JPH03116639A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To stably support an electron gun against external impacts so as to prevent tube properties from being varied by joining the cathode side end portion of a bar-shaped support body made of glass to the inner wall of a neck. CONSTITUTION:During assembly of an electron gun 1, the support structure of the electron gun is obtained by welding a projecting portion 18 and a neck 3 to each other using a glass bar-shaped body 17 on which a projecting portion 19 is formed and whose length is adjusted so that the projecting portion 19 is located on the welding portion of a stem 7 and a neck 3, simultaneously with welding of the stem 7 and the neck 3 to each other for sealing the electron gun. The electron gun being thus supported, the end portion side of the electron gun is stably held against external impacts by setting the spring constant of a valve spacer 18 to a proper value, and at the same time the cathode K side of the electron gun is firmly held by welding of the projecting portion 19 pro vided to the glass bar-shaped support body 17 and the neck 3 to each other and also by welding of a support portion 6 and a stem pin 6 so that the cathode K side is held by an extremely strong holding force; which should enhance properties of a cathode-ray tube.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a cathode ray tube, and more particularly to a cathode ray tube with stabilized support for an electron gun.

(Prior Art) Generally, in a cathode ray tube, an electron gun that emits an electron beam is disposed inside the neck of an envelope, and a deflection device attached to the outside of the envelope deflects the electron beam emitted from the electron gun. The structure is such that an image is displayed by being deflected by a magnetic field generated by the phosphor screen and horizontally and vertically scanning a phosphor screen formed on the inner surface of the face of the envelope. In particular, in color picture tubes, the electron gun is structured to emit three electron beams,
The three electron beams are formed to horizontally and vertically scan the phosphor screen via a shadow mask placed opposite the phosphor screen.

As an example of the above electron gun, an electron gun for a color picture tube is shown in FIG. This electron gun (1) includes a cathode (K), a grid (Gl) that controls electron emission from this cathode (K), (
G2) and this grid (Gl), a grid (G1) that focuses and accelerates the electron beam emitted through (G2).
It has a plurality of electrodes such as G3) to (OB), and these electrodes are fixed together by welding to a pair of glass rod-shaped supports (2) located along the side surfaces of the electron beam emitting end side. A compliance cup (C) is attached to the grid (G8).

And on the outer periphery of this convergence cup (C),
A plurality of valve spacers (5) are attached to press against an inner conductive film (4) applied to the inner surface of the cone portion of the envelope and extending onto the adjacent inner surface of the neck (3). This valve spacer (5) forms a conductor that guides the high voltage supplied from the anode terminal to the grid (G6) via the inner conductive film (4), and also holds the tip side of the electron gun (1). In order to improve the coaxiality between the electron gun (1) and the neck (3), a convergence cup (C) is usually used.
Welded at positions that divide the outer circumference equally. On the other hand, on the cathode (K) side, a glass rod-shaped support (2
) with a stem pin ( ) passing through the stem (7) in an airtight manner sealing the end of the neck (3).
8) is attached by welding.

By the way, not only general cathode ray tubes, but also automobiles, ships,
Cathode ray tubes installed in aircraft and the like are required to have strong vibration resistance. On the other hand, the valve spacer (5) that holds the tip side of the electron gun (1) needs to be inserted smoothly into the neck (3) when sealing the electron gun (1). A small spring constant is desired. On the other hand, in order to stably hold the cathode ray tube against external shocks, etc., it is preferable to use a cathode ray tube with a large spring constant. Therefore, in reality, the spring constant and the number of attachments are set so as to provide both insertion into the neck (3) of the electron gun (1) and shock resistance.

However, as mentioned above, the cathode (K) of the electron gun (1)
Since the sides are only fixed via stem pins (8) with relatively low mechanical strength, they are not held stably and are susceptible to bending due to external shocks applied to the cathode ray tube. As a result, the electron gun (1) is tilted due to the bending, etc., and the shape of the beam spot on the screen changes, causing a convergence shift, a color shift, etc., and there is a problem that the tube characteristics are deteriorated.

(Problems to be Solved by the Invention) As described above, the electron gun of a cathode ray tube is held by a plurality of valve spacers on its electron beam emitting end side, and the stem sealing the neck end on the cathode side is airtight. It is held by a penetrating stem pin with relatively low mechanical strength.

Therefore, external shocks applied to the cathode ray tube bend the stem pin, which has low mechanical strength, and as a result, the electron gun tilts and the shape of the beam spot on the screen changes. Especially in color picture tubes, convergence shift and There is a problem that color shift occurs.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to construct a cathode ray tube that stably supports an electron gun against external shocks and does not change the tube characteristics.

[Structure of the Invention] (Means for Solving the Problems) In a cathode ray tube in which an electron gun is disposed in the neck,
The cathode side end of a glass rod-shaped body that integrally supports the plurality of electrodes forming the electron gun is joined to the inner wall of the neck.

(Function) With the above configuration, the connection between the cathode end of the glass rod and the inner wall of the neck prevents the stem pin from bending due to external impact, and eliminates beam spot deformation due to tilting of the electron gun. be able to.

(Example) Hereinafter, the present invention will be described based on an example with reference to the drawings.

FIG. 3 shows a color picture tube which is an embodiment of the present invention. This color picture tube consists of a panel (10) and a panel (10).
The panel (1o) has an envelope consisting of a funnel (11) integrally joined to the panel (1o), and a phosphor screen (12) consisting of a three-color phosphor layer that emits blue, green, and red light on the inner surface of the panel (1o). A shadow mask (13) having a large number of electron beam passing holes formed therein faces the phosphor screen (12).
is located. Furthermore, an electron gun (14) that emits three electron beams is disposed within the neck (3) of the funnel (11). Then, the electron beam emitted from the electron gun (14) is deflected by a magnetic field formed by a deflection device (15) attached to the outside of the funnel (11) to horizontally and vertically scan the phosphor screen (12). It is formed into a structure that displays an image.

