DE1163463B - Process for the manufacture of an electron beam scanning tube with a vapor-deposited, photoconductive target plate and arrangement for carrying out this process - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Kl .: H Ol j

German class: 21 g - 13/25

Number: 1163 463

File number: N 16703 VIII c / 21 g

Filing date: May 12, 1959

Opened on: February 20, 1964

The invention relates to the manufacture of an electron beam scanning tube with a vapor-deposited, photoconductive target and a cylindrical piston that has a Window is provided which forms the support for the target, and that at the other end in one Ending foot of an electrode system with an electron gun carries, in which an evaporator carried by the electrode system with photoconductive material in the with a pump set connected flask is inserted so that the evaporator reaches the window and the photoconductive material when the evaporator is heated to form the target on the window is vaporized. An example of such a tube is a Vidikon type television pickup tube. The invention also relates to an arrangement for carrying out such a method.

The photoconductive properties of certain plate materials can be impaired if the material comes into contact with air after vapor deposition. In a known method for producing the target plate for a pick-up tube of the Vidikon type, whereby contact between the vapor-deposited plate and the open air is prevented, the cylindrical piston is first provided with a transverse side arm which extends to the piston close to its end face or Window connects. The end face forms the carrier on which the plate material must be attached. In the stage in which the electrode system is arranged in the flask and a glass base is fused to the flask, the air is pumped out of the flask and argon or another inert gas is introduced under low pressure. During the time in which the piston is then with the end face up and the side arm horizontal, a crucible with photoconductive material in the side arm is guided into the axis of the piston at a certain distance below the catching grid of the electrode system, which grid is close to the end face of the piston is located. The crucible, catch grid, and anode near the crucible are then heated, causing the photoconductive material, usually antimony trisulfide, to vaporize and deposit through the hot catch grid onto the end face of the piston. The inert gas is then pumped away by a pump; the vent tube fused to the base is melted shut and finally the crucible is withdrawn into the side arm, which is then separated by melting close to the piston. Although here a method for manufacturing an electron beam scanning tube with a vapor-deposited,
photoconductive target and arrangement
to carry out this procedure

Applicant:

N.V. Philips' Gloeilampenfabrieken, Eindhoven

(Netherlands)

Representative:

Dr. rer. nat. P. Roßbach, patent attorney,

Hamburg 1, Mönckebergstr. 7th

Named as inventor:

Andrew Alfred Turnbull, London

Claimed priority:
Great Britain May 15,
December 11, 1958 (No. 15,652)

a contact between the plate and the air is avoided, this method has the disadvantage that the Impact plate by vapor deposition of the plate material through the safety grid of the electrode system is made, making uniform layers difficult to achieve, while also the The bulge of the piston caused by the melting away of the side arm acts as an obstacle.

It is also already known to have a suitably shaped one between the target plate and the safety gate To arrange metal ring, which is vapor-deposited with the semiconductor material before installation in the tube and is heated by an RF field after installation in the tube. However, this method has the Disadvantage that the metal ring, which is no longer required after evaporation, remains in the tube.

The disadvantages of the known methods are addressed in a method of manufacturing an electron beam scanning tube with a vapor-deposited, photoconductive target according to the invention thereby avoided that the foot with the electrode system located above it in the one with a side arm provided lower part of a vertical tube, the upper part of which is closed by a window forms the bulb of the discharge tube to be manufactured, is introduced and then together with one loosely placed on the electrode system

409 509/312

when the method according to the invention is carried out in a somewhat different manner.

