JPH01194572A - Horizontal deflection amplitude adjusting circuit - Google Patents

Abstract

PURPOSE:To enable the large picture amplitude adjustment area of an image receiving tube to be obtained by controlling the change of the secondary pulse of a horizontal output transformer as the result of horizontal amplitude adjustment. CONSTITUTION:The second transformer 10 is added to a circuit. Pulse voltage Vpa generating at the both ends of a horizontal amplitude adjustment coil 5 is added to the primary coil 10a of the transformer 10 and the secondary coil 10b of it is inserted between a DC power source Eb and the primary coil 7a of the horizontal output transformer 7. Then, at that time, the polarity of the transformer 10 is fixed so that the pulse of which polarity is inverse to that of a collector pulse Vp at the connection point with the coil 7a. Therefore, the change of the peak value of the pulse generated to the coil 7b of the transformer 7 as the result of the horizontal amplitude adjustment can be controlled. Thus, the large picture amplitude adjustment area of the image receiving tube can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a horizontal deflection output circuit for a picture tube, and particularly to a horizontal deflection amplitude adjustment circuit thereof.

(Prior Art) Conventionally, the horizontal deflection output circuit of a receiving tube has mainly had a circuit configuration as shown in FIG. Here, 1 is a horizontal deflection output NPN transistor, which performs a switching operation in cooperation with a damper diode 2 by an excitation pulse P from a previous stage (not shown). Also, 3 is a retrace resonant capacitor, 4 is a horizontal deflection coil, 5 is a horizontal amplitude adjustment coil,
6 is a figure 8 correction capacitor. 7 is a horizontal output transformer, and 7a is its primary winding, to one end of which the DC power supply (voltage) Eb of the circuit is applied. Furthermore, 7b is a secondary winding of the horizontal output transformer 7, 8 connected thereto is a rectifier diode, and 9 is a smoothing capacitor.

In this way, according to the well-known principle, the horizontal deflection coil 4 receives horizontal deflection sawtooth wave currents 1y, 5. .

The horizontal deflection coil 4 is attached to the neck of the picture tube (not shown), so that the electron beam of the picture tube is deflected left and right.

At the same time, a collector pulse ■p is generated at the collector of the horizontal deflection output transistor 1 repeatedly in the horizontal deflection period, and this is transformed by the horizontal horn transformer 7 and is transformed into a secondary pulse Vp.
2, which is further rectified and smoothed by a rectifier diode 8 and a smoothing capacitor 9 to obtain a DC voltage E2.

This DC voltage [2 is supplied as a voltage for the circuit section of the receiver, but in particular, the peak value of the secondary pulse Vp2 is increased and the DC voltage E2 is used as the anode voltage of the picture tube. There are many things. In this case, the smoothing capacitor 9 can be omitted by utilizing the conductive grooves formed on the wall of the picture tube.

Also, if we take the inductance of the horizontal deflection coil 4 and the horizontal amplitude adjustment coil 5 as 'La', then the p-p (peak-to-peak) value of the horizontal deflection sawtooth wave lightning current 1y flowing here becomes (L+La> be inversely proportional.

Therefore, if the value of the inductance La is changed by adjusting the horizontal amplitude adjustment coil 5, the horizontal deflection sawtooth wave 7
The pp value of ji 'flt V also changes, and thereby the horizontal width of the image display portion (raster) on the picture tube surface can be adjusted.

(Problem to be Solved by the Invention) In this FIG. 6, the wave height (UV
If you try to find po, it will look like the following formula.

Vpo= (Eb −Ts)/(2+ a
)...(1) However, here, Ts is the scanning time of horizontal deflection, and C is the capacitance value of the retrace resonant capacitor 3.

As can be seen from equation (1), if, for example, the value of the inductance la is increased in an attempt to change the horizontal amplitude, the peak value ■pO of the collector pulse Vp becomes smaller.

As a result, the secondary pulse Vp2 generated in the secondary winding 7b of the horizontal output transformer 7 also decreases, and the DC voltage E2 obtained by rectifying this also decreases. This DC I''EE2 is also supplied to other parts within the same receiver, so if it decreases it will affect the performance.

