JP2007028655A - Vertical deflection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the vertical deflection apparatus that can sufficiently correct an upper-lower pin-cushion distortion without being affected by a crosstalk from a horizontal deflection coil to a vertical deflection coil. <P>SOLUTION: A parabola modulation circuit 12 which performs amplitude modulation of a horizontal parabola signal HP by a vertical modulation signal VM by multiplying the horizontal parabola signal HP and the vertical modulation signal VM, modulates a phase of the horizontal parabola signal HP based on the vertical modulation signal VM, and outputs the modulated horizontal parabola signal HP1 to a correction current output amplifier 7. When an NS pin-cushion distortion on a screen of a CRT tube serves right-left asymmetric, a horizontal parabola signal generation circuit 32 is set so as to generate a right-left asymmetric horizontal parabola signal HP. A gull-wing distortion can be corrected by combining a sine-wave to a parabola waveform in the horizontal parabola signal generation circuit 32. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vertical deflection apparatus including a correction circuit that corrects upper and lower pincushion distortion of a CRT (cathode ray tube).

  In CRT, since the distance from the center point of deflection to the tube surface (phosphor surface) becomes longer in the peripheral part, the deflection of the electron beam is greatest at the four corners of the screen. As a result, upper and lower pincushion distortion and left and right pincushion distortion occur in the image displayed on the CRT screen. In particular, these pincushion strains are also called pincushion strains, upper and lower pincushion strains are called NS (north-south) pincushion strains (pincushion strains), and left and right pincushion strains are EW (east-west) pincushion strains (pins). This is called cushion distortion. Such pincushion distortion increases as the deflection angle of the electron beam increases.

  FIG. 16A shows an example of NS pincushion distortion on the CRT tube surface, and FIG. 16B is a waveform diagram showing NS pincushion distortion correction current superimposed on the vertical deflection current. In FIG. 16, H indicates a horizontal scanning period, and V indicates a vertical scanning period.

  As shown in FIG. 16 (a), NS pincushion distortion on the tube surface of the CRT has a constricted shape at the center compared to the left and right ends. NS pincushion distortion can be corrected by moving the center of the horizontal scanning line up and down as indicated by the arrows. Therefore, as shown in FIG. 16B, an NS pincushion distortion correction current (hereinafter abbreviated as a correction current) that changes in a parabolic manner in the horizontal scanning period to a sawtooth vertical deflection current VI that changes in the vertical scanning period. Overlap am. The correction current am has a positive polarity in the first half of the vertical scanning period (upper half of the screen), and has a negative polarity in the second half of the vertical scanning period (lower half of the screen). The amplitude of the correction current am increases from the center of the screen toward the upper and lower ends.

  Conventionally, a supersaturation reactor is used to superimpose a correction current on a vertical deflection current, or a transformer is inserted in series with a vertical deflection coil, and the transformer is a parabolic current with a horizontal scanning period (hereinafter referred to as a horizontal parabolic current). Transformer system driven by has been adopted.

  FIG. 17 is a schematic diagram showing NS pincushion distortion correction by a conventional supersaturated reactor system, (a) showing a supersaturated reactor, and (b) showing a relationship between magnetic flux density B and magnetic field H of the supersaturated reactor. .

In FIG. 17A, the supersaturated reactor core 50 has three legs. An iron core 51 is disposed on the iron core 50, and a permanent magnet 52 is disposed on the iron core 51. A horizontal deflection current HI is passed through the windings L _H1 and L _H2 of the legs on both sides of the iron core 50. Thereby, the magnetic flux Φ _H is generated. The flowed vertical deflection current VI in winding L _V leg of the central portion of the core 50. As a result, the magnetic flux Φ _V is generated. Further, a magnetic flux Φ _B is generated by the permanent magnet 52. As shown in FIG. 17B, in the supersaturated reactor, when the magnetic field H increases, the magnetic flux density B is saturated.

17A, the correction current am is superimposed on the vertical deflection current VI supplied to the vertical deflection coil, as shown in FIG. 16B. The same control is performed in the transformer system. In this way, NS pincushion distortion is corrected.
JP 59-274 Japanese Patent Laid-Open No. 62-31268 JP 58-73281 A

  Inside the deflection yoke, a horizontal deflection coil and a vertical deflection coil are arranged so as to be orthogonal to each other. Due to problems in manufacturing the deflection yoke, the orthogonality between the horizontal deflection coil and the vertical deflection coil is not always guaranteed. Therefore, a current component due to the horizontal deflection current is induced from the horizontal deflection coil in the deflection yoke to the vertical deflection coil by electromagnetic coupling.

