DE1063202B - Arrangement for the suppression of microphones in television recording tubes - Google Patents

Description

GERMAN

The invention relates to television pick-up tubes in which the storage array is provided by a cathode ray is scanned and the storage arrangement has a high-resistance charge storage plate which arranged on the side facing the image converter room at a small distance from a metallic network is. Such television pickup tubes are known as picture orthicon or superorthicon tubes.

A disadvantage associated with the image orthicon or superorthicon is that caused by the relative movement Microphony caused between the storage disk and the neighboring network. Cause such relative movements a change in the effective capacitance with a corresponding change in the image signal output voltage. The movement is generally mechanical resonance, and resonance vibrations are often triggered by relatively small mechanical shocks or vibrations. The effect is similar to the microphone in electronic tubes.

Microphony occurs particularly with tubes that have a screen construction of larger diameter to have. In such tubes the storage plate, usually a thin membrane-like sheet of glass, is from the net at the edge through an annular spacer or a spacer ring (washer) separated, with the three parts - plate, spacer ring and net - · layered with the spacer ring than the middle class are bracketed together.

An improvement in terms of microphony can be achieved in that the ring-shaped The spacer is replaced by a pair of strip-like spacers that look like strings on the normally round screen shape are attached, which disrupt the circular symmetry of the screen and thus the Reduce microphony. However, only the normally annular spacer gets through this Replaced strip-shaped spacers, the disadvantage remains in practice that during the degassing step a differential displacement in production, in which the parts are heated under vacuum can occur between the spacers and the screen frame, and this causes often the spacers become wavy. This ripple does not go away when the tube after the Heating cools down and naturally creates a greater gap between the network and the storage disk than the target distance, d. That is, the distance is greater than the thickness of the undeformed one that has not become wavy Spacer. This is an unacceptable mistake, as it is found in all constructions of a tube of the The specified network storage disk spacing is maintained with a very high degree of accuracy must become. The present invention seeks

arrangement
for microphone suppression
in television tubes

Applicant:

English Electric Valve Company Limited, London

Representative: Dr. W. Müller-Bore and Dipl.-Ing. H. Gralfs, patent attorneys, Braunschweig, Am Bürgerpark 8

Claimed priority:
Great Britain May 20, 1957 and March 4, 1958

Walter Ernest Turk and Eric Douglas Hendry,
Chelmsford, Essex (UK),
have been named as inventors

To create tubes of the kind mentioned which have good anti-microphonic qualities, d. H. at them Vibrations of the storage disk and the network are reduced to a minimum, and that further can be produced with great accuracy.

According to the invention, this object is achieved in that to reduce microphonic Vibrations of the storage arrangement outside the scanning area above the storage arrangement are strip-like Spacers are attached between the network and the storage disk, which are attached to one part are, which serves as a support for the network and to which the network is attached at the same time, the Spacers have mechanical contact with both the storage disk and the network.

In one embodiment, strip-like spacers are used, which are normally a round umbrella structure are attached to this as tendons.

In another construction, a spacer in the form of a rectangular frame is used, its Corners are welded to the net support or otherwise attached. You can use four separate strip spacers be welded at their ends to the mesh carrier, either in the form of a Rectangle or an incomplete rectangle that • has gaps at the corners can be arranged.

The spacing devices are preferably worked in duplicate and consist of two parts of one Low thermal expansion material that

909 607/165

Claims (1)

