JPS6161350A - Meshless type cathode-ray tube - Google Patents

Abstract

PURPOSE:To amend pattern distortion and deflection rate linear tendency, by forming an electron lens together with a cylindrical electrode of a flat box type which has a specific cavity on the end of the target side, and an electric field of a latter part acceleration electrode. CONSTITUTION:A meshless type cathode-ray tube used for an oscilloscope etc. is composed including an electron gun 7, a deflection system 10, a cylindrical electrode 17, a latter part acceleration electrode 12, and a target 13. The cylindrical electrode 17 is formed to have a quadrilateral in section with 4 faces 18-21, making the ends 22 of the target 13 side faces 19 and 20 concave, preparing concave portions 25 and 26 on both sides 23 and 24, and moreover, making the ends 27 of the target 13 side faces 19 and 21 concave. Therefore, a deflection expanding lens 11 can be available by functioning a high level electric field of the latter part acceleration electrode 12 to the cylindrical electrode 17, so that the pattern distortion and deflection rate linear tendency can be amended by combining those concaves, as well as the system is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a mesh-less m cathode ray tube which is used in oscilloscopes, storage tubes, etc. and has a structure in which a useless mesh electrode is removed.

Conventional technology and its problems Does the conventional general post-acceleration cathode ray tube use an electron beam emitted from an electron gun? After being deflected vertically or horizontally, the spot is increased in brightness on a luminescent screen by being accelerated by a subsequent accelerating electric field formed by a flat mesh or a curved mesh and a subsequent accelerating electrode on the inner wall of the pulp. It's structured so that you can get it. However, cathode ray tubes of this type have the disadvantage that the spot resolution and electron gun efficiency deteriorate due to the mesh, and that halation occurs on the screen surface due to secondary electrons hitting the mesh. In order to solve this kind of drawback, a cathode ray tube without a mesh was developed,
There is a mesh electrode which is a combination of two quadrupole lenses and a hemispherical electrode as disclosed in the above publication. However, this type of cathode ray tube has a large deflection angle, so the screen surface The disadvantage is that blurring occurs at the edges and the spot uniformity deteriorates, and in addition, two additional electrodes must be placed to correct pattern distortion (・and-・
There were some drawbacks. Also, in Japanese Patent Application Laid-open No. 53-87161, there is a four-pole lens that meshes with each other. Two cylindrical electrode members to be taught? However, this type of cathode ray tube has the drawback that the shape of the meshing part is complicated and difficult to manufacture, and the potential difference of 20 kV between the two nodal electrodes has been disclosed. However, it had the disadvantage that it was difficult to maintain the withstand voltage between both electrodes.Furthermore, it was disclosed in Japanese Patent Publication No. 57-25942 as a cathode ray tube without mesh electrodes. However, in this type of cathode ray tube, the lens is 10.6 cm in total length, 6.3 cm in width, and 2.5 cm in height, which is much larger than the dome mesh type. Therefore, the drawback is that conventional glass pulp cannot be used, and when used in a rear-stage muzzle-speed cathode ray tube, the output electrode of the lens is electrically connected to the screen potential, so it has to withstand voltage with other electrodes. ?The disadvantage was that it was difficult to maintain.

Furthermore, Japanese Patent Publication No. 58-8543 and Japanese Unexamined Patent Application Publication No. 55-53858 related to the present applicant include slits? A box-shaped lens is disclosed. This consists of a lens generated based on a box divided into three or two parts, and a lens generated based on a slit on the target side of this box (1).
Is the display with less vertical blur due to interaction with these two lenses? This made it possible. However, in the 3-part blade type, the middle electrode of the 3-part box-shaped lens has a convex or concave shape in both directions of the cand and the target.
Each '1! Assembly accuracy between poles? If it is difficult to improve (
・There are some drawbacks. Also, both the 3-part and 2-part methods,
In order to prevent the subsequent accelerating electric field from entering the approximately 1 mm gap provided between each electrode for insulation, it was necessary to surround it with a shield electrode and the housing of the first lance, which was inconvenient. Another slit? Because of this, the configuration became complicated.

