminated for a givenv time period after the energization of all of the electrodes in predetermined sequential order has been completed.

An electrical switch operated intermediate the last contact I2 and the start contact I has been indicated at I00. Swich I60 constitutes a single pole contactor which is momentarily depressed by the sweep of switch arm 6| to open the power supply circuit to the rectifiers 98 and 99 when the writing pattern is complete. Thus, the sign is extinguished between each successive writing operation. During this time interval, however, the cathodes 58 and 59 are maintained energized and the electron emission maintained.

I provide an arrangement of relay switching means for insuring the writing continuity of the sign. This relay switching means is shown at 52. Relay actuating winding 520. controls a set of contacts 54. I have designated the output of the unfiltered rectifier 98 by reference character and the output of the unfiltered rectifier 99 by reference character 5I. The negative pole of source 50 connects to the center tap 95a of transformer 95 leading to cathode 58, while the center tap 96a of transformer 96 connects to the nega' tive terminal of source 5I. The positive side of source connects through contacts 54 with the relay winding 52a and anode 6 of the electron discharge tube 55.

As switch arm BI passes sequentially over contacts I, 2, 3, 4 and 5', the anodes I, 2, 3, 4 and 5 are successively energized from the positive source 58 which connects to the switch arm BI. The electronic discharge from cathode 58 thus flows from cathode 58 to the successive anodes in the sequence stated. When arm 6| moves to contact 6' switch winding 52a is energized clos= ing contacts 54 and impressing positive voltage on anode 6 from the positive side of source 50. Thus, the electronic stream switches from cath odes 53 to anode 6 and the entire tube 56 luminously glows. As switch arm 5| passes to contact I and the successive contacts include contact I2 the discharge from cathode 58 to anode '6 is maintained inasmuch as current from source 59 continues to pass through relay winding 52a and contacts 54. By useof stick relay 52 illumination is maintained in tube 56 while illumination is permitted to build up and flow in tube 51 for performing the writing operation.

Referring to Fig. 2 I have illustrated in detail the manner in which the glow discharge is caused to flow in a predetermined pattern in shaped tubes. For purposes of illustration I have selected the letter M as illustrative of the principles involve in the electronic discharge sign. I have shown separate tubes forming the sections of the M at 80, SI and 82. These sections are pretormed into the shape of the letter The reason for providing a multiplicity of" sections is to maintain the total applied voltage low and at asafe limit between any anode and ground. Each of the electron discharge. tubes 80', 8t and 82 contains a cathode represented at 88c, 8'lw and 82a, which are separately energized through heating transformers 80b, 81b and. 821). In lieu' of the separate transformers shown: I may pro vide a single transformer having the primary winding connected to the power source 9 1' with,

secondary windings connected to the respective cathodes of the respective tubes. Each tube 80., ill and 82 includes a multiplicity of anodes ar ranged to be electronically bombarded by elec trons from the respective cathodes in sequence and according to a predetermined pattern as ex.- plained in connection with thecircuit of Fig. l. The anodes in the several tubes have; been sequentially' designated in a manner similar to. the disclosure of Fig. 1', that is; tube 86 contains anodesi, 2, 3, l, 5', l, and 8-, while tube 81' contains anodes 9, H], H, I2, 1 3 i4, i5 and; It. Tube 8 contains anodes H, i8, i9, 20, 2|, 22', 213 and 24, the anodes being sequentially spaced to form the pattern in which the electronic discharge must flow. A- motor driven rotatable switch arm it is provided in the same manner as explained in connection with Fig. 1 and operates sequentially over successive contacts correponding in number to the number of anodes and which I have numbered I", 2", 3 4", 5', 6, I38, 3', Iii, it", I2", l2, l4, l5, l6, ll", l8., I9, 29', 2|, 2', 23, 24'. Separate sources of rectified energy are utilized in the arrangement oi Fig. 2 similar to the arrangement. of Fig. 1 as represented at 5! and 51. In the arrangement shown in Fig. 2 the number of sources has been reduced to two for the three. tube sections since tube 83 can be supplied by rectified: cur rent from source 53 and tubes 8! and.82z maybe connected in series and supplied by the second source 51. Tubes 8! and 82 are then in eiiect like one tube, but arranged in series.

