JPS6318298B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resistor built-in cathode ray tube, which is used, for example, in a color television picture tube, and includes a voltage dividing resistor that is incorporated together with an electron gun in the tube.

For example, in a cathode ray tube such as a color television picture tube, in addition to an anode voltage, there is a device that applies a high-voltage convergence voltage to a convergence electrode, for example. In this case, supplying multiple types of high voltage from the outside to the cathode ray tube causes many problems in terms of withstand voltage, etc., so a voltage dividing resistor is built into the tube along with the electron gun, and the anode voltage is divided by this. There is a cathode ray tube with a built-in resistor that obtains a required convergence voltage and supplies it to a convergence electrode.

An example of such a cathode ray tube, such as a color television picture tube, is shown in FIG. 1. An electron gun 2 is disposed within a neck portion 1a of a tube body 1. electron gun 2
For example, for three cathodes K corresponding to red, green and blue, the first grid G ₁ , the second grid G ₂ , the third grid G ₃ , the fourth grid G ₄ and the fifth grid G _{5 are} commonly used. are arranged in sequence, and the convergence means 3 is arranged after the fifth grid _G5 . Each of the electrodes G ₁ to _{G 5} and the convergence means 3 are mechanically connected by a beading glass 4 while maintaining a required positional relationship with each other. The convergence means 3 has inner deflection electrode plates 3a and 3b facing each other, and these electrode plates 3a on the outside thereof.
and an outer deflection electrode plate 3 disposed opposite to 3b.
c and 3d.

In such a configuration, e.g.
A high anode voltage is applied to G ₃ and the fifth grid G ₅ , and a similar anode voltage HV is applied to the inner deflection electrode plates 3a and 3b of the convergence means 3.
Therefore, the third grid G ₃ and the fifth grid G ₅
are electrically connected to each other by a conductive wire 5,
A conductive plate 6 is provided at the rear edge of the fifth grid _G5 , to which the inner deflection electrode plates 3a and 3b of the convergence means 3 are electrically connected. Inside the funnel part 1b of the tube body 1, an internal conductive film 7 is deposited so as to partially extend over the neck part 1a. A high anode voltage Vo is applied to the membrane 7. On the other hand, a conductive spring 8 is attached to the conductive plate 6, which contacts the internal conductive film 7 and causes the inner deflection electrode plates 3a, 3b of the convergence means 3 to
The anode voltage Vo is applied to the fifth grid _G5 and the third grid _G3 , respectively. Each cathode K, a heater (not shown) disposed within the cathode, and a first grid G ₁ ,
The second grid G2 _and the like are connected to terminal pins 10 corresponding to the husband and wife, which are embedded in a stem 9 sealed to the base of the neck portion 1a of the tubular body 1, and power is supplied through these terminal pins.

A considerably high convergence voltage is applied to the outer deflection electrode plates 3c and 3d of the convergence means 3, respectively, although the voltage is lower than the anode voltage Vo.
The voltage supply to c and 3d is a voltage obtained by dividing the anode voltage Vo by a voltage dividing resistor 11 built in and arranged along the electron gun 2 in the network part 1a of the cathode ray tube tube body 1.
Give as Vd.

This voltage dividing resistor 11 is made of an insulating substrate 1 made of ceramic such as alumina, for example, as shown in FIG.
2, terminal portions 13a, 13b and 13c each having, for example, a conductive layer applied thereto, are applied, and between each terminal portion 13a and 13b and between 13b and 13c,
The voltage dividing resistors 14 (resistors 14A and 14B) are respectively deposited in a zigzag pattern so as to have required resistance values R ₁ and R ₂ having a predetermined ratio. And the terminal part 13 at one end
a is electrically and mechanically connected to the fifth grid G ₅ by means of a conductive attachment piece 15, and the other terminal 13c is connected to one pin 10 of the stem pins 10.
A is electrically connected to the resistor 11 by a conductive mounting piece 16, and both mounting pieces 15 and 16 connect to the resistor 11.
is held mechanically. Then, the intermediate terminal 13b of the resistor 13 is electrically connected to the outer deflection electrode plates 3c and 3d of the convergence means 3. 17
is an insulating coating material that covers the resistor 14.

According to such a configuration, if voltage Vo is applied across the resistor 14, that is, to the series circuit consisting of resistors _R1 and _R2 as shown in FIG.
The voltage Vd obtained at the midpoint of connection between R ₁ and R ₂ , that is, the intermediate terminal 3b, is as follows: Vd = Vo・R ₂ /R ₁ + R ₂ ...(1) Therefore, this Vd is the required convergence voltage. If resistors R ₁ and R ₂ are set so that
inner deflection electrode plate 3a of convergence means 3;
A required potential difference can be given between the inner and outer deflection electrode plates 3c and 3d, and each electron beam passing between the inner and outer deflection electrode plates 3a and 3c and between 3b and 3d is electrostatically deflected. Deflection electrode plate 3
Although not shown, the central electron beam passing between a and 3c can be converged on a fluorescent surface.

