JPS6035163Y2 - electron gun structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an integrated electron gun assembly in which three electron guns are arranged in a row and are housed in a color picture tube.

The three-pole portion of an integrated electron gun assembly in which three electron guns are arranged in a row has a structure as shown in FIGS. 1 and 2, for example.

That is, the cathode 2 has a heater 1 therein, and a first grid 1, a second grid, and a third grid 5 are arranged opposite to each other on the electron emitting surface of the cathode 2 and have electron beam passage holes. Electrons emitted from the electron emitting surface of the cathode 2 by ignition become electron beams R, G, and B, which are controlled by the first grid 11 and second grid, accelerated by the third grid 5, that is, the accelerating electrode, and are further not shown. The light is focused by a main lens formed between the fourth grid and the third grid 5, and focused on the fluorescent surface through the aperture of the shadow mask.

In this case, in the primary color drive system, a color signal voltage is applied to each cathode, and the electron beam R is , G, and B can be set to desired values.

In the figure, 8 is an insulated support rod that supports each of the electrodes.

In this case, the cutoff voltage E0 at the three poles, that is, the cathode 2, the first grid 1, and the second grid (1) is expressed by the following equation, and when the value of the right term becomes dog, the electron beam current increases.

Eo～-Lotus911- (Gl/K) (Gl/G2 Distance C1t between the first grid and the second grid: Thickness of the first grid ECI ``Voltage applied to the first grid Among these, φG1v Gxtt Since ECI is constant in the same electron gun structure, E is ``1/K and 01/G2.
That is, it depends on the distance between the first grid 3 and the cathode 2 and the distance between the first grid 1 and the second grid, and as shown in the above equation, the cutoff voltage is inversely proportional to G1/KxG1/G2, and generally Gl / is about 1n of Gt/G2, and G1/
If the same change occurs in K and G1/G2, the effect on G1/ will be greater.

However, the shapes of the first grid 1 and the second grid are each formed into an integrated shallow dish shape as shown in FIGS. The portions 33 and 43 are formed with a step between the flat electrode bodies 31 and 41 in which electron beam passage holes are formed and the side wall portions 3□ and 42.

When an electron gun assembly having such a triode is installed in a color picture tube and the heater 1 is ignited to heat the cathode 2 and emit thermoelectrons from the electron emission surface, the radiant heat from the cathode 2 first causes As the flat electrode body 31 of the first grid 1 shown by the broken line is heated as shown in FIG.
The grid is transformed into a first grid h shown by a solid line.

Next, after a while after ignition, the first grid 1 remains curved as shown in Figure 4;
Due to the radiant heat from a, the second grid 4 shown by the broken line is bent in the direction of the arrow 10 and deformed into the second grid 4a shown by the solid line.

That is, considering Gl/ and Gt/G2 mentioned above, near the central electron beam passage hole, G1/ becomes large, and G□
/G2 becomes small, and in the vicinity of the electron beam passage holes on both sides, G and / become small, and G□/G2 becomes large.

The first grids 1 and 1 and the second grid in FIG.
When we measured the temperature rise and elongation of the grids E and C, we found that the temperature rise was indicated by the dotted line 11 for the first grid 3 and the dotted line 12 for the second grid 4, and the elongation was The values shown by the solid line 31 for the first grid main and the solid line 32 for the second grid 4 were obtained, respectively.

That is, T in the figure.

is at the time of ignition, T1 is when the temperature of the first grid 3 starts to rise, T
2 is when the temperature of the second grid 4 starts to rise, T3. T4 is T5 when the temperature rise of each electrode starts to slow down.
．． T6 indicates the time when the temperature of each electrode becomes stable.

As can be seen from FIG. 5, there is a considerable difference in temperature rise between the first grid 3 and the second grid 4.

Next, after stabilizing the temperature of a color picture tube with the first grid 1 and the second grid having different temperature rises, the electron beam currents of the three electron guns are combined, cooled, and then re-ignited. Figure 6 shows the changes in .

In the figure, a curve 13 shows the electron beam current at the center, and a curve 14 shows the changes in the electron beam current on both sides.

That is, the time shown in FIG. 6 corresponds to the time shown in FIG. 5.

After ignition, from the time when the temperature of the first grid 3 at T1 starts to rise, that is, when it starts to curve in 9 directions as shown in Figure 4a, to the time when the temperature of the second grid 4 starts to rise, that is, at T2, that is, when it has already curved in 10 directions as shown in Figure 4. As can be seen from the explanation of the above-mentioned equation, until the time when the electron beam current 13 at the center starts to decrease, the electron beam current 13 at the center is small and the electron beam currents 14 at both sides are large, and the difference between them widens.