1065 202 3 4 placed on top of one another and connected at the ends of the retaining ring 3 lying flat and circular (as well as with the net support). It's surface is welded on. It has been shown that with this double construction, as in FIG. 3, with the aid of the spacer, very good anti-so-called support or external clip microphone properties were actually achieved. Where 5 ring 9, of the tabs 10 has, held together, such spacers coupled to each other at four of these link plates 2 are visible in Fig.. These their ends welded to form a rectangle, are in the last stage of the assembly from, it is preferable to weld not all compliance of the drawing plane of FIG. 2 challenges, and then to the other set (as the result of quite far from the edge of part bent around 8 in order, is removed as at 10 ideally flat spacers) but io in Fig. 3, to form hook-like staples, instead, the spacer strips that hold together at their welding the assembled parts,
make to overlap, because when this happens, in Fig. 2 , for the sake of simplicity and the deviation from the ideally flat spacer, clarity of the drawing sieve and glass, which are narrower, since the difference in height between the upper door is obviously all over the central opening of the screen surface of a doubled strip and the upper 15 structure extend, treated as if both surfaces of the next strip welded to it were transparent, and the numbers 1 and 7 are therefore only the thickness of one of the two parts, both on the central opening of the umbrella structure from which each strip is composed. It applied while the inner edge unddieKante4, but as already mentioned, preferred exceed the net support ring both of which are drawn as circles, the ends of all the strips are not together directly 20 It is to be noted that the clamp ring 9 also menzuschweißen but in an incomplete still with a pair of hooks 11 ( not to be arranged in a rectangle in Fig. 3 ), which has the usual purpose of the-The invention is shown in the drawing and explains the mounting of the umbrella structure in the rich in connection with it . term location within the tube to facilitate. 1 is a purely schematic representation of a 25 Picture orthicon tube as a whole; Patent claims: Figure 2 shows a front view of a preferred one
Screen structure according to this invention, and 1. Arrangement for suppressing the micro-fig. 3 shows a detail section in substantially GroE phonie in a television pick-up tube in which ßerem scale than in Fig. 2 and in detail the con- 30, the memory device of a cathode-ray structural tion at the edge of the shield structure. The tube shown in Fig. 1 is of a generally high-resistance charge storage plate of the known type and contains on one side of the evacuated piston B (only partially drawn) at a small distance from a metallic one on one side of the evacuated piston B (only partially drawn) on the side facing the image converter chamber a photocathode P is arranged on the rear wall of the tube, 35 network, characterized in that an accelerating anode A, a storage device strip-like shielding structure above the storage arrangement, which is in a cylindrical-conical holder (5 and 6) between the network (1) and the frame TF is held, a net-shaped electrode of the storage plate (7) are attached, which are attached to trode F, which is used when the tube is in operation, a ring (2), which serves as a support for a uniform electrostatic field, and 40 the network is used and at the same time the network is a braking electrode D. The present invention is attached, and that the spacing dhaltenden Streib relates to the construction of the screen structure T, the fen is shown purely schematically with both the storage disk and in Fig. 1. have mechanical contact with the network. According to FIGS. 2 and 3 , the umbrella structure contains a second tube according to claim 1, characterized by a fine wire mesh 1, which extends over the opening of 45 , that the umbrella structure is round and the mesh carrier ring 2 extends. The edge of the net-strip-like spacers as tendons of the circular area will be arranged in a recess of the net-carrier circular area,
ring 2 held by a flat ring 3, which is welded to 3. tube according to claim 1, characterized gekennder surface of the recess and characterized so that the spacer holds a Ahden edge of the mesh surface firmly in this position. 50 stand holder in the form of a rectangular frame. The mesh surface is fixed by pulling it over the edge 4, the corners of which are stretched flat over the opening of the carrier ring 2 on the mesh carrier part. as can be clearly seen from FIG. 3. Parallel to and 4th tube according to claim 1, characterized by a distance from the network 1, there is a high-resistance glä- records that the spacing devices have four central charge plate 7, which have strip spacers separated on their circular 55 , which are attached to a so-called faceplate ring 8 in the edge are arranged in the form of a rectangle, which is attached to an angular cross-section to which the measure is that its corner points is melted outside the glass. The required distance between the network 1 and the ends of the strip spacers on the network faceplate 7 is fixed by a pair of strip-like 60 carriers. Spacers 5/6 adhered to, which are arranged like a chord for the screen structure 5. Tube according to one of the preceding views (see Fig. 2) and each from sayings, characterized in that in the two superimposed layers of a material stand device use strip spacers with low temperature coefficients . The each of two parts of a Mazwei The det, layers that make up each strip are 65 terials shown with a low temperature coefficient Bebei 5 and 6 in Fig. 3 and medium are provided at their ends, which lie on one another and welded at their ends to each other , wherein the lower layer 5 is connected to one another and attached to the mesh carrier one provided on the carrier ring 2 and attached to the outside. 1 sheet of drawings © 909 607/165 8. 59