  Further, the horizontal flyback pulse generated in the horizontal deflection coil during the horizontal blanking period reaches a voltage of several hundred Vp-p (volt peak-to-peak), and the harmonic component of the horizontal flyback pulse is horizontal. Since it has a frequency that is tens of times the scanning frequency, the horizontal deflection coil and the vertical deflection coil are coupled via a stray capacitance between the horizontal deflection coil and the vertical deflection coil. Thereby, a current component due to the horizontal deflection current is induced from the horizontal deflection coil to the vertical deflection coil by electrostatic coupling.

  Hereinafter, induction of a current component from the horizontal deflection coil to the vertical deflection coil is referred to as HV crosstalk, and current component induced from the horizontal deflection coil to the vertical deflection coil is referred to as HV crosstalk component. When the HV crosstalk component is superimposed on the vertical deflection current supplied to the vertical deflection coil, the scanning line is distorted and the displayed image is distorted.

  A current component due to the vertical deflection current is induced from the vertical deflection coil to the horizontal deflection coil. However, the horizontal deflection current is as large as ten and several Ap-p (ampere peak to peak), whereas the vertical deflection current is as small as 1 to 2 Ap-p. Further, the voltage of the pulse generated in the vertical deflection coil in the vertical blanking period is less than 100 V, and the frequency is from several tens of hertz to several hundreds of hertz. Therefore, the current component induced by electromagnetic coupling and electrostatic coupling from the vertical deflection coil to the horizontal deflection coil is so small that it hardly causes a problem.

  In the conventional supersaturation reactor type and transformer type NS pincushion distortion correction, correction in consideration of HV crosstalk generated in the deflection yoke is not performed. FIG. 18 is a diagram for explaining HV crosstalk.

  18A shows the vertical deflection current VI on which the correction current is superimposed, FIG. 18B shows the correction current am, FIG. 18C shows the HV crosstalk component CR, and FIG. 18D shows the correction current am. A composite waveform with the HV crosstalk component CR is shown. In FIG. 18A, the correction current superimposed on the vertical deflection current VI is schematically shown. In FIG. 18, V indicates a vertical scanning period.

  As shown in FIG. 18A, in order to correct NS pincushion distortion, a correction current that changes in a parabolic manner in a horizontal scanning cycle is superimposed on a sawtooth vertical deflection current VI that changes in a vertical scanning cycle. As described above, the polarity of the correction current am is inverted between the upper half and the lower half of the CRT tube surface. Accordingly, as shown in FIG. 18B, correction currents am having different polarities are superimposed on the upper half and the lower half of the vertical deflection current VI.

  Here, as shown in FIG. 18C, an HV crosstalk component CR that changes in the horizontal scanning period is generated in the vertical scanning period from the horizontal deflection coil to the vertical deflection coil. The polarity of the HV crosstalk component CR is the same within the vertical scanning period.

  Therefore, as shown in FIG. 18D, when the HV crosstalk component CR is combined with the correction current am, the peak of the correction current in the first half of the vertical scanning period is shifted to the left, and the correction current in the second half is corrected. The peak shifts to the right. Thereby, different image distortions occur in the upper half and the lower half of the CRT tube surface.

  The NS pincushion distortion generated by the combination of the deflection yoke and the CRT is ideally symmetrical, but the NS pincushion may not be symmetrical due to variations in various characteristics. Thereby, the horizontal line may not be displayed in a straight line on the CRT tube surface.

  FIG. 19 is a conceptual diagram for explaining correction of NS pincushion distortion. (A) shows NS pincushion distortion without correction on the CRT tube surface, (b) shows a correction waveform, and (c) shows The CRT tube surface at the time of correction is shown.

  When the NS pincushion distortion shown in FIG. 19 (a) is corrected using the parabolic correction waveform shown in FIG. 19 (b), the NS pincushion distortion can be linearly corrected as shown in FIG. 19 (c). it can.

