US2822494A - Electron beam-tuning-indication tube - Google Patents

Electron beam-tuning-indication tube Download PDF

Info

Publication number
US2822494A
US2822494A US320166A US32016652A US2822494A US 2822494 A US2822494 A US 2822494A US 320166 A US320166 A US 320166A US 32016652 A US32016652 A US 32016652A US 2822494 A US2822494 A US 2822494A
Authority
US
United States
Prior art keywords
screen
cathode
shape
tuning
luminescent
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US320166A
Other languages
English (en)
Inventor
Stietzel Horst Edgar Heinrich
Siebenberg Alexander Han Adolf
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Philips Corp
North American Philips Co Inc
Original Assignee
US Philips Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US2822494A publication Critical patent/US2822494A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/12—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen
    • H01J31/14—Magic-eye or analogous tuning indicators

Definitions

  • the invention relates to a cathode-ray tube for tuning indication, having shadow angles or the like controlled by deflection rods and, if desired, an amplifying system housed in the same bulb.
  • tuning indicators have been known for a long time and efiorts have been made to construct these tubes in order to obtain an optimum distinctness of indication or an optimum sensitivity, in a manner such that in the event of complete control they produce a maximum shadow angle.
  • a counter-electrode or counter-electrodes preferably being at the potential of the luminescent screen, in the proximity of the cathode in a manner such that a strong and extensive field is produced between the cathode and the counter-electrode and between the deflection electrode and counter-electrode.
  • This construction has a limitation in that these counterelectrodes themselves project shadow sectors onto the screen, these sectors having a constant width, so that the useful screen surface is reduced. Efiorts have been made to obviate this limitation by arranging the cathode with the associated electrodes eccentrically within the tube or to the luminescent screen. Thus, however, the second shadow sector produced in the case of concentrical arrangement is lost; this sector contributed efiectively to enhance the tuning indication. Moreover, also for structural reasons this arrangement is not very favourable.
  • the invention obviates this disadvantage and consists in that the equipotential lines of the electric field between the screen and the cathode are made substantialy elliptical in form by a shaping of the parts of the system at the potential of the screen, without introducing additional electrodes.
  • An efiicient embodiment of the tuning indicator according to the invention consists in that the elliptical shape of the equipotential lines is obtained by means of a rotational-unsymmetrical shape of the screen, the circumference of which varies periodically. In other words, the shape of the screen is not a surface of revolution.
  • a funnel-shaped luminescent screen the cross-sectional area of which is oval and which has angles of different slopes, which are flatter in the direction of the long axis, on which the deflection rods are also located, and which extend more steeply in the direction of the short axis.
  • a further advantageous embodiment consists in that the funnel-shaped luminescent screen is substantially circular and has lines of inclination which extend with uniform steepness in the direction through the control-rods and extend first flatly towards the inside then gradually more steeply in the direction at right angles thereto.
  • the light distribution of the luminescent surface may lack uniformity.
  • the funnel-shaped screen has a circural cross-sectional area and lines of inclination which extend first steeply towards the inner side in the direction through the control-rods and then extend gradually more flatly, but exhibit a constant slope in the direction at right angles thereto.
  • the elliptical shape of the equipotential lines may be obtained not only by a corresponding shape of the luminescent screen, but also by suitable shape of the cathode hood, which has to screen principally the light emanating from the incandescent cathode and is usually at the potential of the screen. As an alternative, these two measures may be combined, so that they support one another. To this end, it is desirable to shape the cathode hood, which is at the potential of the screen, in the form of a cup having a short, substantially cylindrical wall,
  • Fig. 8 shows a cathode hood having recesses in accordance with the invention.
  • Figs. 1 and 2 show the equipotential lines of the electric field between the cathode 2, which is surrounded by a grid 1, and the luminescent screen 3 in a tuning indicator of conventional construction; the control-rods are designated by 4. If the control-rods are, at cathode potential, the form of the equipotential lines is that shown in Fig. 1. If the rods are substantially at the potential of the luminescent screen, the shape of the equipotential lines shown in Fig. 2 is obtained. The electrons emanating from the cathode 2 first follow the lines at right angles to the equipotential lines and then extend straight on.
  • Figs. 3 and. 4 for an indicator tube according to the invention; the same reference numerals are used in these figures. It is assumed in the first place that the equipotential lines have the elliptical shape shown in Fig. 3 when the control-rods 4 are at cathode potential, though the means for obtaining this form are not shown. The deformation of the equipotential lines for the case in which the control-electrodes 4 are substantially at the potential of the luminescent screen is shown in Fig. 4. A comparison between Figs. 1 and 3 shows that, owing to the elliptical shape of the equipotential lines, a materially larger shadow angle is obtained.
  • a luminescent screen as shown in Fig. 5.
  • the upper wider portion of the luminescent screen 3 is oval in shape, the aperture at the bottom of this funnel-shaped screen being, as usual, circular.