I provide the same arrangement of stick magnet circuit relay 52 in the circuit of Fig. 2 as used in the circuitof Fig. 1. In this arrangement the relay actuating winding 52a is con nected in series between anode 8 and the positive power source so that as contact 8" is made and winding 52a. energized contacts 54 are closed, thereby completing the circuit to source 59 and maintaining tube. 8b in glow operation while r0.- tating: switch arm Si is moved over the succe.ed ingi contacts 9'" through 24'. As hereinbefore noted, tubes 35 and 82' are in series through lead mi: so that glow discharge is maintained through tube section 81 while switch. arm; 61' is progressiyely moving over contacts l5"24 in successive energizing anodes ll, 24, of tube section 82'. The single pole single throw switch Nit described in: connection with Fig. 1 is interposed. between the final contact 2 3' and the start contact i so thata complete extingui'shment of. the glow dischargeis eiiected after completion ofeach revolution of arm 5i. This is effected by arm 6| striking switch E03 in the course of revolution thereof for opening the power circuit from source 91 to the input circuits of each of the rectifiers 98'and d9. By properly spacing the contacts the time interval during which the excitation of the glow of the electron discharge tubes is extingui-shed may be regulated to meet particular requirements.

Incarrying out the principles of my invention I may mount a multiplicity of tubes. in var ious ways. For example, I may/provide. separate envelopes'for the tubes represented at 89, 90,81 and 92 arranged end-to-end in the form. representative of the design to be produced. The separate tubes are. so' arrangedv that collectively they present. a preformed. pattern. or design. and yet each tube includes a. multiplicity of anodes. and a coacting discharge cathode, as explained; in connection. with the circuits of Figs. 1. and. 2.. The individual tubes establish butt joints with respect to each other in forming the words, let-- ters, symbols or an animation.

Fig. 3 illustrates one method of assembling amultiplicity of electronic: tubes to. form a prede-- termined letter or pattern. Tubesi89, 90, 9| and 92, each have a portion thereof extendingsub-- stantially normal to the longitudinal. length thereof at each terminus end. Each. terminus end is provided with a flattened wall as shown for example in Fig. 4 Where. tube 9f has been illustrated as supported by frame. M formed from insulation material and having flattened ends 9m and Sit against which coacting ends of ads jacent tubes forming the continuity of. the pattern may abut. In the particularly tube illustrated I have represented the electronic discharge cathode at 93 and the sequentially spaced anodes at l', 2', 3 and 4. The butt joints for the coacting tubes have been represented in Fig. 3 at 86, 81 and 63.

In Fig. 5 I have illustrated the manner in which the cathode end of tube- 92 abuts with the anode end of tube 89 in the abutment ppsition indicated at 86 to insure continuity and now of the electronic discharge. Similarly, the anode end of tube 93 abuts, as represented at 8?, with the cathode end of tube 95. InFig. 6' I have illustrated the manner in which the terminus portions of the coacting tubes extend rearwardly from the tubes 89, 92 and Bil to enable electrical connections to be made thereto behind the flattened support 94. The method of forming the electronic discharge tubes is' one of the features of my invention.

I have shown in Figs. 7-10 the successive steps employed for mounting the multiplicity of anodes within the tube. In Fig. '7 the tube 89 is subjected to a blast of heat from torch flame I92 while the tube is closed at both endsby fork members we and IM and subjected to air pressure through blow tube I115. Thisope'ration results in the puncturing of the side wall of the. tube 89 as represented at I06 in Fig. 8. The anode consisting of the cylindrical sleeve member I61, and which is of soft iron carried by lead wire I08 having glass bead I09 thereon, is then introduced through aperture Hi6 in the side wall of the tube as represented in Fig. 9. As shown in Fig. 10 the bead IDS isthen fused into the glass Wall of tube 89 by application of further heat to the tube 89 and bead I09. When cooled the anode It? is directly supported in the electron discharge path extending longitudinally of the tube. In some of the signs which I have constructed, 1' have employed a tube containing I as many as twenty-five anodes at sequentially to clarify the nature of these anodes I mention here that the anodes are formed of soft iron tubing of approximately in diameter and of approximately in length as represented at I01 and crimped upon the lead wire H38 as represented at i 01a. When it is realized that these anodes are disposed diametrically of the glass tube represented at 89, and that the anodes areof such small dimension, it will be appreciated that large area is not required for elec tronic operation of the sign of my invention as distinguished from the relatively large electrodes heretofore employed in gaseous discharge types of advertising signs with all of their inherent difliculties of installation.

The small size electrodes inserted along the tube will pass many times more current, with" out heating, inserted straight in, as illustrated in Figs. 11 and 12, rather than longitudinally of the tube. The arrangement of my invention reduces sputtering which darkens the tube over a period of time.

In the manufacture of the tube, to remove the occluded gases in the metal, it is necessary to get all the little electrodes hot during the pumping process. By the arrangement of my invention, when bombarding the tube from both ends the little electrodes that are inserted as shown in Figs. 11 and 12 will all get hot; whereas, if the electrodes were arranged longitudinally of the tube the intermediate electrodes would take more time and current in order to raise them to a high enough temperature to de-gas them. Hence the arrangement of my invention is very advantageous in the manufacture of the tubes.