  By the way, under the influence of FPD (flat panel display) typified by recent LCD (liquid crystal display device) and PDP (plasma display panel), there is an increasing demand for shortening the overall length of CRT.

  However, when the overall length of the CRT is shortened, NS pincushion distortion and EW pincushion distortion increase. The shape of the pincushion distortion in a CRT having a normal deflection angle shows a parabolic waveform characteristic (square characteristic), but a higher-order distortion component is generated in the pincushion distortion in a CRT having a large deflection angle such as a CRT having a reduced overall length. . In particular, with respect to NS pincushion distortion, a horizontal horizontal line becomes a pincushion and causes so-called gull wing distortion that deviates from a simple parabolic waveform characteristic (square characteristic).

  FIG. 20 is a conceptual diagram for explaining the occurrence of gull wing distortion. (A) shows NS pincushion distortion without correction on the CRT tube surface, (b) shows a correction waveform, and (c) shows correction. The CRT tube surface at the time is shown.

  When the NS pincushion distortion shown in FIG. 20 (a) is corrected using the parabolic correction waveform shown in FIG. 20 (b), a gull-wing distortion having higher-order distortion components shown in FIG. 20 (c) is generated.

  Here, FIG. 21 is a diagram showing a normalized waveform having a square waveform and a higher-order distortion component. The gull wing distortion is a difference between the square waveform of FIG. 21 and a waveform having a higher-order distortion component that is generated as distortion on the CRT tube surface.

  Thus, when the deflection angle of the CRT is increased, NS pincushion distortion cannot be corrected using the horizontal parabolic current of the square waveform.

  It is possible to add the harmonic component of the horizontal parabolic current (square component) to the vertical deflection current, but the inductance of the winding of the vertical deflection coil is on the order of several mH, and the resistance of the winding of the vertical deflection coil Since the component is on the order of several tens of Ω, the vertical deflection coil itself operates as a low-pass filter for components having a horizontal scanning frequency or higher. Therefore, when adding the harmonic components of the horizontal parabolic current, it is necessary to add a harmonic component that is considerably larger than the basic horizontal parabolic current to the vertical deflection current, and it is necessary to increase the circuit dynamic range. Occurs.

  Furthermore, in the conventional supersaturation reactor type NS pincushion distortion correction, since the horizontal parabolic current extracted from the horizontal deflection circuit is used, the horizontal parabolic current flows even in the vertical blanking period, and the power consumption is large.

  An object of the present invention is to provide a vertical deflection apparatus that can sufficiently correct upper and lower pincushion distortions without being affected by crosstalk from a horizontal deflection coil to a vertical deflection coil.

  Another object of the present invention is to provide a vertical deflection device capable of sufficiently correcting left and right asymmetrical upper and lower pincushion distortions.

  Still another object of the present invention is to provide a vertical deflection apparatus capable of sufficiently correcting NS pincushion distortion even when the deflection angle is large.

(1) First Invention A vertical deflection apparatus according to the first invention is a vertical deflection apparatus for supplying a vertical deflection current to a vertical deflection coil in order to deflect an electron beam in a vertical direction of a screen. A vertical deflection current output circuit that outputs a vertical deflection current, a correction circuit that outputs a correction signal that changes in a parabolic manner in the horizontal scanning period in order to correct upper and lower pincushion distortion, and a phase of the correction signal output by the correction circuit And a superimposing means for superimposing a correction current based on the output signal of the modulation circuit on the vertical deflection current. The correction circuit includes a parabolic waveform and other function waveforms that change in the horizontal scanning cycle. The other function waveform is a sine waveform, and the sine waveform has a period a / b times the horizontal scanning period and has a variable phase, and a and b are integer It is characterized by being.

  In the vertical deflection apparatus according to the present invention, the vertical deflection current is output to the vertical deflection coil by the vertical deflection current output circuit. In addition, a correction signal that changes in a parabolic manner in the horizontal scanning period is output in order to correct the upper and lower pincushion distortion by the correction circuit. Further, the phase of the correction signal output from the correction circuit is modulated by the modulation circuit in the vertical scanning period. The superimposing means superimposes a correction current based on the output signal of the modulation circuit on the vertical deflection current.

