US3860851A - Gauze electrode for a cathode-ray tube - Google Patents

Gauze electrode for a cathode-ray tube Download PDF

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Publication number
US3860851A
US3860851A US404340A US40434073A US3860851A US 3860851 A US3860851 A US 3860851A US 404340 A US404340 A US 404340A US 40434073 A US40434073 A US 40434073A US 3860851 A US3860851 A US 3860851A
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gauze
electrode
aperture
gauze electrode
cathode
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US404340A
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Willem Antonius Maria Hamersma
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US Philips Corp
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US Philips Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/025—Mounting or supporting arrangements for grids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/08—Electrodes intimately associated with a screen on or from which an image or pattern is formed, picked-up, converted or stored, e.g. backing-plates for storage tubes or collecting secondary electrons

Definitions

  • the invention relates to a gauze electrode for a cathode ray tube, which electrode is arranged at a small distance parallel to a signal plate and which is supported at the edge by at least one supporting ring, measures being taken to reduce microphony" interferences which may occur as a result of vibrations of the gauze electrode.
  • the invention relates in particular to a gauze electrode for a camera tube of the vidicon type.
  • the inner edge of at least one supporting ring of the gauze electrode encloses an aperture which mainly is in the form of a rectangle of which at least two oppositely located sides are curved, the wires of the gauze extending mainly according to the diagonals of the rectangular aperture.
  • the corners of the rectangle are preferably rounded off, so as to be able to better use the surface of the gauze.
  • the curved sides of the aperture preferably extend convex relative to the centre of the aperture. Preferably, all four sides are shaped in this bent manner.
  • the radius of the curved sides is preferably approximately equal to the radius of the outer edge of the supporting ring.
  • a damping member of thin aluminum foil is known from the U.S. Pat. No. 3,287,585 which is provided as a spacing member between gauze and signal plate. It is stated that the aperture of said foil may be irregular and that finger-shaped projections may be present, if desired. However, such projections can only be used if the material thereof consists of a thin foil since otherwise they damage the gauze.
  • FIG. 1 is a longitudinal sectional view of a vidicon tube
  • FIG. 2 shows an embodiment of a supporting ring for a tube with rectangular picture scanning
  • FIG. 3 shows an embodiment of a supporting ring suitable for scanning both a rectangular and a circular disk-shaped picture
  • FIG. 4 is a part of a cross-sectional view of a gauze electrode according to the invention.
  • Reference numeral 1 in FIG. 1 denotes the wall of a vidicon camera tube which is closed by a glass plate 2.
  • a photosensitive signal electrode 3 is present on the inside of the plate 2.
  • the gauze electrode 4 is provided parallel to the electrode 3 and at a few millimeters dis tance therefrom.
  • the gauze 4 consists, for example, of wires of nickel or copper having a thickness of 4 p. and a center distance of 36 t. Instead of wires, the gauze electrode 4 may also be a perforated plate.
  • the gauze 4 is clamped between two supporting rings 5 and 7 which are secured together by means of a numher of spot welds along the circumference or by solder ing or diffusion.
  • the material of the ring 5 has a thickness of, for example, 0.5 mm
  • the material of the ring 7 is, for example, 0.1 mm thick.
  • the rings 5 and 7 consist of molybdenum when nickel gauze is used and of a chromium-nickel alloy when copper gauze is used.
  • an electron lens 6 is provided in the tube.
  • the supporting ring 7 shown in FIG. 2 comprises a mainly rectangular aperture the sides 8 and 9 of which are convex relative to the center of the aperture.
  • the corners are rounded so as to obtain a better use of the gauze surface.
  • the sides 9 are longer than the sides 8 so that this electrode is mainly suitable for scanning an elongate rectangular picture surface.
  • all sides 8 of the aperture are the same so that this electrode is suitable both for scanning circular disk-shaped pictures and for scanning rectangular pictures.
  • the wires of the gauze 4 extend approximately according to the diagonals of the mainly rectangular aperture.
  • the holes are provided in rows which extend approximately in the direction of the diagonals of the mainly rectangular aperture of the ring.
  • the parts of the sides 8 and 9 projecting inwardly may be bent out of the plane of the ring so that they slightly press on the gauze 4 and thus intensify the damping effect. It has been found that the damping of a ring formed according to the invention is approximately 20 times more effective than in the case in which a ring 7 is used having a rectangular hole with straight sides.
  • a rectangle may be used having two straight and two oppositely located curved sides, or the corners may not be rounded off, in which case a cushion-shaped aperture is formedv
  • the use of an aperture having more than 4 sides is more unfavourable according as the number of sides increases, since the circumference of the aperture increasingly approaches the circle, which is unfavourable with respect to the occurrence of vibrations.
  • the invention is also of importance for other cathode-ray tubes, for example, oscillograph tubes, and the like.
  • a cathode-ray tube having a target electrode at one end of an envelope and a gauze electrode spaced from said target electrode, the improvement comprising at least one annular member spaced from said target for supporting said gauze electrode with reduced microphonic interference, said annular member having an inner edge enclosing a substantially rectangular aperture having at least two oppositely located curved sides, said gauze electrode comprising wires extending substantially parallel to the diagonals of said rectangular apertures.