In particular, as mentioned above, when the DC voltage E2 is set high and used as a high voltage for the anode of the picture tube, a decrease in the voltage value not only causes deterioration of focus quality but also increases deflection efficiency. However, the effect of the horizontal amplitude adjustment coil 5, which reduces the horizontal deflection sawtooth wave current Iy and narrows the horizontal amplitude, is weakened.

Further, as shown in FIG. 6, the pulse Vp3 obtained from the secondary winding 7b of the horizontal output transformer 7 may be supplied as is to circuits in other parts of the receiver.

For example, although not shown, there is a horizontal AFC circuit for matching the timing of an external reference synchronization signal and the waveform of the horizontal deflection output circuit, and it is often recommended to supply pulse Vp3 to this circuit as a comparison signal. It will be done.

In such a case, if the pulse p3 changes due to horizontal amplitude adjustment, the same +91 Shingetsu and the horizontal deflection output circuit waveform (for example,
Since the phase relationship with the horizontal deflection sawtooth wave lightning flow IV) is shifted, when the raster size is changed, the image is shifted in the horizontal direction.

Therefore, in order to avoid such inconvenience, the variable range of the horizontal amplitude adjustment coil 5 cannot be set to a large value. was the limit.

However, in recent years, there have been an increasing number of cases in which devices using such picture tubes are used as computer display devices. It is desirable to have as wide an image amplitude adjustment range as possible.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems, and includes a switching element that opens and closes at a horizontal deflection period, and a resonator connected in parallel with the switching element. A series circuit of a capacitor, a horizontal deflection coil, a variable inductance, and a figure-eight correction capacitor also connected in parallel with the switching element, and a DC power supply and a horizontal output transformer also connected in parallel with the switching element. In the horizontal deflection measurement circuit of a picture tube consisting of a series circuit with a winding, a pulse voltage obtained by transforming a transformer such as a transformer that transforms the pulse voltage generated at both ends of the variable inductance. is the horizontal output transformer with polarity such that the voltage per winding is added in series to the primary winding of the horizontal output 1-lance]-The horizontal output transformer is inserted in series with the primary winding of the lance. The above-mentioned conventional problems have been successfully solved by suppressing changes in the peak value of the pulses occurring in the secondary winding.

(Embodiment) FIG. 1 shows the most basic embodiment of the horizontal deflection amplitude adjustment circuit according to the present invention, in which the parts numbered 1 to 9 are the same as those in FIG. 6 above. It has the same function as the number part, so its explanation will be omitted.

In FIG. 1 of the present invention, a second transformer 10 is newly added to the conventional example shown in FIG. 6. This second transformer 10 has a horizontal amplitude adjustment coil 5 in its primary winding 10a.
A voltage Vpa is applied to the pulses generated at both ends of the transformer, and its secondary winding 10b is inserted between the DC power supply Eb and the primary winding 7a of the horizontal output transformer 7. At this time, the polarity of the second l-lance 10 is determined so that a pulse of opposite polarity to the collector pulse Vp is generated at the connection point with the primary winding 7a.

Here, when the peak value of the collector pulse Vp is Vpo, the peak value Vpa of the pulse voltage at both ends of the horizontal amplitude adjustment coil 5
This is the value divided by the inductance and [a.

Vpa=(l-a/(L-+-La))Vpo
...■ Therefore, if the value of the inductance la is increased, the peak value Vpa of the pulse voltage at both ends of the horizontal amplitude adjustment coil 5 will also increase.

This peak value (pulse voltage) Vpa is the second transformer 1
The primary winding 7 of the horizontally suspended cadence 7 is transformed by n times at 0.
added to one end of a. As mentioned earlier, this has the opposite polarity to the collector pulse Vp and is applied to the opposite end of the δ line, so in the end, the pulse voltage value Vp1 applied to the secondary winding 7a rest is given by the following formula: It becomes the sum of both absolute values, as in .