  In this case, the influence of the crosstalk component induced from the horizontal deflection coil to the vertical deflection coil is corrected by modulating the phase of the correction signal in the vertical scanning period. Thereby, the upper and lower pincushion distortion can be sufficiently corrected without being affected by the crosstalk.

  In particular, the combination of the parabolic waveform and the sine waveform can correct higher-order distortion components generated in the upper and lower pincushion distortions.

  In this case, higher-order strain components generated in the upper and lower pincushion strains can be corrected by arbitrarily setting the coefficient a, the coefficient b, and the phase.

(2) Second Invention In the vertical deflection apparatus according to the second invention, in the configuration of the vertical deflection apparatus according to the first invention, the modulation circuit delays the phase of the correction signal in the first half of the vertical scanning period to perform vertical scanning. The phase of the correction signal is advanced in the second half of the period.

  In this case, the crosstalk component is combined with the correction signal, so that the phase of the correction signal is advanced in the first half of the vertical scanning period, and the phase of the correction signal is delayed in the second half of the vertical scanning period. Therefore, the influence of the crosstalk component can be corrected by delaying the phase of the correction signal in the first half of the vertical scanning period and advancing the phase of the correction signal in the second half of the vertical scanning period.

(3) Third invention In the vertical deflection apparatus according to the third invention, in the configuration of the vertical deflection apparatus according to the first or second invention, the correction circuit sets the peak phase of the correction signal to the center of the horizontal scanning period. It has the function to shift from.

  This makes it possible to correct the left and right asymmetrical upper and lower pincushion distortions without being affected by crosstalk.

(4) Fourth invention A vertical deflection apparatus according to a fourth invention is the configuration of the vertical deflection apparatus according to any one of the first to third inventions, wherein the superimposing means includes the primary winding and the secondary winding. A transformer having a transformer and a drive circuit connected to the primary winding of the transformer, the secondary winding of the transformer being connected in series to the vertical deflection coil, and the drive circuit responding to the output signal of the combining means A drive current is supplied to the winding.

  In this case, a drive current is supplied to the primary winding of the transformer in accordance with the output signal of the combining means by the drive circuit. Thereby, the correction current based on the output signal of the combining means is superimposed on the vertical deflection current. In this way, the correction current can be easily superimposed on the vertical deflection current.

(5) Fifth Invention A vertical deflection apparatus according to a fifth invention is a vertical deflection apparatus according to any one of the first to fourth inventions, wherein a plurality of pulse generators generate pulse signals at a horizontal scanning period. And a combining unit that combines the pulse signals generated by the plurality of pulse generating circuits with the output signal of the modulation circuit, and the superimposing unit superimposes the correction current based on the output signal of the combining unit on the vertical deflection current. Is.

  In this case, the pulse component corresponding to the pulse signal in the correction current superimposed on the vertical deflection current is integrated by the vertical deflection coil. As a result, higher order distortion components generated in the upper and lower pincushion distortions are corrected by the integrated pulse components. Therefore, even when the deflection angle is large, the occurrence of gull wing distortion can be prevented and the upper and lower pincushion distortion can be sufficiently corrected without being affected by crosstalk.

(6) Sixth Invention The vertical deflection apparatus according to the sixth invention is the configuration of the vertical deflection apparatus according to the fifth invention, wherein the plurality of pulse generating circuits can independently control the peak values of the pulse signals. It is configured.

  Thereby, high-order distortion components of various sizes in the upper and lower pincushion distortion can be corrected.

(7) Seventh Invention A vertical deflection apparatus according to a seventh aspect of the invention is the vertical deflection apparatus according to the fifth or sixth aspect of the invention, wherein the plurality of pulse generation circuits each have a phase or a pulse width of the pulse signal. It is configured to be independently controllable.

  Thereby, it is possible to correct high-order distortion components having various phases or widths in the upper and lower pincushion distortion.

(8) Eighth Invention A vertical deflection apparatus according to an eighth invention is the vertical deflection apparatus according to any one of the fifth to seventh inventions, wherein the plurality of pulse generation circuits each change the polarity of the pulse signal. It is configured to be independently controllable.

  Thereby, it is possible to correct high-order distortion components having various polarities in the upper and lower pincushion distortion.