F i g. 1 shows an elongated glass tube 1, the upper part 2 of which is later to form the piston of a receiving tube of the Vidikon type. At the upper end of the tube 1 an end surface or a window 4 made of glass is fused by a flat ring 3 made of nickel iron, on the inner surface of which a transparent, conductive layer is applied. Vicinity

Evaporator with photoconductive material pushed into the upper part and into the to form the The target is placed on the window suitable evaporation layer after forming the The target plate is withdrawn from the electrode system in the lower part of the vertical tube after which the evaporator by means of movable means in the side arm of the electrode system removed and pulled into the side arm

until finally the foot with the electrode io the lower end of the tube 1 is a freezing system again provided in the upper part of the vertical pocket 5; the liquid air for the exhaust pipe pushed and the foot under upright freezing is marked with 6 and the outermost, lower one Creation of a vacuum in the tube all around with the end of the tube 1 is through a greased, konisclies Wall of the upper part fused and the upper contact strip and through another pipe 8 with a Part of the tube below the fusion point 15 is connected to the vacuum pump 9.

is separated from the remainder of the pipe. From the tube 1 extends below the

This method can be used both in the cases of part 2 a side arm 10, which is a cylindrical in which the photoconductive material part 11 and part 12 with a larger transverse im Vacuum is to be applied as well as containing in dimension. Inside the cylindrical part Cases where the vapor deposition in an inert 20 11 is a metal block, e.g. B. made of iron, provided Gas should take place under low pressure. Known, which forms a sliding tension and a fork 14 it supplies antimony trisulphide, which carries as a photoconductive one, which has two prongs 15. The block 13 can Material is common, a target layer with within the part 11 of the side arm 10 according to the a higher specific dark resistance when the axis of the tube 1 is moved towards and away from it in an inert gas under reduced pressure by means of a ring-shaped magnet 16, the is steamed. If the evaporation in a gas surrounds the outside of the part 11 and in a horizontal atmosphere occurs, it is of course necessary to move the block 13 with it. Means agile, in one of the process stages the gas from the magnet 16 can the prongs 15 of the fork 14 dissipate the envelope. This can be done partially, inserted into the tube 1 and into the part 12 of the before the foot is fused to the shell, 30 side arm 10 are moved back, while the final, complete venting through the wall of the pipe 8 is a white

a separate pump is passed through a glass tube 17 on top of it, which has an open, upper one tied vent tube takes place. Part 18, which is coaxial in the pipe 1

In the process, the electron beam can stretch and end above the freeze-out pocket 5. Near the generation system of the electrode system of the tube 35 the end of the tube part 18 are a number of fully or partially activated and / or degassed openings 19 are provided, only one of which is provided before melting or even before the target is formed. Activation and / or degassing preceding the formation of the plate has the
Advantage that during these processes, any 40
developing gases, which could otherwise affect the plate, must be removed beforehand.

The evaporator can be formed by a crucible. If the evaporation of the plate in a

Gas atmosphere takes place, the vaporizer has in front of the electron gun 24 facing away from the end of the preferably the shape to be described below; Fan anode, this anode has a catch grid 25. That

indicates is. Outside the tube 8 is the tube 17 with a mercury manometer 20 and through a Cock 21 with an argon container 22 in connection. Inside the tube 1, between the side arm 10 and the cooler 5, the electrode system for the pickup tube is arranged. This system exists from an anode 23 and an electron gun 24, which is shown schematically. To the

it is provided with a number of openings, through which convection currents of the gas can flow during the evaporation.

Electrode system is held by holding rods 26, which are connected to the glass base 27, the outer diameter of which is slightly smaller than the clear

Figures 1 to 6 show vertical sections through 50 meters of the tube 1, whereby the electrode is a Device for exercising the method, where the foot in the longitudinal direction in the system at various stages of manufacture for a television pick-up tube of the Vidikon type are shown;

Tube 1 is slidable. If desired, the foot 27 can be provided on the edge with an upturned, be provided flange-shaped ring. The foot 27 has

sighting another form of vaporizer; 55 a vent tube 28, which is usually through F i g. 9 shows a part of a small glass bulb 29 closed in a vertical section. By

A number of electrode pins 30 are passed through the foot 27, only two of which are shown. Below the glass base 27 is a tube socket 31 is arranged, the a number of upward Has metal lines 32 which are provided with trough-shaped end pieces 33 into which the Ends of pins 30 go in. The conductors 32 extend through the tubular socket 31 and terminate

Section of another form of releasable fastener 65 below that in resilient contacts 34, the

of an evaporator according to FIGS. 7 and 8, and lie resiliently against the inner wall of the tube 1.