Furthermore, JP-A-59-134531 discloses a meshless type scanning magnifying lens (hereinafter referred to as MSE lens). This MSE lens consists of a flot lens, a fairly thick cylinder, a laser-cut electrode, and the like. It consisted of a cylindrical high-voltage electrode surrounding it and an aperture lens on the screen side, making it complex both in terms of structure and production.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a meshless cathode ray tube that is simple in structure, easy to manufacture, and inexpensive. It is about providing.

problem? Means to solve the above purpose? What is the embodiment of the menschless cathode ray tube according to the present invention? What is the code of the drawing shown? To explain with reference to the electron gun (7) and the electron beam emitted from the electron gun (7)? a deflection system (tO) that deflects in a first direction and a second direction perpendicular to the first direction;
At least one back-stage electrode provided after Ω, a target (L31) that collides the electron beam emitted from the electron gun (7), and an electron disposed near the back-stage electrode. In a menschless cathode ray tube comprising at least a lens ((1)), the electron lens (L
IJ consists of a cylindrical electrode αη, and the first, second, third and fourth surfaces α81 are arranged so that the cylindrical electrode aη has a quadrilateral cross-section. and the centers of the cross sections thereof coincide with and face the pipe 5iC (
2 (l extends in the 20th direction 9 , the opposing second and fourth surface concave circles extend in the first direction, and the cylindrical electrode (lη of the opposing first and fourth 30th
The end f221 on the target side of bet (2) is formed in a concave shape, and both ends r23c of the first and third surfaces ua+C20+ near the end cap on the target side are formed. A small concave portion C9 (to) is provided, and the ends □□□ on the target side of the opposing second and 40th surfaces (lcj2) J of the cylindrical electrode α are each formed in a concave shape, and the cylindrical shaped electrode a
Depending on the relationship between the potential of η and the potential of the subsequent electrode u4,
The traveling direction of the electron beam deflected in the tenth direction by the deflection system Uω on the nodal electrode structure η? An action of inverting and enlarging the deflection of the electron beam and enlarging the deflection of the electron beam swung in the second direction by the deflection system? The present invention is characterized in that a potential applying means is provided for applying a potential to the cylindrical electrode and the latter stage electrode (121) so as to generate the cylindrical electrode.

Function: If the planar electrodes are arranged as in the above invention, the subsequent electrodes (
An electron lens effect occurs when the electric field enters the inside of the cylindrical electrode (17). Then, a cylindrical electrode (L
7), the ends of the first and 30th sides on the target side are concave, and the ends of the first and third sides (both ends c of the 181st side) are concave.
! 31 (to) is provided with a concave portion (c) 3Q, and the target side end of the second and "i4 surface 1t211 is concave, so the combination of these makes the pattern distortion and deflection straightness relatively low. Easily improved.

Example Next, Figure M1 to Figure 9? With reference to this, a cathode ray tube (hereinafter referred to as CRT) of an oscilloscope according to an embodiment of the present invention will be described.

The CRT shown in FIG.
Cathode (21 and 1st grid (31 and 2nd grid (
4), an electron gun (7j) consisting of a first anode +5j and a second anode +67.

A pair of vertical deflection plates (81) as a first deflection system deflects the electron beam emitted from the electron gun (77) in the first direction (vertical direction) and directs the electron beam in the second direction (horizontal direction). A pair of horizontal deflection plates (as a second deflection system)
9), and a nodal electron lens for deflection magnification (llll) in sequence, and furthermore, the outer wall has a rear-stage accelerating electrode α4 and a target 113 made of a conductive coating provided on the inner surface of J. Among them, the electron gun (7), the deflection thread σ
The Q% post-acceleration electrode Q4 and the target tta+ are common parts, and the cylindrical electron lens Uυ is a novel part according to the present invention. In addition, the target housing unit consists of a face plate (141), a source body layer, and a conductive layer 4 connected to the rear acceleration electrode (j+-/light body screen).

The electronic lens aυ according to the present invention has one convex electrode α force? The elongated electrode U is arranged so that the electric field of the subsequent acceleration electrode U acts on its end on the target side.