(9) Ninth Invention A vertical deflection apparatus according to a ninth aspect of the invention is the vertical deflection apparatus according to any one of the fifth to eighth aspects of the invention, wherein the modulation circuit outputs a correction signal output from the correction circuit. A first modulation circuit that modulates the crest value in a vertical scanning period, and the vertical deflection circuit includes a second modulation circuit that modulates the crest value of the pulse signal output by the plurality of pulse signal generation circuits in the vertical scanning period. In addition.

  In this case, the peak value of the correction signal output by the correction circuit is modulated by the first modulation circuit in the vertical scanning period, and the peak value of the pulse signal output by the plurality of pulse signal generation circuits is the second modulation. Modulated by a circuit with a vertical scanning period. Thereby, an optimal amount of correction can be performed in each part on the screen.

(10) Tenth Invention According to a tenth aspect of the present invention, in the vertical deflection apparatus according to any one of the fifth to ninth aspects, the combining means includes a correction signal output from the correction circuit and a correction signal. An adder for adding the pulse signals generated by the plurality of pulse signal generation circuits is included.

  In this case, the pulse signal and the correction signal are synthesized by adding the correction signal output from the correction circuit by the adder and the pulse signals generated by the plurality of pulse signal generation circuits.

(11) Eleventh Invention A vertical deflection apparatus according to an eleventh aspect of the invention is the blanking for setting the correction current to zero during the vertical blanking period in the configuration of the vertical deflection apparatus according to any one of the first to tenth inventions. A circuit is further provided.

  In this case, since the correction current becomes 0 in the vertical blanking period, power saving can be achieved.

  According to the present invention, the influence of the crosstalk component induced from the horizontal deflection coil to the vertical deflection coil is corrected by modulating the phase of the correction signal in the vertical scanning period. Thereby, the upper and lower pincushion distortion can be sufficiently corrected without being affected by the crosstalk.

  In particular, the combination of the parabolic waveform and the sine waveform can correct higher-order distortion components generated in the upper and lower pincushion distortions.

  In this case, higher-order strain components generated in the upper and lower pincushion strains can be corrected by arbitrarily setting the coefficient a, the coefficient b, and the phase.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(1) First Embodiment FIG. 1 is a block diagram showing a configuration of a vertical deflection apparatus according to a first embodiment of the present invention. FIG. 2 is a signal waveform diagram of each part of the vertical deflection apparatus of FIG. In FIG. 2, V indicates a vertical scanning period, and H indicates a horizontal scanning period.

  In the vertical deflection apparatus of FIG. 1, the vertical amplifier 1, the vertical deflection coil 2, the vertical current detection resistor 3, the vertical feedback circuit 4, and the secondary winding of the transformer 6 constitute a vertical output circuit 5. The sawtooth voltage SW that changes in the vertical scanning cycle is applied to the input terminal of the vertical amplifier 1. Between the output terminal of the vertical amplifier 1 and the ground terminal, the vertical deflection coil 2, the secondary winding of the transformer 6, and the vertical current detection resistor 3 are connected in series. A connection point between the secondary winding of the transformer 6 and the vertical current detection resistor 3 is connected to an input terminal of the vertical amplifier 1 through a vertical feedback circuit 4.

  The output terminal of the correction current output amplifier 7 is connected to one end of the primary winding of the transformer 6. The other end of the primary winding of the transformer 6 is connected to the ground terminal via the correction current detection resistor 8. One input terminal of the correction current output amplifier 7 is supplied with a modulated horizontal parabolic signal HP1 described later. The connection point between the other end of the primary winding of the transformer 6 and the correction current detection resistor 8 is connected to the other input terminal of the correction current output amplifier 7 via the NS pincushion distortion feedback circuit 9.

  The vertical modulation signal generation circuit 31 generates a vertical modulation signal (vertical modulation voltage) VM. As shown in FIG. 2A, the vertical modulation signal VM changes in a sawtooth shape with a vertical scanning period. The horizontal parabolic signal generation circuit 32 generates a horizontal parabolic signal (horizontal parabolic voltage) HP. As shown in FIG. 2B, the horizontal parabolic signal HP changes in a parabolic manner in the horizontal scanning period.