However, in reality, when the voltage Vo fluctuates,
That is, when this has an alternating current component, the relationship in equation (1) above does not hold, and the voltage Vd does not follow the voltage Vo, causing fluctuations in the voltage between the inner and outer deflection electrode plates of means 3. . The reason why the relationship in equation (1) no longer holds true is that in an actual electron gun,
Stray capacitance occurs between each electrode, support pin, stem pin, etc., as shown by the broken line in Figure 3.
Capacitance based on this stray capacitance in parallel with each resistor R ₁ and R ₂
This is due to the existence of C ₁ and C ₂ . That is, if such capacitances C ₁ and C ₂ exist, the following equation (2)
is converted to

L (Vd) = 1/R ₁ +jωC ₁ /1/R ₁ +jωC ₁ +1/R ₂ +j
ωC ₂・L(Vo) ……(2) (L indicates Laplace transform) The transfer number of Vo→Vd is G(jω)=1/R ₁ +jωC ₁ /1/R ₁ +1/R ₂ +jω (C
₁ + C ₂ )...(3) Therefore, if we find the necessary and sufficient condition that the phase error and gain of Vo and Vd do not depend on the angular velocity ω, R ₁・C ₁ = R ₂・C ₂ ...(4) It is. In other words, if the relationship in equation (4) is selected, even if the supply voltage Vo fluctuates, the relationship in equation (1) will be maintained and Vd
will follow. However, in reality, the voltage
Resistances R ₁ and R ₂ are used to ensure that Vd obtains the required convergence voltage. Since R ₂ has a considerably larger value than R ₁ , the capacitance is required to satisfy equation (4). C ₁ needs to be chosen to be a much larger value than the capacitance C ₂ , but the capacitance due to the actual stray capacitance
C ₁ and C ₂ are on the order of several pF, and the difference between their values is small, so Vd does not follow fluctuations in Vo.

The present invention provides a built-in resistor cathode ray tube that includes such a built-in resistor for voltage division, in which a capacitive element for time constant correction is actively installed in parallel with the resistor R ₁ so as to satisfy the above-mentioned equation (4). By connecting, we obtain the ratio of capacitors C ₂ and C ₁ corresponding to the ratio of resistors R ₁ and R ₂ , and divide the voltage
This is to enable Vd to follow fluctuations in the voltage Vo supplied to the voltage dividing resistor. In particular, in the present invention, a capacitive element for time constant correction is provided inside the tube of the cathode ray tube, and Simplification of structure used to be aimed at simplifying assembly and manufacturing.

An example of a cathode ray tube with a built-in resistor according to the present invention will be explained with reference to FIG.
Portions corresponding to those in the figures are designated by the same reference numerals and redundant explanation will be omitted.

In the present invention, as shown in FIG. 5, a high dielectric substrate 20, such as ceramic, is prepared, which is placed inside the cathode ray tube and hardly generates gas that would lower the vacuum inside the tube. A time constant correction capacitive element 22 is constructed in which a counter electrode 21 is formed by depositing a conductive layer such as an electroless plating layer of Ni on the opposing surfaces. And this capacitive element 22
is attached to the electrode inside the tube body 1. This element 22
is connected in parallel with the resistance _R1 caused by the resistor 14A of the voltage dividing resistor 11 explained in FIG. For this reason, as shown for example in _FIG . A metal spring 23 is attached, and the capacitive element 22 is elastically inserted between the free end of the metal spring 23 and one of the outer deflection electrode plates, for example, the electrode plate 3d, and further attached by welding or the like as necessary. In this case, element 2
Each electrode 21 of 2 is connected to the electrode plate 3d and the spring 2, respectively.
Attach it so that it is electrically connected to 3. That is, in the present invention, the resistance R ₁ due to the resistor 14A of the voltage dividing resistor 11 explained in FIG.
The capacitor C ₁ inserted in parallel with the capacitor C 1 is determined mainly by the capacitance of the capacitive element 22, including stray capacitance such as inter-electrode capacitance. The capacitance value of this element 22 is determined by the ratio of the capacitance C ₁ due to this to the capacitance C ₂ due to the stray capacitance inserted in parallel to the resistance R ₂ due to _the resistor 14B _.
, so that the above equation (4) holds true.

In the illustrated example, the capacitive element 22 is disposed between one of the outer deflection electrode plates of the convergence means 3 and the spring. It is connected to at least one of the inner deflection electrode plates 3a and 3b and at least one of the outer deflection electrode plates 3c and 3d of the convergence means 3, so that it is located at a position where it does not interfere with the passage of the electron beam between these electrode plates. , or between extensions of the electrode plates themselves.

According to the configuration of the present invention described above, since the capacitive element 22 for time constant correction is actively provided so that the above formula (4) holds true, the voltage applied to the voltage dividing resistor is
When Vo fluctuates, a divided voltage Vd is obtained following the fluctuation, so that the required voltage is always supplied between the inner and outer deflection electrode plates of the convergence means 3.

According to the configuration of the present invention described above, the capacitive element 22 is disposed within the tube body 1, and furthermore, this element 2
By directly attaching the element 22 to the electrode, there is no need to lead out the terminal to the outside, the number of parts for fixing the element 22 is reduced, and manufacturing and assembly is simplified.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main part of a conventional cathode ray tube with built-in resistor, Fig. 2 is a top view of its voltage dividing resistor, Fig. 3 is an explanatory diagram thereof, and Fig. 4 is a cathode ray tube with built-in resistor according to the present invention. FIG. 5 is a cross-sectional view of the main part of the tube, and FIG. 5 is a cross-sectional view of the capacitive element. 1 is a tube body, 2 is an electron gun, 11 is a voltage dividing resistor, 2
2 is a capacitive element.

Claims (1)

[Claims] 1 A high voltage dividing resistor is built in the tube, and a capacitive element for time constant correction is built in to obtain a divided voltage that follows fluctuations in the high voltage supplied to the resistor. The element is a cathode ray tube with a built-in resistor, in which a high dielectric material is sandwiched between the opposing electrodes, and opposing electrodes are attached to the opposite surfaces thereof, and the element is connected to a desired electrode in the tube.