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  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
  • Electrodes For Cathode-Ray Tubes (AREA)

Abstract

A gauze electrode for a cathode-ray tube, in particular a camera tube, in which the aperture of the supporting ring is substantially rectangular the oppositely located sides of which are curved.

Description

United States Patent Hamersma 1 Jan. 14, 1975 GAUZE ELECTRODE FOR A [56] References Cited CATHODE-RAY TUBE UNlTED STATES PATENTS [75] Inventor: Willem Antonius Maria Hamersma, 3,287,585 l1/l966 Rundcls 4113/8) Emmasingel, Eindhoven, Nfitherlands OTHER PUBLlCATlONb Kuseman, Turget-to-Mesh Spacing Means for ()rthi- [73] Assgnee: Ph'hps Corporatmn, New con Tubes, RCA Technical Notes, August 1965,
York RCA TN No. 630.
[22] Filed: Oct. 9, 1973 Primary ExaminerJames B. Mullins [211 App! 404340 Attorney, Agent, or Firm-Frank R. Trifari; Curl P.
Steinhauser [30] Foreign Application Priority Data 0m. 27, I972 Netherlands 7214547 ABSTRACT A gauze electrode for a cathode-ray tube, in particular U-S. Cl. a amgra tube in the aperture of the upporting [51] Int. Cl. H01] 29/46 i i b t tially ectangular the oppositely located [58] Field of Search 313/65 R, 65 T, 74, 85 R, Sides f which are curved.
5 Claims, 4 Drawing Figures GAUZE ELECTRUDIE FOR A CATHODE-RAY TUBE The invention relates to a gauze electrode for a cathode ray tube, which electrode is arranged at a small distance parallel to a signal plate and which is supported at the edge by at least one supporting ring, measures being taken to reduce microphony" interferences which may occur as a result of vibrations of the gauze electrode. The invention relates in particular to a gauze electrode for a camera tube of the vidicon type.
It has already been tried in various manners to reduce the microphony effect of such a gauze electrode, for example, by providing rods or plates which, if desired, also serve as spacing members between gauze and signal plate (see British Patent Specification Nos. 984,673; 948,944 and 1,094,186) or by reinforcing the gauze by providing ribs in the gauze (German Patent Specification No. 1,237,168), However, these known measures are complicated and attenuate the vibrations of the gauze electrode only to an unsatisfactory extent.
A much simpler solution which provides a much stronger attenuation of the undesired vibrations of the gauze electrode is obtained if, according to the invention, the inner edge of at least one supporting ring of the gauze electrode encloses an aperture which mainly is in the form of a rectangle of which at least two oppositely located sides are curved, the wires of the gauze extending mainly according to the diagonals of the rectangular aperture. The corners of the rectangle are preferably rounded off, so as to be able to better use the surface of the gauze. The curved sides of the aperture preferably extend convex relative to the centre of the aperture. Preferably, all four sides are shaped in this bent manner. The radius of the curved sides is preferably approximately equal to the radius of the outer edge of the supporting ring.
A damping member of thin aluminum foil is known from the U.S. Pat. No. 3,287,585 which is provided as a spacing member between gauze and signal plate. It is stated that the aperture of said foil may be irregular and that finger-shaped projections may be present, if desired. However, such projections can only be used if the material thereof consists of a thin foil since otherwise they damage the gauze.
The invention will be described in greater detail with reference to the accompanying drawing, of which:
FIG. 1 is a longitudinal sectional view of a vidicon tube,
FIG. 2 shows an embodiment of a supporting ring for a tube with rectangular picture scanning, and
FIG. 3 shows an embodiment of a supporting ring suitable for scanning both a rectangular and a circular disk-shaped picture, while FIG. 4 is a part of a cross-sectional view of a gauze electrode according to the invention.