  In a vertical scanning period horizontal parabola modulation circuit (hereinafter abbreviated as a parabola modulation circuit) 12, a vertical modulation signal VM generated by a vertical modulation signal generation circuit 31 and a horizontal parabola signal HP generated by a horizontal parabola signal generation circuit 32 are provided. Is given. The parabola modulation circuit 12 multiplies the horizontal parabola signal HP and the vertical modulation signal VM to amplitude-modulate the horizontal parabola signal HP with the vertical modulation signal VM, and modulates the phase of the horizontal parabola signal HP based on the vertical modulation signal VM. Then, the modulated horizontal parabolic signal HP 1 is output to one input terminal of the correction current output amplifier 7. As shown in FIG. 2C, in the first half of the vertical scanning period, the polarity of the horizontal parabolic signal HP1 is not inverted, and the amplitude of the horizontal parabolic signal HP1 gradually decreases according to the level of the vertical modulation signal VM. In the second half of the period, the polarity of the horizontal parabolic signal HP1 is inverted, and the amplitude of the horizontal parabolic signal HP1 gradually increases according to the level of the vertical modulation signal VM.

  FIG. 3 is a waveform diagram for explaining NS pincushion distortion correction in the vertical deflection apparatus of FIG.

  3A shows the horizontal parabolic signal HP output from the horizontal parabolic signal generating circuit 32, and FIG. 3B shows the current (HV crosstalk component) CR induced from the horizontal deflection coil to the vertical deflection coil. 3C shows a composite waveform of the horizontal parabolic signal HP in FIG. 3A and the HV crosstalk component CR in FIG. 3B, and FIG. 3D is modulated by the parabolic modulation circuit 12. FIG. The horizontal parabolic signal HP1 is shown, and FIG. 3E shows a combined waveform of the horizontal parabolic signal HP1 shown in FIG. 3D and the HV crosstalk component CR shown in FIG.

  As shown in FIG. 3A, the horizontal parabolic signal generation circuit 32 outputs a horizontal parabolic signal HP that changes in the horizontal scanning period. As shown in FIG. 3B, the HV crosstalk component CR changes with the horizontal scanning period.

  The horizontal parabolic signal HP in FIG. 3A and the HV crosstalk component CR in FIG. 3B are combined (added). Thereby, as shown in FIG. 3C, the phase of the synthesized waveform advances in the horizontal scanning period at the upper part of the tube surface, and the phase of the synthesized waveform is delayed in the horizontal scanning period at the lower part of the tube surface. . That is, the synthesized waveform peak shifts to the left in the horizontal direction at the upper portion of the tube surface, and the synthesized waveform peak shifts to the right in the horizontal direction at the lower portion of the tube surface.

  The parabolic modulation circuit 12 of FIG. 1 delays the phase of the horizontal parabolic signal HP at the upper part of the tube surface, and advances the phase of the horizontal parabolic signal HP at the lower portion of the tube surface. Thereby, as shown in FIG. 3 (d), the peak of the modulated horizontal parabolic signal HP1 shifts to the right in the horizontal direction at the upper part of the tube surface, and the peak of the modulated horizontal parabolic signal HP1 at the lower part of the tube surface. Shifts to the left in the horizontal direction.

  As shown in FIG. 3 (e), the horizontal parabolic signal HP1 in FIG. 3 (d) and the HV crosstalk CR in FIG. 3 (b) are combined (added), and as shown in FIG. The peak of the synthesized waveform is located at the center in the horizontal direction.

  In this way, the parabolic modulation circuit 12 outputs the corrected horizontal parabolic signal HP1. The horizontal parabolic signal HP1 output from the parabolic modulation circuit 12 is amplified by the correction current output amplifier 7, and the correction current am0 output from the correction current output amplifier 7 flows through the primary winding of the transformer 6.

  The vertical amplifier 1 outputs a sawtooth vertical deflection current VI that changes in the vertical scanning period in response to the sawtooth voltage SW that changes in the vertical scanning period. A correction current am1 is obtained in the secondary winding by the current flowing in the primary winding of the transformer 6. The correction current am1 changes in a parabolic manner in the horizontal scanning period, similarly to the combined waveform shown in FIG. The correction current am1 is superimposed on the vertical deflection current VI output from the vertical amplifier 1. Thereby, NS pincushion distortion is corrected without being affected by HV crosstalk.