  • the two control-rods 4 the cathode 2 being, of course, at the center and coaxially within the screen 3.
  • the associated lateral views, below and to the right of the plan view, show that the angles of inclination of this funnel have different steepnesses; they are flatter in the direction of the long axis of the ellipse, and steeper in the direction of the short axis.
  • the lateral views shown are almost identical to cross-sectional views through the screen along the major and minor axes of the oval screen 3. These cross-sectional views would correspond to the intersections of the screen with orthogonal planes having the screen axis as their line of intersection. As will be noted, these two intersections, i. e., the side views shown in the drawing,
  • FIG. 6 A further embodiment of such a luminescent screen is shown in Fig. 6.
  • the luminescent screen 3 is, in this case, circular, so that the spectator observes the conventional circular shape and, moreover, the circular sectional area of the bulb is satisfactorily utilized.
  • the angles of inclination of the funnel are slightly shortened in the direction of the axis x--x, as is evident from the associated later or side view. That is, these side portions of the screen are concave instead of straight.
  • the angle of inclination is straight, as is evident from the associated lateral view. With respect to the profile of inclination, a uniform transition exists between these two axes.
  • FIG. 7 A further possible shape of the luminescent screen is shown in Fig. 7.
  • the screen is circular, but the lines of inclination are straight in the direction of the axis x-x, and in the direction of the axis y-y, the steepness varies in a sense contrary to that of the embodiment described in Fig. 6. That is, the side portions are convex instead of concave.
  • the shape of the lines of inclination is evident from the associated lateral views.
  • an elliptical field is obtainable by using luminescent screens having the common feature that use is made of rotational-unsymmetrical bodies.
  • the cathode hood which primarily serves to screen the light emanating from the cathode, may also be utilized to obtain an electric field of this shape.
  • This hood usually is at the potential of the luminescent screen, and, since in comparison with the conventional electrode system, this hood has appreciable dimensions, it exerts a marked influence on the shape of the electric field.
  • a suitable embodiment of such a hood is shown in Fig. 8.
  • This hood comprises a cylindrical Wall 5 of comparatively small height, closed at the top by a slightly arcuate bottom 6 and supported by stay wires 7.
  • the lower edge of the wall 5 is provided with recesses 8 at two areas diametrically opposite one another; these recesses produce an elliptical deformation of the electric field. It is advantageous to use a cathode hood as shown in Fig. 8 in conjunction with a luminescent screen as shown in any of the preceding embodiments, in order to have the effects of the two parts support one another.
  • the difierent cross-sectional views of the screen indicate a screen construction that distorts what was primarily a field with circular equipotential lines to one with mainly elliptical equipotential lines, which, as illustrated in Figs. 3 and 4, results in a wider shadow region with the minimum signal.
  • a cathode-ray tuning indicator tube comprising a hollow, luminescent screen, a cathode arranged centrally and coaxially within the luminescent screen, and means including deflection members disposed between the cathode and screen for controlling, by its potential, the extent of fluorescence of the screen and arranged to provide two opposed fluorescent areas on the screen, the intersections of orthogonal planes, having the axis of the screen as their line of intersection, with the screen being different, whereby said screen has a shape different from a surface of revolution and'the equipotential lines of the electric field t cross-section with a long axis in one direction and a short axis at right angles thereto, a cathode arranged centrally and coaxially within the luminescent screen, and means including deflection members disposed along the long axis of the oval and between the cathode and screen for controlling, by its potential, the extent of fluorescence of the screen and arranged to provide two opposed fluorescent areas on the screen, the intersections of
  • a cathode-ray tuning indicator tube comprising a funnel-like, hollow, luminescent screen, a cathode arranged centrally and coaxially within the luminescent screen, and means including deflection members disposed between the cathode and screen for controlling, by its potential, the extent of fluorescence of the screen and arranged to provide two opposed fluorescent areas on the screen, said funnel-like screen having concave portions on opposed side Walls so that the intersections of orthogonal planes, having the axis of the screen as their line of intersection, with the screen are different, whereby said screen has a shape difierent from a surface of revolution and the equipotential lines of the electric field established between cathode and screen when a potential difference is applied therebetween are strongly elliptical in shape.
  • a cathode-ray tuning indicator tube comprising a funnellike, hollow, luminescent screen, a cathode arranged centrally and coaxially within the luminescent screen, and means including deflection members disposed between the cathode and screen for controlling, by its potential, the extent of fluorescence of the screen and arranged to provide two opposed fluorescent areas on the screen, said funnel-like screen having convex portions on opposed side walls so that the intersections or orthogonal planes, having the axis of the screen as their line of intersection, with the screen are different, whereby said screen has a shape ditferent from a surface of revolution and the equipotential lines of the electric field established between cathode and screen when a potential difference is applied therebetween are strongly elliptical in shape.