Next, the difference between the center electron beam current and the electron beam currents on both sides does not change significantly from T2 when the temperature of the second grid 3 starts to rise until T3 when the temperature rise of the first grid 3 starts to slow down.

Next, from T3 to T, when the temperature rise of the second grid 4 begins to slow down, the difference in both electron beam currents gradually decreases, and from T4 until T6, when the temperature of the second grid 4 becomes stable, the electron beam After the current is reversed, it settles to the set electron beam current I.

Normally, the time from T1 to T6 is approximately 3 minutes to 159
If the central electron gun is used for green G, the electron guns on both sides will be red R blue B, but because the electron beam current from both sides is large, the white part will turn magenta and the screen will not be normal. You won't be able to see it.

The above-mentioned phenomenon is particularly likely to occur when the first grid and the second grid are integrated and an interlocking cathode is used.

The present invention was made in view of the various drawbacks of the conventional technology, and
By taking into account the first grid and the second grid or the components forming the second grid, and especially by causing the second grid to deform rapidly, the elapsed time until the screen colors return to a normal visible state. The purpose of the present invention is to provide an electron gun structure that can shorten the length of the electron gun.

Next, one embodiment of the electron gun assembly of the present invention will be described with reference to FIGS. 7 and 8.

In the figure, the same reference numerals as in the conventional one indicate the same parts.

That is, a cathode 2 having a heater 1 therein, and a first grid z1, a second grid 4, and a third grid 5 each having an electron beam passage hole provided oppositely to the electron emitting surface of the cathode 2.
The electrons emitted from the electron emitting surface of the cathode 2 by ignition of the heater 1 become electron beams R, G, and B, which are controlled by the first grid 23 and the second grid 5, and are controlled by the third grid 5. That is, it is accelerated by the accelerating electrode, further focused by the main lens formed between the fourth grid (not shown) and the third grid 5, and focused on the fluorescent surface through the aperture of the shadow mask. In this case, a signal voltage is applied to each cathode,
It is almost the same as the conventional electron gun structure in that the electron beam R, G, and B currents are set to desired values by the first grid 23 and the second grid 24, which are each integrally formed in the shape of a shallow dish. However, in this embodiment, the degree of curvature due to heating of the first grid i1 and the degree of curvature of the second grid i1 are determined by considering the thermal expansion coefficients of the first grid operator and the members forming the second grid 24. By changing the degree of curvature due to heating of 24 and changing G1/G2 to the desired values in the above-mentioned cutoff voltage formula, the elapsed time until the screen color returns to a normal visible state is shortened. It is set to do so.

Next, the relationship between the elongation of the grid due to temperature rise and time will be explained with reference to FIG.

In FIG. 9, a solid line 31 represents the elongation due to thermal expansion of the first grid main body 1, and the coefficient of thermal expansion of the members constituting the second grid (2) is greater than the coefficient of thermal expansion of the members constituting the first grid main body. Then, as shown by the solid line 33, the elongation of the second grid point increases at a steeper slope than T2' at the start of temperature rise.

The solid line 31 shows the elongation of the first grid 23.

Since such elongation has a correlation with the curvature of the electrode in a shallow dish electrode, the curvature of the second grid (2) is larger near the electron beam passage holes on both sides than the conventional curvature shown in Figure 4. Therefore, the cutoff voltage is E.

In the formula, it is possible to make 01/G2 larger than the conventional one.

T in Figure 9. ' is at the time of ignition, T□' is the first grid 2
3, T2' is the time when the temperature of the second grid H starts to rise as described above, T3', T,' is the time when the temperature rise of each electrode starts to become gradual, T,', T6
′ indicates the time when the temperature of each electrode becomes stable.

Next, as in the conventional electron gun structure, the first grid 21 and the second
The change in the electron beam current when a color picture tube equipped with a grid (1) is cooled after the temperature has stabilized, the electron beam currents of the three electron guns are combined, and then re-ignited will be explained with reference to FIG.

Curves 13 and 14 shown in FIG. 10 are curves showing changes in the electron beam current in FIG.

That is, the time shown in FIG. 10 corresponds to the time shown in FIG. 9.

From the start of the temperature rise of the first grid 23 at T□', which starts in a very short time after the ignition of ', to the start of temperature rise of the second grid T2', the electron beam current in the center indicated by the dashed-dotted line 16 is small, and the electron beam current is small at one point. The electron beam currents on both sides indicated by the chain line 17 increase, and the difference between them increases.