Fig. 12 shows a vertical section through a tube socket 31 has a tubular extension

Variation of part of the device according to FIG. 1, including 35, which is in a recess 36 in the upper surface

7 and 8 show side and top views

the device for vaporizing photoconductive material from the vaporizer according to FIGS. 8th and 9, corresponding to the production stage according to FIG. 2;

F i g. Fig. 10 shows in a vertical section a device for applying the photoconductive material on the evaporator according to FIGS. 8 and 9; Fig. 11 is a side view and partly a

a cylindrical iron block 37 is cemented, which also has a recess 38 in the lower surface, so that the block 37 can rest on the upper part 18 of the tube 17. The block 37 has a number of channels 39 which run through the whole block.

The anode 23 of the electrode system is held centered in the tube 1 by centering springs 40, the one near the top of the anode 23

Tube 1 arranged tub 43 made of stainless steel is welded, which is an inner lining of silicon oxide or platinum and in which there is a lot of antimony trisulfide 44.

By means of an annular magnet 45 which surrounds the block 37, the electrode system can with the foot 23 to 27, which system rests indirectly on the block 37, in the pipe 1 upwards and

27 is then brought further down into its original position (see Fig. 4) by the magnet 45, so that the block 37 rests on the end of the upper part 18 of the tube 17. The bucket 43 is 5, however, held by the prongs 15 and the tube 41 detaches from the handle 42. The bucket 43 and the stem 42 is then withdrawn into the portion 12 of the side arm 10. For this purpose, the block 13 is by means of of the magnet 16 is moved to the left until the location

are welded to this anode. On the exterior io according to fig. 4 is reached. surface of the anode 23 on which the electron beam The electrode system 23 to 27 is then re-

Generation system 24 facing away end, is one of the by the magnet 45 in the position according to FIG. 5 metal or ceramic tube or a socket in which the grille 25 is fixed in an Ab-41 with a small diameter, from which (which) stood about 2.5 mm from the plate layer 52, a stem 42 in the form of a curved 15 cherishes. In this position, the spring contacts 34 push a wire on which one in the axis of the platinum contacts (not shown) can be applied to which suitable electrode voltages can be applied in order to activate the cathode of the electron gun. The tube 1 is vented by the ao pump 9 to a pressure of about 10 ~ ⁷ mm Hg, whereupon the cathode is activated.

The pump 9 is kept in operation during the activation of the cathode in order to remove any gases which have been evolved. After activation and can be moved down. In the illustrated 25 the suction of any evolved gases of the device, the magnet 45 has a gap through the upper part 2 of the tube 1 around the glass base 27, which the magnet moves past the side arm 10
can be.

The upper part 2 of the pipe 1 is surrounded by a cooling jacket 46 which contains water 47. At 48 30 a rubber seal is indicated. A ring 49 made of stainless steel surrounds the ring 3.

While the cock 21 is closed, the pipe 1 is brought to about ΙΟ " ⁶ mm Hg by the pump 9

vented. The openings 39 in the block 37 contribute to the 35 extending 27, is removed and the vent Vent pipe 1 at. The pump tube 28 is secured to a glass tube 43 then melted by a tap, not shown, which leads to a pump 54 (see Fig. 6). closed and the cock 21 is opened to The tube 53 has a piston-shaped side piece 55, Argon from the container 22 through the openings in which a metal ball 56 is housed, the 19 in the upper part 18 of the tube 17 in the 40 is moved up by a magnet, not shown Guide pipe 1. If the pressure gauge 20 can be used to break the piston 29, where-argon pressure of a few millimeters of Hg through the space in the envelope 2 with the pump 54 in the cock 21 is closed. The freezing pocket 5 connection occurs. Any, during the melting prevention, that vapor of the sealing grease of the cones of the foot 27 developed in the casing 2 and watched Connection 7 of the electrode system of the remaining gases are then passed through the reached receiving tube. Pump 54 is pumped away until the pressure is about