Reference numeral 1 in FIG. 1 denotes the wall of a vidicon camera tube which is closed by a glass plate 2. A photosensitive signal electrode 3 is present on the inside of the plate 2. The gauze electrode 4 is provided parallel to the electrode 3 and at a few millimeters dis tance therefrom. The gauze 4 consists, for example, of wires of nickel or copper having a thickness of 4 p. and a center distance of 36 t. Instead of wires, the gauze electrode 4 may also be a perforated plate.
The gauze 4 is clamped between two supporting rings 5 and 7 which are secured together by means of a numher of spot welds along the circumference or by solder ing or diffusion. The material of the ring 5 has a thickness of, for example, 0.5 mm, the material of the ring 7 is, for example, 0.1 mm thick. The rings 5 and 7 consist of molybdenum when nickel gauze is used and of a chromium-nickel alloy when copper gauze is used. Furthermore, an electron lens 6 is provided in the tube.
The supporting ring 7 shown in FIG. 2 comprises a mainly rectangular aperture the sides 8 and 9 of which are convex relative to the center of the aperture. The corners are rounded so as to obtain a better use of the gauze surface. The sides 9 are longer than the sides 8 so that this electrode is mainly suitable for scanning an elongate rectangular picture surface.
In the embodiment shown in FIG. 3, all sides 8 of the aperture are the same so that this electrode is suitable both for scanning circular disk-shaped pictures and for scanning rectangular pictures. The wires of the gauze 4 extend approximately according to the diagonals of the mainly rectangular aperture. In the case in which the gauze electrode consists of a perforated plate, the holes are provided in rows which extend approximately in the direction of the diagonals of the mainly rectangular aperture of the ring.
As is shown in FIG. 4, the parts of the sides 8 and 9 projecting inwardly may be bent out of the plane of the ring so that they slightly press on the gauze 4 and thus intensify the damping effect. It has been found that the damping of a ring formed according to the invention is approximately 20 times more effective than in the case in which a ring 7 is used having a rectangular hole with straight sides.
Although two particular embodiments of the invention have been described, other shapes for the aperture of the ring 7 may be used without departing from the scope of this invention. For example, a rectangle may be used having two straight and two oppositely located curved sides, or the corners may not be rounded off, in which case a cushion-shaped aperture is formedv The use of an aperture having more than 4 sides is more unfavourable according as the number of sides increases, since the circumference of the aperture increasingly approaches the circle, which is unfavourable with respect to the occurrence of vibrations.
Besides for camera tubes, the invention is also of importance for other cathode-ray tubes, for example, oscillograph tubes, and the like.
What is claimed is:
l. In a cathode-ray tube having a target electrode at one end of an envelope and a gauze electrode spaced from said target electrode, the improvement comprising at least one annular member spaced from said target for supporting said gauze electrode with reduced microphonic interference, said annular member having an inner edge enclosing a substantially rectangular aperture having at least two oppositely located curved sides, said gauze electrode comprising wires extending substantially parallel to the diagonals of said rectangular apertures.
2. A gauze electrode as claimed in claim 1, wherein the rectangular aperture has rounded corners.
3. A gauze electrode as claimed in claim 1, wherein the curved sides are convex towards the center of the aperture.
4. A gauze electrode as claimed in claim 3, wherein the convex shaped parts of the supporting ring are bent out of the plane of the ring in the direction of the gauze.
5. A gauze electrode as claimed in claim 4, wherein the radius of the curved sides is approximately equal to the radius of the outer edge of the supporting ring.