Vp1= vpO+ n Vpa
-(3) However, as mentioned earlier, the first term of this equation (3) decreases as the value of the inductance la of the horizontal scanning width adjustment coil 5 increases, but the second term decreases as the value of the inductance la increases. This is a direction of increase.

Therefore, if the coefficient n of the second term, that is, the winding ratio (transformation ratio) of the second 1 to lance 10, is appropriately determined, the waveform of the pulse voltage value Vp1 within the range of the change in the value of the inductance [a] It is possible to make the high price constant.

Assuming that the value of inductance La changes by 5% to 20% with respect to the value of inductance L of horizontal deflection coil 4, we actually perform several fifi r1 steps to find the value of n. becomes. The gauge cylinder type is omitted because it is very complicated.

Therefore, in FIG. 1, if the turns ratio of the second 1 to lance 10 is set to l: 0.57, the pulse voltage value applied across the primary winding 1i17a of the horizontal output transformer 7 will be
The peak value of p1 becomes constant, and as a result, the pulse voltage generated in the secondary winding 7b and the DC voltage E2 obtained by rectifying this
The value of is also made constant.

The value of this transformation ratio n=0.57 is based on the assumption that the value of the inductance L1 seen in the primary winding 7a of the horizontal output transformer 7 is 1 - larger than the value of the inductance L of the horizontal deflection coil 4. This is the calculation.

However, in reality, there are many cases where the value of this primary inductance L1 cannot be set sufficiently large due to various design constraints, especially when the horizontal output transformer 7 is used as a flyback lance to connect the DC voltage E2 to the picture tube anode. When using high pressure, -
In many cases, the inductance L1 of the next winding 7a cannot be set to a large value. Normally, the value of the inductance 1 of this secondary winding 7a is at least twice the value of the inductance of the horizontal deflection coil 4, or at least the same value at worst, in order to avoid increasing the reactive power handled by the circuit. to be designed.

If Ll = 51, finding the value of n in the same way will give n = 0.45, and if L1 = 21, n =
0.36, when Ll=L, n=0.26.

Here, the relationship between Ll/L and n is shown in FIG.

From this, the winding ratio (transformation ratio) n of the second transformer 10
If the circuit shown in FIG. 1 is configured by setting as described above, even if the value of the inductance 1-a of the horizontal amplitude adjustment coil 5 is adjusted, the output pulse (secondary pulse) of the horizontal output transformer 7
The peak value of Vp2 does not change, so the voltage supplied to each part inside the receiver, including the high voltage of the picture tube anode, is kept constant.

Further, FIG. 2 shows another embodiment of the present invention. That is, the object of the present invention is achieved here without adding another transformer as shown in FIG.

That is, in this FIG. 2, 11 is used as the horizontal amplitude adjustment coil.
Use one with two sets of windings like this.

For example, this has a structure as shown in Figure 3, so 1
A magnetic core 13 is inserted into and removed from a cylindrical coil bobbin 12 on which two independent windings 1a and 11b are wound.

When the core 13 is adjusted in this way, the value of the inductance a of the -order winding 11a changes, and as described above, the amplitude of the horizontal deflection sawtooth wave current IV changes, and the value between both ends (a-a') changes. A pulse voltage Vpa is generated.

Then, this pulse voltage Vpa is transformed and inverted by another secondary winding 11b wound on the same bobbin, and appears as a pulse voltage -nvpa. It is sufficient to have yJci on the primary side of '.

Horizontal output of this figure 2! - The circuit around the lance 7' is slightly different from that in FIG. Here, 14 is a boost diode, 15 is a boost capacitor, and if the secondary winding 11b is strong here, then 7a'.

7a'' and b' of the two divided primary windings, this is a series boost circuit commonly used in the past.

In such a circuit, windings 7a l, 7a l+
Let n1 and n2 be the number of turns of the boost capacitor 15. According to the well-known principle, the voltage across the boost capacitor 15 is EC=(
A DC voltage of n2/nl)Eb is generated. After working on it,
The actual DC power supply voltage of this horizontal deflection output circuit is Ebl
-Ec, so this circuit is useful when only a relatively low direct TiTi source (voltage) Eb can be prepared.