The electrode system 23 to 27 will then be 10 ~ ⁷ mm Hg or less; then by means of the magnet 45, which surrounds the iron block 37,
moved up until the situation according to FIG. 2 is reached,

in which the bucket 43 is about 2.5 cm from the window 4 50. In the method described, are particularly removed. Eddy current induction precautions are then taken to prevent any occurring during the coil 50 caused by a high frequency power source 51
is fed, via the jacket 46 around the bucket 43
pushed down, which is heated so far that the antimony trisulfide evaporates from the bucket and can be kept very low on 55 becoming gas to the window 4 in the form of an impact plate layer and that when using an effective pump 9 52 precipitates. The ring 49 takes up the electrical power to a flat foot or a flange foot without venting energy in the area of the window 4 and a small tube can be used, protects the ring 3 from undesired heating

Coil 50 is then removed and the cooling water 60 by means of the device described is a new one jacket 46 is removed. The bucket 43 cools the electrode system within the remaining on it and the electrode system 23 to 27 part of the tube 1 is arranged, whereupon a new one through the magnet 45 downwards into the position shown in FIG. 3 piston part is fused to tube 1, where the location shown. If the original part 2 was cut off in this position. To this Magnet 16 is moved to the right, the block 65 being the part of the device with the way 13 in the cylindrical part 11 of the side arm 10 side arm 10 and all according to FIG. 1 inserted underneath is, the prongs 15 below the elements together with the bucket 43 are many of the bucket 43 brought. The electrode system can be used 23 times.

melted while the pump 9 remains effective to prevent any protruding from the glass Remove gases.

Air is then let into the pipe 1. Then the pipe is at a certain distance cut below the foot 27, so that the shell 2 of the receiving tube is free. That still attached part of the tube 1, which extends past the foot

the vent tube 28 closed at 57 near the foot 27.

Fusing the foot 27 of the receiving tube to the piston 2 to remove any gases evolved. It has However, it has been shown that in practice the amount is free

7 8

The described device has the advantage that evaporation of the Antimontrisulfids is the bell 65, the degassing of the sheath 2 and the electrode system can be initially ent-23 performed at 10 ~ ⁴ mm Hg by the pump 69 to 27, before the up-ventilated and the Crucible 70 is then evaporated through the target layer 52. Heated in front of the stream of source 75. During this evaporation, degassing, the evaporator 42, 43 with the 5 in a vacuum, a very uniform layer of the photoconductive material 44 can be obtained by means of the spiral 60. The fork 14 is then guided into the side arm 10. The elec- tric vacuum released. The spiral coated with photoconductive matrix system 23 to 27 is then moved in the longitudinal direction from the part of the tube 1 with the side electrode system of the discharge arm 10 to be produced into the upper part 2 in a detachable manner. The degassing tube is attached as shown in FIG. 9 is indicated. of the electrode system 23 to 27 and of part 2 Fig. 11 shows a variant of the assembly of the device carried out by a cylindrical furnace, steam according to Fig. 7, the spiral 60 being pushed through the over the part 2 (during which a wire bridge 80 on a round cover plate 81 cooling jacket is not present); the temperature is fixed above the end of the anode 23 of the furnace is about 350 ° C. During the degassing 15 can be pushed (Fig. 9), during the foot gassing, the vacuum in the tube 1 is created by means of the piece 41 in this case is omitted. Maintain pump22. After degassing, Fig. 12 shows a variant of part of the Einrichwird the electrode system 23 to 27 in the lower device according to FIG out and the evaporator 43 is from the side 20 that of the remaining part of the tube. With the Einricharm 10 pushed and releasable at the end of the catch according to FIG. 12, the evaporator according to FIG. 11 anode 23 attached, whereupon the electrode system is arranged, which shows that the spiral 60 rests on the cover plate 81 and the evaporator in the already described position, which come over the end of the catch for evaporation of the impingement plate 52. anode 23 of the electrode system 23 to 27 is in. In a variant of the method, the bucket 43, 25 is such that the plate can be easily lifted from the anode 23 from which the photoconductive material is evaporated. The electrode system 23 by a flat metal spiral 60 with a cover 27 is similar to that according to FIG. 1 and is applied to the same layer 61 of photoconductive material according to the manner through the tube socket 31 by means of conductive FIG. 7 and 8 replaced. So that the spiral is supported by holding rods 32, but the tube eddy currents can be heated, the outer 3 ° version 31 does not have a tubular extension 35, turn of the spiral is bent at 62 and with what in the device according to FIG. 1 is the case. Wire 42 connected to serve as a support for the spiral conductors 32, only two of which are shown. the number of which, however, corresponds to that of the electrode pins. Apart from the replacement of the bucket by the speaks, but grip the tube socket 31 and are spirals, the method is connected in the manner described above to the conductors 82, which are carried out in a manner described. However, it has been shown to extend a certain distance within the tube 1 that in the stage in which the photoconductive and the mount 31 and the electrode system 23 material on the window 4 according to FIG. 9 evaporated until 27 rest on an iron block 83, the spiral 60 (shown in cross section) The block 83 consists of a number of closer to this window than 40 different isolated segments, each with a line in the bucket 43 is the case. 82 is electrically connected.