Next, when the temperature of the second grid (■) starts to rise, the first
T3' when the temperature rise of the grid 23 starts to slow down
Up to this point, the difference between the center electron beam current and the electron beam currents on both sides does not change significantly, but from T2' onwards, the degree of curvature of the second grid H increases rapidly as shown in Figure 9, so the electron beam currents on both sides become the same as before. The less the one, the more the magenta color will be paler.

Next, when the temperature of the second grid H becomes stable from T3', T6
Until ', the two electron beam currents cross once and finally settle to the set electron beam current I.

In this case, in the case of this embodiment, the intersection occurs earlier than in the conventional case, and there is no visual problem at T7'. This will take less time, and the screen will return to a state where the colors look normal sooner.

In other words, the time it takes for the current difference between the central electron beam and the electron beams on both sides to become small enough to cause no problem due to visual acuity becomes shorter from T7 to T7', and therefore the time it takes for the current to return to a normal visual state becomes shorter. It has the effect of becoming darker.

In FIG. 10, a indicates the current difference between the conventional double-side electron beam and the center electron beam, in which the color appears normal, and the right side of the figure from this T7 is the range in which the color appears normal.

Further, b indicates the current difference between the two electron beams according to the present invention and the hot electron beam, and the color appears normal, and is approximately the same amount as a.

From this, it can be seen that with the device of the present invention, the area on the right side of the figure from T7' can be seen normally, and the stabilization time is faster than with the conventional device, and the elapsed time until the screen color returns to a normal visible state. can be shortened.

According to experiments, G1/K = 0.15mm, G1/
G2 = 0.40 In the case where the first grid l-1 and the second grid ■ have the same shape, the stable temperature difference between the first grid operator and the second grid 24 and G□/, G1/
If the optimum value is determined by the ratio of G2, it will be about twice as much.As for the parts that are close to this, the members of the first grid operator are iron (coefficient of expansion 12X10-6), and the members of the second grid operator are aluminum (coefficient of expansion 23X10-6). ) was optimal.

Also, Gt/=0.15mmt Gl/G2=0.3-
So the optimal value is about 1. In order to satisfy this requirement, the first grid 23 should be made of stainless steel (coefficient of expansion 16 x 1).
O-6) Aluminum (expansion coefficient 23 x 10-') was optimal for the second grid member.

The above-mentioned embodiment is a typical example of the present invention, and various modifications are possible, such as making the first grid and second grid flat electrode bodies different shapes, and making the side wall portions different in height. Of course.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a conventional electron gun assembly, Fig. 2 is a sectional view taken along line XX' in Fig. 1, Fig. 3a is a perspective view of the first grid, Figure 3 is a perspective view of the second grid, Figure 4a is an explanatory diagram showing a state in which only the first grid has thermally expanded, and Figure 4 shows a state in which both the first and second grids have thermally expanded. Figure 5 is a curve diagram showing the relationship between the temperature rise and elongation of the first and second grids and time, and Figure 6 is a curve diagram showing the relationship between changes in electron beam current at the center and both sides and time. 7 is a side sectional view of the first embodiment of the electron gun assembly of the present invention; FIG. 8 is a sectional view taken along line Y-Y' in FIG. 7; The figure is the first
FIG. 10 is a curve diagram showing the relationship between the temperature rise and elongation of the grid and the second grid versus time, and FIG. 10 is a curve diagram showing the relationship between the center and both sides of the electron beam current versus time for both the present embodiment and the prior art. 3, h, 2nd main... 1st grid, 4. Ha924
...Second grid, 3□, 4□...Side wall part, 33.43...Eplanted part.

Claims (2)

[Scope of utility model registration request] (1) Consisting of at least a first grid, a second grid, and a third grid, each integrally formed with three cathodes arranged in a row, each having an electron beam passing hole in the center and on both sides, and facing each other, The first grid and the second grid have a planted part having a step between the flat electrode body and the side wall part, and the planted part is insulated and supported so that the gap is larger than the interval between the flat electrode bodies. The second
An electron gun assembly characterized in that the coefficient of thermal expansion of the member forming the grid is greater than the coefficient of thermal expansion of the member forming the first grid. (2) The first grid and the second grid have the same shape, and the ratio of the thermal expansion coefficients of the members forming each grid is set to 1.
: 1.47"7 to 1:2.0. The electron gun assembly according to claim 1 of the utility model registration claim.