  Next, NS pincushion distortion will be described with reference to FIG. 4 in the case where the distortion differs on the left and right in the horizontal direction of the tube surface depending on the combination of the CRT and the deflection yoke. FIG. 4 is a diagram for explaining a horizontal parabolic signal when the NS pincushion distortion is symmetric on the tube surface and a horizontal parabolic signal when the NS pincushion distortion is asymmetrical on the tube surface.

  FIG. 4A shows a horizontal line displayed on the tube surface when the NS pincushion distortion on the CRT tube surface is symmetric due to the combination of the CRT and the deflection yoke. As shown in FIG. 4A, when the NS pincushion distortion on the CRT pipe surface is symmetric, as shown in FIG. 4C, a symmetric horizontal parabolic signal HP is generated. The horizontal parabolic signal generation circuit 32 of FIG. 1 is set.

  FIG. 4B shows a horizontal line displayed on the tube surface when NS pincushion distortion on the CRT tube surface is asymmetrical due to the combination of the CRT and the deflection yoke. As shown in FIG. 4 (b), when the NS pincushion distortion on the CRT tube surface is asymmetrical, as shown in FIG. 4 (d), a horizontal parabolic signal HP that is asymmetrical is generated. The horizontal parabolic signal generation circuit 32 of FIG. 1 is set.

  FIG. 5 is a block diagram showing a reference example of the configuration of the horizontal parabolic signal generation circuit 32. FIG. 6 is a waveform diagram for explaining the operation of the horizontal parabolic signal generation circuit 32 of FIG. In FIG. 6A, BR represents a horizontal blanking period. In FIGS. 6B, 6C, and 6D, the display of the horizontal blanking period is omitted.

  As shown in FIG. 5, the horizontal parabolic signal generation circuit 32 includes a horizontal broken line sawtooth wave generator 321, a folded waveform generator 322, and an n-th power waveform generator 323. The horizontal broken line sawtooth wave generator 321 generates a horizontal broken line sawtooth wave HS that changes in the horizontal scanning cycle. The folded waveform generator 322 generates a horizontal folded waveform RT based on the horizontal broken line sawtooth wave HS. The n-th power waveform generator 323 generates the horizontal parabolic signal HP by shifting the peak of the n-th power waveform based on the horizontal folded waveform RT.

  As shown in FIG. 6A, in the horizontal line sawtooth wave HS generated by the horizontal line sawtooth wave generator 321, the point PO whose amplitude is ½ can be moved back and forth from the center of the horizontal scanning period. it can. Accordingly, the horizontal broken line sawtooth wave HS is bent at a point PO having an amplitude of ½, and the period before and after the point PO changes. In FIG. 6A, the horizontal broken line saw wave HS is shown by a thick line when the point PO having the amplitude 1/2 is shifted from the center of the horizontal scanning period, and the point PO having the amplitude 1/2 is at the center of the horizontal scanning period. A horizontal broken line sawtooth HS in a certain case is indicated by a thin line. In FIG. 6A, in order to emphasize that the horizontal broken-line saw wave HS is bent at a point PO having an amplitude of 1/2, the horizontal broken-line saw wave HS indicated by a thin line has a phase indicated by a thick line. Although it is expressed so as to be shifted by ΔT with respect to the phase of the wave HS, in practice, the phase of the horizontal polygonal sawtooth wave HS indicated by a thin line coincides with the phase of the horizontal polygonal sawtooth wave HS indicated by a thick line.

  As shown in FIG. 6B, the latter half of the folded waveform RT generated by the folded waveform generator 322 is folded upward at a point PO having an amplitude of 1/2. Also in FIG. 6B, in order to emphasize that the folded waveform RT is folded at a point having an amplitude of ½, the phase of the folded waveform RT indicated by a thin line is changed to the phase of the folded waveform RT indicated by a thick line. On the other hand, it is represented so as to be shifted by ΔT. Actually, as shown in FIG. 6C, the phase of the folded waveform RT indicated by the thin line coincides with the phase of the folded waveform RT indicated by the thick line, and the phase of the folded point of the folded waveform RT indicated by the thin line is It is shifted by ΔT with respect to the phase of the turning point of the turning waveform RT indicated by the bold line.

  The horizontal parabolic signal HP is generated by the n-th power waveform generator 323 raising the horizontal folded waveform RT to the nth power. As shown in FIG. 6D, the peak phase P2 of the horizontal parabolic signal HP indicated by the thick line is shifted by ΔT with respect to the peak phase P1 of the horizontal parabolic signal HP indicated by the thin line.