In a given case in which the piston is the through the wall of the tube 8 is a number of

Pick-up tube an inner diameter of 23 mm lead wires 84 passed through each

and the effective surface of the target a segment of the block 83 down to the area of the

The 45 side arm 10 had dimensions of 12.5 x 9.6 mm. The wires 84 are in

Spiral 60 slidable through five turns of tungsten wire with block 83 so that when block 83

formed with a diameter of 1 mm. The spiral in the pipe 1 is moved up by means of the annular

60 had a diameter of 22 mm, the win magnet 85, the electrical connection between

The connection spacing on the outside was slightly smaller for the wires 84 and the electrode pins 30 of the

than the one in the middle. 50 electrode system is not interrupted.

You can put photoconductive material on the spiral. The sequence of operations is similar attach by it in the vacuum of the device which is based on the F i g. 1 to 6 described according to FIG. 10 is evaporated. is. The block 83 is raised to high-F by means of the magnet 85 i g. 10 shows a bell 65 which moves on a flat around the electrode system 23 to 27 and the Base plate 66 rests; a sealing ring is with 67 55 resting on it evaporator coil 63 in the upper designated. The space in the bell 65 is to be fed through part 2 of the tube 1, with the springs 40 a pipe 68 connected to a pump 69 to keep the system in part 2 central. The electrode this To vent the room. On the base plate 66, the system is moved up until one evaporates inside the bell 65, a platinum crucible 70 suitable position is reached, whereupon the photo brings, which contains a lot of antimony trisulfide. 60 conductive material 60 by eddy current heating Crucible 70 is electrical with terminals 71 and measured F i g. 9 evaporates. The system is on it 72 connected, which is moved downward through the base plate 66 and by means of the fork 14, which is attached to the leads and through conductors 73 and 74 with a current block 13 in the cylindrical part 11 of the side arm 10 source 75 are connected. Attached to the base plate 66 in FIG. 6 are the spiral and the cover plate the bell 65 is a support 76 with an arm 77 65 in the side arm 10 withdrawn on the hand arranged, whereby the wire 42 with the coil of the evaporator 43 of FIG. 3 and 4 described just above the crucible 70 at a distance of way. The electrode system is on it again z. B. 11.5 cm can be held. Moved upwards to the final desired position

in the sheath 2; the corresponding position 85 'of the magnet 85 is indicated in dashed lines. The electrode system is activated and the foot 27 becomes fused to part 2 as described above. The one to activate the electrode system required voltage is supplied through wires 84.

It will be evident that when the electrode system 23 to 27 is pushed up in the tubular part 2 the cover plate 81 extends almost entirely over the cross section of the end part 2 of the tube 1. The cover plate 81 thus greatly reduces the possibility of the evaporative, photoconductive Material on one of the electrode parts, in particular on the cathode of the electron gun 24, which adversely affects the operation of the electron gun could be.

Although according to FIG. 12, the cover plate 81 and the end of the anode 23 are shown to match, this is not necessary; the cover plate can simply consist of a flat disc that is on the end the anode 23 can rest.