In order to operate the CRT configured as described above, for example, -1.5 kV to the cathode (2), -1600 to -1500 V to the first grid, and -1600 to -1500 V to the i2 grid (2).
OV to 4, focus voltage adjusted to about -1ooov to the first anode (5), -200 to the second anode (6).
V~+200V, extreme rear acceleration (121K 17.5
kV, cylindrical component of the electron lens mountain 1! Ov to Gokumata η
is supplied. Then, the electron beam emitted from the cathode (2J) is controlled in beam quantity by W, 1 grid (3),
The second grid (4) then accelerates the second grid (4). grid(
4) and the first and second anodes are focused by a potential lens consisting of +5J and 16J, and sent into the deflection system. When the electron beam is swung in a first direction (vertical direction) by the deflection thread (10), the traveling direction of this beam is reversed by the electron lens υ, and the deflection in the first direction is expanded. The electron beam in the deflection system α0Ivc is the 20th
When a photograph is taken in a direction (horizontal direction), the electron lens ulJK is used to deflect and enlarge the image in the 20th direction.

As is clear from FIGS. 2 to 5, the cylindrical electrode fin according to the present invention has the following features: 1. The second, third and fourth surfaces (Ls) are formed into a rectangular box shape with a flat cross section.

Note that, as shown in FIG. 5, a pair of long sides of the resulting rectangular cross section coincide with the second direction (horizontal direction) by the first +7th) surface αe of the cylindrical electrode αη and the 30th surface {circle over (30)} facing this, as shown in FIG. A pair of short sides of a rectangular cross section created by the second surface part and the 40th part c211 opposing this part are in the first direction (vertical direction)
The cylindrical pole αη is placed on the tube axis so that it coincides with the cylindrical shape.

The opposing first and third surfaces a to 4 of the cylindrical electrode (17) have the same shape, and the end of each target side has a shape (circle, ellipse, or It is formed in a concave shape like a part of a hyperbola or a combination thereof, and is slightly arched (concave) in the cathode direction.
Both ends (23 (2) extending along the tube axis of α814 are each provided with a recess (c) @.
Concave portions C514 shaped like a part of a circle, an ellipse, a hyperbola, or a combination thereof are provided near both ends of the target side ends (2z) of the third surface (2Cj).

The ends of the opposing second and fourth surface hazes Qυ of the cylindrical electrode αη on the target side are formed in a concave shape like a circle, an ellipse, a part of a hyperbola, or a combination thereof, and are depressed toward the cathode. .

In this embodiment, the end is formed into a concave shape having a radius of curvature R+, and the width of this concave portion is set to W3. Curvature of radius Rt on both sides of this width Ws? A concave portion (25Ice) with a radius R is provided so that the concave portion (25Ice) extends in the 20th direction (horizontal direction), and after the narrowest width W2 is obtained, the curvature of the radius R is width W1
has been returned to. f 2nd and 40th (t! I Zl
The target side end @ of j is formed into a concave shape having a radius of curvature R3.

Display screen 8cm high and 10cm wide? CRT with
What are the geometric dimensions of the cylindrical electrode α? To illustrate, in the vertical direction (first direction), the second and fortieth sides (one
The height of 91121+ is approximately 22 mm, the width in the horizontal direction (second direction), that is, the width W1 of 201 is fJ 30 mm, and the first and third surfaces (1at(20+
The length Dl from the end of the beam to the most protruding point of the end on the target side is approximately 40 mm.
Menzumi! 11 (The length from the 2V beam entrance end to the most protruding point of the end on the target side is approximately 23 m.
m, the radius of curvature R1 at the end @ is approximately 20 mm, the width W of the R1 portion is approximately 24 mm, the radius R2 is l'g 3 mm, the radius R8 is approximately 4 mm, the radius melon is approximately 3 mm, @D at the recess □□□4 , is about 8 mm, and the opposing recess r25Icle
The tin W2 of IN is about 16 mm, and the radius R1 is about 12 mm. Note that each part of the electrode (1 force) is made of non-magnetic stainless steel with a thickness of 0.5 mm.
0 and α814 (1 has exactly the same shape and is arranged opposite to each other.

Similarly, the second and fortieth units (1!lit I211) have exactly the same shape and are arranged opposite to each other.