However, when trying to apply the present invention to such a series boost circuit, it is not necessary to insert a pulse voltage of -nVpa between the - led end of the transformer and the DC power supply [b, as shown in Figure 1. , 7 a + as shown in Figure 2,
7 a It will be added between the two primary windings of I+, between b and b'.

Even in this case, if n is determined correctly, the pulse voltage value between both ends of the negative secondary winding 7 a l can be made constant regardless of the horizontal amplitude adjustment, and the secondary winding 7 b, AC
etc. 1! ′? Each voltage applied is also constant (can be increased).

Of course, this may be applied to such a series boost circuit using the second one-herance 10 as shown in FIG. Using the adjustment coil 11, set this to DC current Hi as shown in Figure 1.
It may be connected between Eb and the primary winding 7a, and any combination is possible, including FIG. 4 in the next section.

Furthermore, FIG. 4 shows another embodiment of the present invention in which the horizontal amplitude adjustment can be performed electronically rather than mechanically as in FIG.

That is, here, the E-E type or E-
With saturable reactor 1G using I-type core 17,
Horizontal deflection sawtooth current (which changes the value of y).

In this figure 5, the windings wrapped across both legs of the core
2168 is the controlled winding, the control 1'5 wound on the central leg.
The inductance value changes depending on the magnitude of the direct current 1dc flowing through the wire 16b.

That is, when the value of the DC current IdC increases, one of the core side legs becomes saturated depending on the direction of the horizontal deflection sawtooth wave current Iy, and the inductance value of the controlled winding 16a decreases.

Therefore, as shown in Fig. 4, if the controlled 11 winding 16a is inserted in series with the horizontal deflection coil 4, and the variable DC current #A18 is connected to the υ1111 winding 16b to change the DC current 1dc, the horizontal It becomes possible to adjust the deflection amplitude.

If the windings in FIGS. 4 and 5 are composed of only lea and 16b, this is a horizontal amplitude adjustment circuit using a well-known saturable reactor.

In order to apply this to the present invention, as shown in FIG.
It is necessary to wind it in the same direction as 6a.

In FIG. 4, for example, if the inductance value between a and a' of the controlled wJ winding 16a is increased by reducing the amount of direct current 1 dc, the p-p value of the horizontal deflection sawtooth wave current 1y decreases, and at the same time a -a' pulse voltage Vpa
will also increase.

Therefore, the pulse voltage -nVl is applied to the tertiary winding IGc.
la is generated, which can be guided to the primary winding of the horizontal output transformer 7 in the manner described above. And this subject t2
Turning ratio (transformation ratio) between I1 winding 16a and tertiary winding 16c
As mentioned above, if n is determined according to the inductance ratio between the primary winding 7a of the horizontal output transformer 7 and the horizontal deflection coil 4, the voltage obtained from the horizontal output 1 - the secondary side of the lance 7 can be changed to the horizontal deflection. The amplitude can be kept constant regardless of how the amplitude is adjusted.

(Effects of the Invention) As is clear from the above detailed description, the horizontal deflection amplitude adjustment circuit of the present invention provides the following various effects. In other words, in the horizontal deflection output circuit of the picture tube, the horizontal deflection amplitude can be changed without changing the peak value of the pulse voltage generated on the secondary side of the horizontal output lance, effectively changing the horizontal width of the image. This is especially true when you want to widen the horizontal deflection amplitude variable range with a receiver that uses a circuit that combines a horizontal deflection output circuit and a high voltage output circuit. It is suitable for application to desired computer display-like devices.

It also utilizes a pulsed voltage on a secondary winding directly wound on a variable inductance for horizontal amplitude adjustment that is manually adjusted.
By doing so, it is possible to suppress fluctuations in the secondary pulse of the horizontal output transformer due to horizontal amplitude adjustment with a very small price increase.