Claims (5)

1. In a cathode-ray tube having a target electrode at one end of an envelope and a gauze electrode spaced from said target electrode, the improvement comprising at least one annular member spaced from said target for supporting said gauze electrode with reduced microphonic interference, said annular member having an inner edge enclosing a substantially rectangular aperture having at least two oppositely located curved sides, said gauze electrode comprising wires extending substantially parallel to the diagonals of said rectangular apertures.
2. A gauze electrode as claimed in claim 1, wherein the rectangular aperture has rounded corners.
3. A gauze electrode as claimed in claim 1, wherein the curved sides are convex towards the center of the aperture.
4. A gauze electrode as claimed in claim 3, wherein the convex shaped parts of the supporting ring are bent out of the plane of the ring in the direction of the gauze.
5. A gauze electrode as claimed in claim 4, wherein the radius of the curved sides is approximately equal to the radius of the outer edge of the supporting ring.
US404340A 1972-10-27 1973-10-09 Gauze electrode for a cathode-ray tube Expired - Lifetime US3860851A (en)

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NL7214547A NL7214547A (en) 1972-10-27 1972-10-27

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US (1) US3860851A (en)
JP (2) JPS4977528A (en)
AR (1) AR195746A1 (en)
CA (1) CA991241A (en)
DE (1) DE2350727C3 (en)
FR (1) FR2204881B1 (en)
GB (1) GB1424250A (en)
IT (1) IT996882B (en)
NL (1) NL7214547A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4323814A (en) * 1980-05-16 1982-04-06 Rca Corporation Mesh assembly having reduced microphonics for a pick-up tube
US4347459A (en) * 1980-10-31 1982-08-31 Rca Corporation Mesh assembly having reduced microphonics for a pick-up tube
US4678962A (en) * 1984-11-07 1987-07-07 Sony Corporation Image pickup tube

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5616759Y2 (en) * 1975-11-18 1981-04-18
JPS61110943A (en) * 1984-11-06 1986-05-29 Matsushita Electronics Corp Pickup tube

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3287585A (en) * 1963-03-15 1966-11-22 Westinghouse Electric Corp Target electrode assembly for an electron discharge device

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL245593A (en) * 1958-11-21
GB1014376A (en) * 1963-11-13 1965-12-22 English Electric Valve Co Ltd Improvements in or relating to television and like camera cathode ray tubes
FR1526976A (en) * 1966-01-19 1968-05-31 English Electric Valve Co Ltd Cathode ray tubes for television cameras and the like

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3287585A (en) * 1963-03-15 1966-11-22 Westinghouse Electric Corp Target electrode assembly for an electron discharge device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4323814A (en) * 1980-05-16 1982-04-06 Rca Corporation Mesh assembly having reduced microphonics for a pick-up tube
US4347459A (en) * 1980-10-31 1982-08-31 Rca Corporation Mesh assembly having reduced microphonics for a pick-up tube
US4678962A (en) * 1984-11-07 1987-07-07 Sony Corporation Image pickup tube

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FR2204881B1 (en) 1979-04-13
JPS5326901Y2 (en) 1978-07-08
JPS4977528A (en) 1974-07-26
AU6180173A (en) 1975-05-01
DE2350727C3 (en) 1979-02-08
JPS5331928U (en) 1978-03-18
IT996882B (en) 1975-12-10
GB1424250A (en) 1976-02-11
AR195746A1 (en) 1973-10-31
DE2350727B2 (en) 1978-06-08
CA991241A (en) 1976-06-15
NL7214547A (en) 1974-05-01
FR2204881A1 (en) 1974-05-24
DE2350727A1 (en) 1974-05-02

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