In Fig. 13 I have represented the electrical characteristics of the pulses which are supplied to the electron discharge tubes constituting the advertising sign of my invention. The input to the full wave rectiflers 98 and 99 from source 91 is represented at H0. In rectifier circuit 98 the half wave rectifier 98a furnishes to the electronic discharge advertising sign tube 56 pulses represented at H2. The pulses in the half wave rectifier section 98b are represented at H3 displaced 180 degrees with respect to the pulses H2 in the rectifier section 98a. The composite rectifier pulses supplied by the full wave rectifier source 59 are represented at H4. Thus it will be seen that, as switch 6! establishes successive contact with, contacts I, 2, 3, etc., at a rate greater than the persistence of vision, the electronic stream from cathode 53 to'the sequentially spaced anodes actually builds up and decays according to the characteristic curve H4 successively. This rising and falling characteristic produces ionization of the gases within the tube 58 resulting in fluorescence without the defects of dark spaces arising under the conventional Crooks theory. The resultant action is a brilliant fluorescence due to electronic action sustained by the successive and repeated pulses impressed upon the electronic stream bombarding each sequential anode as the switch arm 6| revolves at a rate which produces a charging of the anodes at a rate greater than the persistence of vision.

Fig. 14 is an enlarged vector analysis of the bombardment eiTect produced by successive pulses supplied to the electron stream between cathode 56 and one of the sequentially spaced electrodes from which characteristic curve T represents the rising and falling characteristic of the half wave rectifier system 98a, while curve T represents the rising and falling characteristic of the half wave section 98?) of rectifier 98 for a voltage e and for a time period which in the case of industrial power at source 91 of 60 cycles per second represents of a second or wherein each pulse occupies of a second. During these two successive pulses the molecules of gases are violently agitated producing a ray at a frequency that in turn will excite the fluorescent material used in the tube.

Fig. 15 illustrates the ionization time which is effective during the building up and decay of each current impulse. The portion of each characteristic curve T and '1 which is actually efiective for producing the ionization is that portion of each curve represented at I.

The energization of the tubes used in the system of my invention from volt 60 cycle current greatly increases the field of application of the sign of my invention and increases the brilliance of the fluorescence for reasons which may not be fully apparent upon initial consideration but which will be appreciated upon more thorough analysis. The cathode of each discharge tube is excited from 60 cycle alternating current. The opposite ends of the cathode change in polarity sixty times per second. The spaced anodes are excited by successive pulses of unidirectional current rising and falling at times per second. The change in polarity of opposite ends of the cathode and the gradual shift in polarity cyclically along the length of the cathode in coaction with the rising and falling pulses supplied to the spaced anodes coact to maintain a high active condition of ionization through the discharge path in the tube, as a result of which an extremely high brilliance in fluorescence is secured which is necessary in a display sign of the type to which applicant's invention is addressed.

I have employed the principles of my invention in a number of electronic animated advertising signs which I have operated with great success. The disclosures herein set forth contain preferred embodiments of my invention and I realize that various modifications may be made in the arrangement of circuits and details of construction and I intend no limitations upon my invention other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is as follows:

1. An electronic animated advertising sign comprising an evacuated tube of preformed shape containing a rare gas, a source of alternating current, a hot cathode in one end of said tube energized from said source, a multiplicity of sequentially spaced anodes within said tube in electron collecting relation to said hot cathode, a circuit for deriving full wave unfiltered rectified current from said source and for delivering unidirectional current impulses to the electron stream within said tube, means for selectively connecting said circuit to said sequentially spaced anodes for ionizing the discharge paths between said alternating current excited hot cathode and impulse excited anodes with unidirectional current impulses and effecting an emission of light rays for producing fluorescence.

2. An electronic animated advertising sign comprising an evacuated tube of preformed shape containing a rare gas, a hot cathode in one end of said tube, a source of alternating current, means for energizing said hot cathode, a multiplicity of sequentially spaced anodes within said tube in electron bombardment position relative to said hot cathode, a full Wave rectifier circuit for deriving unidirectional current impulses from said source and delivering successive unidirectional current impulses to the electron stream within said tube, means for selectively connecting said circuit to said sequentially spaced impulse excited anodes to produce a ray between said alternating current excited cathode and said successively energized anodes energized by said unidirectional current impulses at a frequency that will excite fluorescence in said tube according to a predetermined pattern, and cyclically driven means for deenergizing said circuit periodically upon completion of all of said anodes.