Figures 6 and 7 on the arrow? See the trajectory of an electron beam in an electron lens cone? explain. Now, connect the cylindrical electrode (17) to, for example, the OV1 latter-stage acceleration electrode (for example, 17.5 kV to 12+).
If i is applied, the latter accelerating electrode α4 is placed inside the cylindrical electrode housing η.
An electron lens is formed at the end of the cylindrical electrode αη on the target side, that is, near the exit, by the intrusion of a high electric field based on . In the -1'li cross section of the third frame shown in FIG. 6, equipotential lines f3G are distributed so that a convex lens effect occurs. As a result, the electron beam 6υ or +X 321 &'! is swung in the first direction (vertical direction). ,,Convex lens action? The direction of travel is reversed, the beam is deflected and expanded in the tenth direction, and reaches the target u.

In the cross section of the fourth factor shown in FIG.

As a result, the electron beam beam 4 or r3ω swung in the 20th direction (horizontal direction) does not proceed as shown by the dotted line, but proceeds as shown by the solid line, is deflected and expanded in the second direction, and hits the target [31]. Arrive.

By the way, when configuring the electron lens (11J) using the cylindrical electrode α7), the biggest problems are pattern distortion, polarization straightness, and spot uniformity in the first direction (vertical direction).

Does this example have the above problem? To solve the problem, a concave end with a radius R8 and a concave part □□□Hasumi on the first and 30th surfaces αgI4? Further, concave ends with a radius R11 were provided on the second and fourth surface corners. First, to explain the relationship between pattern distortion and the cylindrical electrode αη, the pattern distortion in the upper and lower portions of the horizontal bright line on the screen is mainly defined by the magnitude of half @R1. For example, if R8 is about 20 mm and the horizontal emission line is almost straight, it is thicker than R+Y20mm (then, as shown by the solid line r, 3D in Fig. 8, a bin cushion distortion of the horizontal emission line occurs, and R+re is, for example, 25 mm%. 30mm
If the value is gradually increased, the bin cushion distortion of the horizontal emission line will gradually increase. Conversely, if the RIl is smaller than 20 mm, barrel distortion will occur as shown by the dotted line 6z. This is R
Other than t? Fixed, R1 only? Confirmed by experiment with changes.

Also, if the horizontal bright line is undulating, the end may be made into an appropriate quadratic curve (circle, ellipse, hyperbola, etc.), a compound curve of these, or a concave compound curve including a straight line.・.

Pattern distortion in the direction of the vertical bright line on the screen is largely influenced by vAW2 and radius R.

Please reduce the width W, for example from 16mm to 12mm (
The penetration of the high electric field from the second direction is strengthened, the sensitivity in the horizontal direction is improved, and the vertical bright line tends to have a bottle cushion distortion. Conversely, if the width W2 is increased, the barrel tends to become distorted. Also, if the vertical bright line has an appropriate radius R6, for example, the solid line in Fig. 9 (as shown in 33),
5 end gr) Appropriate 2 missing pieces + 1 IC circle, ellipse, hyperbola, etc. or a compound curve or straight line of these? Compound curve including? For example, is it a convex curve on the canard side? You should just make it...

As shown by the broken line in FIG. 11, if pattern distortion is generated as shown in FIG.
All you have to do is correct the shape of . In addition, if the edge is approximated as a circle with radius R1 as shown by the broken line in Figure 1O, resulting in a pattern distortion in which the horizontal bright line curves 5 times, vc will be, for example, as shown in the solid line in Figure 10. The shape of the? Oke-shocho is fine.

Next, we will discuss deflection directness. When the width difference is constant, the deflection straightness in the first direction (vertical direction) is determined by the height H,
It is determined by the rear acceleration ratio. Make H1 smaller (・(
, the deflection straightness in the direction of if becomes positive (this is known through experiments).Also, by reducing the rear acceleration ratio from, for example, 12 to 8...(Similarly, in the glass direction) Therefore, in this embodiment, a method is needed to increase Hl and the rear acceleration ratio by the same amount.Also, in the second direction (
The straightness of deflection in the horizontal direction is mainly determined by the degree of curvature of the end face support. Radius R4, for example 12mm to 18mmV
When C is increased, the depression due to R1 in the end face becomes shallower, and therefore the penetration of the high electric field is reduced.
The deflection straightness in direction 2 moves in the i-minus direction. Also,
Is HJ the effective area on the screen in the 10th direction? stipulate,
For example, when the distance between the rM-shaped electrode qη and the target is constant, the larger the distance, the larger the effective area in the first direction (vertical direction).