Claims (12)

Patent claims: 1. A method of manufacturing an electron beam scanning tube having a vapor deposited photoconductive one Target and a cylindrical piston that has a window at one end is provided, which forms the carrier for the target, and that at the other end in one Ending foot that carries an electrode system with an electron gun, in which an evaporator carried by the electrode system with photoconductive material in the with A piston connected to a pump set is introduced in such a way that the evaporator is in front of the Window arrives and the photoconductive material when the evaporator is heated to form the Impact plate is vapor-deposited onto the window, characterized in that the foot (27) with the electrode system (23, 24) located above it in the one with a side arm (11, 12) provided lower part of a vertical tube (1), the closed by a window (4) upper part (2) forms the bulb of the discharge tube to be manufactured, is introduced and then together with an evaporator loosely placed on the electrode system (23, 24) (43) with photoconductive material (44) pushed into the upper part and into the to form the The target is placed on the window (4) suitable evaporation layer to after Forming the target of the electrode system (23, 24) in the lower part of the vertical tube (1) to be withdrawn, after which the evaporator (43) by means of movable means (13, 14, 15) in the side arm (11, 12) removed from the electrode system (23, 24) and in the Side arm (11, 12) is pulled in until finally the foot (27) with the electrode system (23, 24) is pushed again into the upper part (2) of the vertical tube (1) and the foot (27) is maintained a vacuum in the tube (1) fused all around with the wall of the upper part (2) and the upper part (2) of the tube (1) below the fusion point of the remainder Part of the tube (1) is separated. 2. The method according to claim 1, characterized in that the electrode system (23, 24) and the end part (2) of the tube (1) with the window (4) degassed prior to the formation of the target will. 3. The method according to claim 2, characterized in that first the evaporator (43) brought into the side arm (11, 12) with a supply of photoconductive material (44), thereupon the electrode system (23, 24) present in the pipe part (1) is pushed into the end part (2) whereupon this part and the electrode system are degassed by heating and the electrode system (23, 24) pushed back in the pipe part (1), the evaporator (43) from the side arm (11, 12) guided into the tube (1), loosely placed on the electrode system (23, 24) and from this is brought into the desired distance to the window (4). 4. The method according to claim 1, 2 or 3, characterized in that in the formation of the Red target in an inert gas under reduced pressure as a photoconductive material Antimony trisulfide is used. 5. The method according to claim 1, characterized in that that the foot (27) is provided with a fused vent tube (28), which after the separation of the at the foot (27) Fused end part (2) of the tube (1) brought into connection with a vacuum pump is broken, the melt (29) of the vent tube is broken to the Bring the inside of the piston into contact with the vacuum pump, whereupon the piston completely evacuated and the vent tube is sealed close to the foot. 6. The method according to claim 1 or 3, characterized in that the movement of the evaporator (43) and / or the electrode system (23, 24) is achieved by magnets that are outside of the tube (1) or the side arm (11, 12) are arranged displaceably. 7. Arrangement for performing the method according to one or more of claims 1 to 6, characterized in that the evaporator has a number of openings through which convection currents of the existing in the tube during the evaporation of the target inert gas can flow, seen from the window (4), these openings and the parts of the evaporator coated with the photoconductive material are practically uniform are distributed in a cross section of the pipe. 8. Arrangement according to claim 7, characterized in that the evaporator by a Wire or a narrow strip of metal is formed, a number of spaced apart Has turns. 9. Arrangement according to claim 8, characterized in that the evaporator is spirally shaped is wrapped. 10. The arrangement according to claim 9, characterized in that the evaporator is in the form of a Has helical spiral. 11. Arrangement according to one of claims 7 to 10, characterized in that the photo 409 509/312 conductive material is attached to the evaporator by vapor deposition in a vacuum. 12. Arrangement according to claims 7 to 11, characterized in that the evaporator is carried by a support (81) which is capable of evaporating the target plate 12 extends almost entirely over the cross section of the end part (2) (Fig. 12). Older patents considered: German Patent No. 1 049 423. In addition 3 sheets of drawings 409 509/312 2.64 © Bundesdruckerei Berlin