3. An electronic animated advertising sign comprising a multiplicity of evacuated tubes of preformed shapes each containing a rare gas and each including a hot cathode and a multiplicity of sequentially spaced anodes in electron bombardment relation to said hot cathode, a source of alternating current, means connecting said source and each of said hot cathodes for energizing said cathodes, a full wave rectifier circuit for deriving unidirectional current impulses from said source, means for selectively delivering said unidirectional current impulses to the sequentially spaced anodes of each of said tubes for ionizing the discharge paths between said hot cathode and the excited anodes in each of said tubes, and means for maintaining the excitation of the last of the anodes in one of said tubes while selectively exciting the anodes in the other of said tubes by unidirectional current impulses for establishing fluorescence between said alternating current excited cathodes and the impulse excited anode.

4. An electronic animated advertising sign comprising a multiplicity of evacuated tubes of preformed shapes each containing a rare gas and each including a hot cathode, a source of alternating current, means connecting said source and each of said hot cathodes for energizing said cathodes and a plurality of sequentially spaced anodes in electron bombardment relation to said hot cathode, a full Wave rectification cincuit connected with said source for deriving unidirectional current impulses from said source, means for selectively delivering said unidirectional current impulses to the sequentially spaced anodes of each of said tubes for ionizing the discharge paths between said alternating current excited hot cathode and the impulse excited anodes in each of said tubes, means for maintaining the excitation of the last of the anodes in one of said tubes while selectively exciting the anodes in the other of said tubes by unidirectional current impulses, and means for cyclically interrupting said circuit upon completion of excitation cf all of said anodes in succession.

5. An electronic animated advertising sign comprising a multiplicity of coacting evacuated tubes each containing a hot cathode and a plurality of sequentially spaced anodes, a source of alternating current, means connecting said source and each of said hot cathodes for energizing said cathodes, a multiplicity of full wave rectification circuits for deriving unidirectional currentimpulses from said source and switching means for sequentially delivering unidirectional successive current impulses from one of said circuits to the sequentially spaced anodes of one of said tubes and cyclically deliverin successive unidirectional current impulses to the anodes of others of said tubes from another of said circuits for establish- 10 ing fluorescence between said alternating current excited cathodes and said impulse excited anodes.

6. An electronic animated advertising sign comprising a multiplicity of coacting evacuated tubes each containing a rare gas, a source of alternating current, a hot cathode energized from said source and a plurality of sequentially spaced anodes in electron bombardment relation to the hot cathode in said tube, a plurality of circuits for developing full wave unfiltered rectified current from said source for delivering unidirectional successive current impulses and a switching system for selectively connecting one of said circuits with the sequentially spaced anodes in one of said tubes and successively connecting the sequentially spaced anodes of the others of said tubes with another of said circuits for producing a cyclically repeating animated fluorescent effect through said tubes under excitation of the unidirectional current impulses between the alternating current excited cathodes and the impulse excited anodes.

7. An electronic animated advertising sign comprising an evacuated tube containin a rare gas, a source of alternating current, a hot cathode energized from said source, and a multiplicity of sequentially spaced anodes in electron bombardment position with respect to said hot cathode, a full wave rectifier circuit connected with said source of alternating current for deriving unidirectional current impulses, and means for selectively connecting said circuit to said sequentially spaced impulse excited anodes for charging said anodes by activation under control of the unidirectional current impulses at a rate greater than the persistence of vision and producing flowing fluorescence in said tube between said alternating current excited cathode and said impulse excited anodes.

8. An electronic animated advertising sign comprising an evacuated tube containing a rare gas, a source of alternating current, a hot cathode energized from said source, and a multiplicity of sequentially spaced anodes in electron bombardment position with respect to said hot cathode, a circuit for deriving unidirectional current impulses from said source, means for selectively connecting said circuit to said sequentially spaced anodes for charging said anodes by activation under control of the unidirectional current impulses at a rate greater than the persistence of vision and producing flowing fluorescence in said tube between said alternating current excited cathode and said impulse excited anodes, effecting a recycling operation, and means for interrupting said circuit between said first mentioned operation and each of said recycling operations for correspondingly interrupting the fluorescence of said tube.

RICHARD H. SEAM'AN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,446,247 De Forest Feb. 20, 1923 1,662,114 Hotchner Mar. 13, 1928 1,899,670 Chromy Feb. 28, 1933 1,906,046 Chromy Apr. 25, 1933 2,295,869 Seaman Sept. 15, 1942 2,298,904 Scott et a1. Oct. 13, 1942 2,348,054 Burney May 2, 1944

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