As shown in FIG. 1, the electron gun (14) has a cathode (k
), a grid (Gl) controlling electron emission from this cathode (k), (G2) and this grid (Gl)
, a pair of glass rod-shaped supports having a plurality of electrodes such as grids (G3) to (G6) that focus and accelerate the electron beam emitted through (G2), and these electrodes are located along the sides thereof. They are fixed together by a body (17), and a convergence cup (C) is attached to a grid (G6) on the electron beam emission end side.

Then, on the outer periphery of the convergence cup (C),
A plurality of valve spacers (18) are attached to press against an inner conductive film (4) applied to the inner surface of the cone portion of the envelope and extending onto the adjacent inner surface of the neck (3). This valve spacer (18) forms a conductor that guides the high voltage supplied from the anode terminal to the grid (G6) via the inner conductive film (4), and also holds the tip side of the electron gun (1). In order to improve the coaxiality between the electron gun (1) and the neck (3), a convergence cup (
C) are welded at positions that equally divide the outer periphery. on the other hand,
The cathode (K) side airtightly penetrates the stem (7) that seals the support part (6) and neck (3) end, which are integrally fixed to the glass rod-shaped support (I7) together with multiple electrodes. It is held by welding to the stem pin (8), and as shown in FIG. It is held by welding.

In such a holding structure for the electron gun (1), when assembling the electron gun (1), a convex portion (19) is formed, and the convex portion (19) connects the stem (7) and the neck (3). Using a glass rod (17) whose length is adjusted so that it is above the welding part, the convex part is simultaneously welded to the stem (7) and neck (3) when sealing the electron gun (1). (18) and neck (3
) can be obtained by welding.

By the way, when the electron gun (1) is held as described above, by appropriately setting the spring constant of the valve spacer (18), the tip side of the electron gun (1) is held stably against external shocks, etc., and at the same time the cathode The (K) side shows the convex portion (19) and neck (3) provided on the glass rod-shaped support (I7).
This and the welding of the support portion (6) and the stem pin (6) combine to provide an extremely strong holding force. Therefore, even if an external impact is applied, the stem pin is prevented from bending and the electron gun is prevented from tilting, which is the case with the conventional holding structure using only the support portion and the stem pin. In addition, by strengthening the holding on the negative 8iI (K) side as described above, it is possible to stably hold the valve spacer (18) on the tip side against external shock even if the spring constant of the valve spacer (18) on the tip side is weaker than that of conventional electron guns. Due to its weak spring constant, peeling of the inner conductive film (4) due to insertion into the neck (3) of the electron gun (1) and subsequent contact can be reduced, and the peeling of the inner conductive film (4) can be reduced. It is possible to prevent deterioration of withstand voltage characteristics due to

In the above embodiment, a convex portion was provided at one end of the glass rod-shaped support, but as shown in FIG. 4(a), a stem (7) was provided at one end of the glass rod-shaped support (17). and neck (
A holding structure having the same function and effect can also be obtained by providing a bent portion (2o) that reaches the welded portion with 3).

In addition, in order to ensure sufficient bonding between the neck and the glass rod-shaped support, as shown in (b), the glass rod-shaped support (
If a bead glass (21) having a softening point and thermal expansion coefficient similar to that of the neck (3) is bonded in advance to one end of the neck (2) and the glass rod-shaped support (17), the neck (2) and the glass rod-shaped support (17
), and the electron gun can be held more stably against external impact.

[Effect of the invention] When the cathode side end of the glass rod-shaped support that integrally supports the plurality of electrodes constituting the electron gun is bonded to the inner wall of the neck, the cathode side of the electron gun is firmly held, and the external The electron gun is held stably against shocks and the stem pin is prevented from bending. As a result, deformation of the beam spot due to tilting of the electron gun can be eliminated, and the characteristics of the cathode ray tube can be improved. In addition, by strengthening the holding force on the cathode side, the spring constant of the valve spacer that holds the tip side of the electron gun can be weakened, and peeling due to contact between the valve spacer and the inner conductive film can be reduced, and the inner conductive film Deterioration of withstand voltage characteristics due to peeling can be reduced.

[Brief explanation of drawings]

Figures 1 to 4 are detailed explanatory diagrams of this invention.
The figure shows a holding structure for an electron gun in a color picture tube, which is an example of the color picture tube, FIG. 2 shows a joint structure between the neck and a glass rod-shaped support supporting the electron gun, and FIG. Figures 4(a) and 4(b) are diagrams showing the structure of a color picture tube; Figures 4(a) and 4(b) are diagrams showing joint structures between different necks and glass rod-shaped supports; Figure 5 is a diagram showing the holding structure of a conventional electron gun. It is a diagram. 2... Neck 4... Inner conductive film 6...
Support part 7... Stem 8... Stem pin
14... Electron gun 17... Glass rod-shaped support 18... Valve spacer 19... Convex portion 20...
Bending portion 21...bead glass K...cathode

Claims (1)

[Claims] A cathode, a plurality of electrodes consisting of a grid that controls electron emission from the cathode, and a grid that focuses and accelerates an electron beam emitted through the controlling grid, and the plurality of electrodes. In a cathode ray tube in which an electron gun is disposed in the neck and includes a glass rod-shaped support that integrally supports the plurality of electrodes along the side surface of the tube, the cathode side end of the glass rod-shaped support is A cathode ray tube characterized by being joined to the inner wall of the neck.