By making W2 smaller, that is, the depth of the recesses on the opposing 10th and 30th surfaces (a) is too large (by doing so, the sensitivity in the second direction is improved.

! In addition, there is a problem with the spot uniformity in the 10th direction (vertical direction) (normally, the spots are lined from the center to both the upper and lower ends (the vertical width of the spot becomes thicker), but the beam passing along the tube axis has a strong convexity. (Focusing lens effect, which is weak for electron beams taken in the vertical direction by the deflection system, occurs from the equipotential surface shown in FIG. 6, resulting in good vertical spot uniformity.

Misfire F! J4 is not limited to the above-mentioned embodiments (
For example, the following modifications are possible.

As shown in FIG.
Pages 1 to 40 ((1) 9 to 40) are qualitatively the same as those shown in the figure.
t211 Power generated, Fig. 2 ~ g51S4 (7) Cylindrical 1!
It is possible to obtain the same effects and effects as (l?).

03) As shown in Figure 13 (, 1st and 3rd face shouts
may be formed to widen toward the target.

Further, the second and fourth surfaces α9F2 may also be widened towards the target. Further, the cross section of the cylindrical electrode μ force may be square or may be a vertically long rectangle.

C) As shown in Figure 14, a 3m quadrupole lens t411 (
The present invention is also applicable to CRTs having a format of 421. In this case, the beam propagation direction 1r of the lens (411): For example, O to -300 V is applied to the @pole in the second direction (left and right) with respect to the beam traveling direction 1r of the lens (411).

For example, the electrodes in the first direction (up and down) of the lens circle are
V, I/ins (for example +300V to the left stone electrode of 4
Electrode traps on the upper and lower sides of the lens 44, for example, 0 to -300V; electrodes on the left and right sides of the lens, for example, -100 to -200V;
For example, Ovr is applied to the upper and lower electrodes of the lens (1) 3. Is it the same effect as the example even if I do this? You can get it. 'a) As shown in Figure 15, a quadrupole lens t44 is placed between the vertical deflection plate (8) and the horizontal deflection plate (91).
1', and based on the traveling direction of the electron beam, the electrode on the left stone is set to -100 to -200V, for example.
Up and down! For example, OVY may be applied to luck. Even if a#: is used in this way, the same effects as in the embodiment can be obtained.

(El) The funnel part of the vacuum outer wall (1) surrounding the target-side opening sft of the cylindrical electrode housing η shown in Figure 16 is parallel to the tube axis, and is designed without K to easily obtain the required assembly accuracy. The performance of the CRT may be stabilized.

[F] As shown in FIG. 17, the post-acceleration pole (12a) provided on the inner surface of the vacuum outer wall (1) is electrically connected to the pole U4 and has a circular or quadrilateral cross section. 'l, and a cylindrical electrode (LT) can be installed in it.In this way, it becomes possible to stably install the cylindrical electrode housing that constitutes the electronic lens. Condition 1! Koshiki (12aJ
acts in the same way as the latter acceleration electrode U on the wall surface.

(G The R2 part in Figure 3 is chamfered to approximate a circle in relation to the rear acceleration pole 4, but it may be a different curve, or it may be a corner if withstand voltage is not an issue. Further, the R+, Ra, gourd, and horse parts may be variously modified to optimize pattern distortion and deflection straightness.

D Instead of an electrostatic focusing electron gun, an electromagnetic focusing electron gun may be used. Another deflection system? An electromagnetic deflection configuration may also be used.

(I) Is there a cylindrical electrode effect due to the collimation electrode of the storage tube? It is possible to cause Therefore, the invention? It can also be applied to storage tubes, etc.