Landscapes

  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
US320166A 1952-03-20 1952-11-13 Electron beam-tuning-indication tube Expired - Lifetime US2822494A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE313049X 1952-03-20

Publications (1)

Publication Number Publication Date
US2822494A true US2822494A (en) 1958-02-04

Family

ID=6138349

Family Applications (1)

Application Number Title Priority Date Filing Date
US320166A Expired - Lifetime US2822494A (en) 1952-03-20 1952-11-13 Electron beam-tuning-indication tube

Country Status (6)

Country Link
US (1) US2822494A (is")
BE (1) BE518559A (is")
CH (1) CH313049A (is")
FR (1) FR1073069A (is")
GB (1) GB747492A (is")
IT (1) IT500096A (is")

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2051189A (en) * 1935-06-27 1936-08-18 Rca Corp Tuning indicator tube
US2105818A (en) * 1937-06-22 1938-01-18 Rogers Radio Tubes Ltd Voltage indicating electron discharge tube
US2243034A (en) * 1937-06-03 1941-05-20 Hygrade Sylvania Corp Fluorescent indicating device
US2321855A (en) * 1940-01-17 1943-06-15 Gen Motors Corp Indicator
US2394857A (en) * 1940-07-23 1946-02-12 Rca Corp Electron ray indicating device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2051189A (en) * 1935-06-27 1936-08-18 Rca Corp Tuning indicator tube
US2243034A (en) * 1937-06-03 1941-05-20 Hygrade Sylvania Corp Fluorescent indicating device
US2105818A (en) * 1937-06-22 1938-01-18 Rogers Radio Tubes Ltd Voltage indicating electron discharge tube
US2321855A (en) * 1940-01-17 1943-06-15 Gen Motors Corp Indicator
US2394857A (en) * 1940-07-23 1946-02-12 Rca Corp Electron ray indicating device
US2749465A (en) * 1940-07-23 1956-06-05 Int Standard Electric Corp Visual indicating device for electric voltages

Also Published As

Publication number Publication date
IT500096A (is")
FR1073069A (fr) 1954-09-20
CH313049A (de) 1956-03-15
BE518559A (is")
GB747492A (en) 1956-04-04

Similar Documents

Publication Publication Date Title
US2749465A (en) Visual indicating device for electric voltages
US2170663A (en) Electron discharge device
US2822494A (en) Electron beam-tuning-indication tube
GB977892A (en) Method of and apparatus for manufacturing a colour cathode ray tube
US2813224A (en) Color television picture tube
US3524094A (en) Wide deflection angle cathode-ray tube with a lens for focussing the electron-beam at an elongate spot on a screen and an astigmatic correcting lens
US2591521A (en) Cathode-ray tube and method of manufacturing such tubes
US2206387A (en) Electronic device
US2827592A (en) Post-acceleration cathode ray tube
GB1328080A (en) Cathode-ray tube with deflection amplification and post deflection acceleration
US2206954A (en) Electron discharge device
US2273800A (en) Fluorescent type indicator tube
US2340631A (en) Secondary electron amplifier
US2103022A (en) Gaseous discharge tube
GB1311406A (en) High contrast display for electron beam scaner
US2311672A (en) Electron discharge tube with fluorescent screen
US2802128A (en) Tuning indicator valve
US2051189A (en) Tuning indicator tube
US2183398A (en) Cathode ray tube
US2297429A (en) Cathode ray tube
US2736834A (en) Electron discharge tube comprising a luminescent screen
US2236860A (en) Electron discharge device
US2829294A (en) Cathode ray tuning indicator tube
US2973446A (en) Electric discharge tube
US2845563A (en) Beam generating system