In addition, if the variable inductance is a saturable reactor, the horizontal amplitude can be electronically adjusted by using the pulse voltage of the winding wound in parallel with the controlled winding. The secondary pulse of the output transformer does not fluctuate.

Furthermore, the appropriate value of the winding ratio of the transformer for obtaining the above-mentioned pulse voltage becomes clear, thereby facilitating the design for achieving the above-mentioned effect.

[Brief explanation of the drawing]

1 and 2 are diagrams showing respective embodiments of the horizontal deflection amplitude adjustment circuit according to the present invention, FIG. 3 is a structural diagram of parts used in FIG. 2, and FIG. 4 is a further embodiment of the present invention. Figure 5 is a structural diagram of the parts used in Figure 4, Figure 6 shows an example of a conventional circuit, Figure 1 and Figure 7 are diagrams showing the relationship between 1/L and n. be. 1...Horizontal deflection output NPN transistor, 2...
Damper diode, 3...Return resonant capacitor, 4...Horizontal deflection coil, 5.11...Horizontal amplitude adjustment coil, 6...Figure 8 correction capacitor, 7.7'...Horizontal quadrence , 7a, 7a', 7a'', 10a, 11a...
-Next winding, 7b, 7c, 10b, 11b・
... Secondary winding, 8 ... Rectifier diode, 9 ... Smoothing capacitor, 10 ... Second transformer (transforming means),
12... Coil bobbin, 13... Core, 14...
Boost diode, 15... Boost capacitor, 16... Saturable reactor, 16a... Controlled winding, 16b... Control winding, 16C... Tertiary winding, 17... E-E type or E-I type core, 18...
Variable DC current source, C...Capacitance value of return line resonant capacitor 3, Eb...DC power supply (voltage), EC...Boost voltage, E2...
DC voltage, ldc...DC current, Ty...horizontal deflection sawtooth wave current, shi...inductance of horizontal deflection coil 4, la...
- Inductance of the horizontal amplitude adjustment coil 5 and the winding 11a, n... Turning ratio (transformation ratio), P... Excitation pulse, TS... Scanning time of horizontal deflection,
Vp...Collector pulse, Vpa...Pulse voltage (peak value), Vpl...Pulse voltage value, Vp2...Secondary pulse,
Vp3...Pulse. Figure 1 Vp Figure 2 Figure 3 Figure 4

Claims (4)

[Claims] (1) Series of a switching element that opens and closes at the horizontal deflection period, a resonant capacitor connected in parallel with the switching element, a horizontal deflection coil, a variable inductance, and an S-shaped correction capacitor also connected in parallel with the switching element. In the horizontal deflection output circuit of the picture tube, which comprises a series circuit of a DC power supply and a primary winding of a horizontal output transformer, which are also connected in parallel to the switching element, a pulse is generated across the variable inductance. A pulse voltage obtained by transforming a voltage transformer by the transformer is connected to the primary winding of the horizontal output transformer with polarity such that the voltage per winding is added to the primary winding of the horizontal output transformer. A horizontal deflection amplitude adjustment circuit characterized by being inserted in series with the winding. (2) The transformation means is provided by a secondary winding wound directly on the variable inductance, and the transformed pulse voltage obtained here is added to the primary winding of the horizontal output transformer. 2. The horizontal deflection amplitude adjusting circuit according to claim 1, wherein the horizontal deflection amplitude adjusting circuit is inserted in series with the primary winding. (3) The variable inductance is a controlled winding of a saturable reactor whose inductance value changes depending on the value of DC current flowing through the control winding, and the controlled winding is connected to a winding wound in parallel with the controlled winding. 2. The horizontal deflection amplitude adjusting circuit according to claim 1, wherein the horizontal deflection amplitude adjusting circuit is inserted in series with the primary winding of the horizontal output transformer so that the generated pulse voltage is added to the primary winding of the horizontal output transformer. (4) Horizontal deflection according to claim 1, characterized in that the transformation ratio when transforming the pulse voltage generated at both ends of the variable inductance is approximately 0.26 or more and 0.57 or less. Amplitude adjustment circuit.