Effects of the Invention As is clear from the above (according to the present invention, one cylindrical electrode is inserted between the deflection system and the target, and a high electric field is applied by the subsequent electrode to obtain an electron lens for deflection magnification. Therefore, the configuration of the CRT becomes simple, and the desired assembly speed can be easily obtained.It is also possible to reduce the cost of the CRT.
The concave shape of the target side end of the 1st and 1g30 faces and the 1st
And pattern distortion and deflection straightness due to the combination of the concave portions at both ends of the third side and the concave portions at the ends of the second and fourth surfaces on the target side? Since it improves, is this an improvement? It can be easily achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a CRTv according to an embodiment of the present invention,
2 is a perspective view schematically showing the CRT's cylindrical electrode in FIG. 1, FIG. 3 is a plan view of the cylindrical electrode in FIG. 2, and FIG.
Cylindrical shape 1 in the figure! Inside the pole side, Fig. 5 is a cross-sectional view of the cylindrical electrode in Fig. 3 taken along the line Y, and Fig. 6 is a cross-sectional view of the beam trajectory shown in Fig. 3.
- Is the cross-sectional view of the part corresponding to the ■ line, Figure 7, the beam trajectory?
The cross-sectional view of the part corresponding to the line ■-■ in Fig. 4 shown in Fig. 8 shows the pattern distortion of the horizontal bright line? Is the figure shown in Figure 9 an example of vertical bright line pattern distortion? 10 is a plan view showing a modification of the first and third surfaces, FIG. 11 is a side view showing a modification of the second and fourth surfaces, and FIG. 12 is a modification of the cylindrical electrode. A cross-sectional view showing an example, FIG. 13 is a modification of the cylindrical electrode? The perspective view, FIG. 14, FIG. 15, M2S diagram, and FIG. 17 are sectional views showing modified examples of the CRT. +7J ・'[Subgun, 1lQl...Deflection system, aυ...
・Electronic lens, (14... post-acceleration electrode, (13i・
...Target, wholesaler...cylindrical electrode, bet...Ml surface, ■...second surface, (201...third surface,...
・Fourth surface, @...target side edge, (c) G61・
...Concave portion, (27)...Target side end.

Claims (6)

[Claims] (1) An electron gun (7) and an electron beam emitted from the electron gun (7) in a first direction and a second direction perpendicular to the first direction.
a deflection system (10) that deflects in the direction of
0), a target (13) for impacting the electron beam emitted from the electron gun (7), and a target (13) provided at a stage subsequent to the electron gun (7);
In a meshless cathode ray tube comprising at least an electron lens (11) disposed near the electron lens (12), the electron lens (11) comprises a cylindrical electrode (17), and the cylindrical electrode (17) The first, second, third and fourth surfaces (18) (19) (20) are arranged so that the cross-sectional shape is quadrilateral.
) (21), the center of the cross section thereof coincides with the tube axis, and the opposing first and third surfaces (18) and (19) extend in the second direction, and the opposing second and third surfaces The fourth side (
19) (21) is arranged so as to extend in the first direction, and the end (22) on the target side of the opposing first and third surfaces (18) and (19) of the cylindrical electrode (17) are each formed in a concave shape, and both ends (
23) Concave portions (25) and (26) are provided in (24), respectively, and target-side ends (27) of the opposing second and fourth surfaces (19) and (21) of the cylindrical electrode (17) ) are formed in a concave shape, and depending on the relationship between the potential of the cylindrical electrode (17) and the potential of the latter electrode (12), the cylindrical electrode (17) is provided with the deflection system (10). Reversing the traveling direction of the electron beam swung in the first direction to produce an action of deflecting and enlarging it, and causing the deflection system to produce an action of deflecting and enlarging the electron beam swung in the second direction. The cylindrical electrode (17
) and the rear-stage electrode (12). (2) The meshless cathode ray tube according to claim 1, wherein the cylindrical electrode is formed in a flat box shape. (3) The meshless cathode ray tube according to claim 1, wherein the cylindrical electrode has a flat, substantially elliptical cross-sectional shape. (4) The meshless cathode ray tube according to claim 1, wherein the first and third surfaces are formed to widen toward the target. (5) The meshless cathode ray tube according to claim 1 or 2 or 3 or 4, wherein the second and fourth surfaces are formed to widen toward the target. . (6) The latter electrode includes an electrode provided on the tube wall and a cylindrical electrode arranged so as to surround the target-side end of the cylindrical electrode and electrically connected to the electrode provided on the tube wall. Claim 1 or 2 consists of an electrode.
The meshless cathode ray tube according to item 1 or 3 or 4 or 5.