  Note that n in the n-th power generator 323 is a positive real number, and the n-th power generated by the n-th power generator 323 is set to a square when the gull-wing distortion described later does not occur.

  In this way, the horizontal parabolic signal generation circuit 32 can generate the horizontal asymmetric horizontal parabolic signal HP shown in FIG. As a result, NS pincushion distortion that is asymmetrical on the tube surface caused by the combination of the CRT and the deflection yoke can be corrected.

  Next, correction of gull wing distortion that occurs when the deflection angle of the CRT is increased will be described with reference to FIG. As shown in FIG. 20, since the gull wing distortion does not have a parabolic waveform, it cannot be corrected by the horizontal parabolic signal HP having a simple parabolic waveform.

FIG. 7 is a waveform diagram showing an n-th power waveform used for correction of gull wing distortion. In FIG. 7, the nth power waveform is represented by Y = ^Xn , and the nth power waveform in the case of n = 1.2, n = 1.5, n = 2, and n = 4 is shown. Here, Y is the amplitude of the waveform, and X is the position in the horizontal direction.

As shown in FIG. 7, in the n-th power waveform represented by Y = ^Xn , when n is changed, the amplitude at the position of 1/2 of one cycle does not change, and the position of 1/4 of one cycle. And the amplitude changes at the position of 3/4. Therefore, when the length in the horizontal direction on the CRT tube surface is 1, the correction amounts of the 1/4 position and the 3/4 position change according to n. Therefore, the gull wing distortion can be corrected by adjusting the value of n.

  In the horizontal parabolic signal generation circuit 32 of FIG. 5, the gull wing distortion can be corrected by adjusting the value of n in the n-th power waveform generator 323.

  The gull wing distortion may be corrected by combining a plurality of n-th power waveforms in the horizontal parabolic signal generation circuit 32. In this case, the waveform of the horizontal parabolic signal HP is expressed by the following equation.

Y = A _n1 X ⁿ¹ + A _n2 X ⁿ² + ... + A _nk X ^nk
In the above equation, n1, n2,..., Nk are arbitrary positive real numbers, and A _n1 , A _{n2 ,.}

  For example, the waveform of the horizontal parabolic signal HP may be set as follows:

Y = AX ² + BX ⁴
In the above equation, A and B are arbitrary coefficients. The gull-wing distortion can be corrected by adjusting the coefficients A and B in the horizontal parabolic signal generation circuit 32.

  FIG. 8 is a block diagram showing an example of the configuration of the horizontal parabolic signal generation circuit 32. FIG. 9 is a waveform diagram for explaining the operation of the horizontal parabolic signal generation circuit 32 of FIG.

  As shown in FIG. 8, the horizontal parabolic signal generation circuit 32 includes a parabolic waveform generator 331, a combiner 332, and a sine wave generator 333. The parabolic waveform generator 331 generates a parabolic waveform PA that changes in the horizontal scanning period in the same manner as the horizontal broken line sawtooth wave generator 321, the folded waveform generator 322, and the n-th power waveform generator 323 in FIG. The sine wave generator 333 generates a sine wave SI that changes in the horizontal scanning cycle. The combiner 332 combines the parabolic waveform PA generated by the parabolic waveform generator 331 and the sine wave SI generated by the sine wave generator 333, and outputs a horizontal parabolic signal HP.

As shown in FIG. 9 (a), the parabolic waveform PA generated by the parabolic waveform generator 331 is represented by Y = X ^2. As shown in FIG. 9B, the sine wave SI generated by the sine wave generator 333 is represented by Y = sin [(2πfh · b / a) X + θ]. Here, fh is a horizontal scanning frequency, and a and b are arbitrary coefficients. For example, b / a = 4/3. Θ is an adjustable phase. Therefore, the sine wave SI has a period a / b times the horizontal scanning period, and the phase θ can be adjusted.

As shown in FIG. 9C, the horizontal parabolic signal HP output from the combiner 332 is represented by Y = X ² + sin [(2πfh · b / a) X + θ].

  FIG. 9D shows a comparison between the parabolic waveform PA generated by the parabolic waveform generator 331 and the horizontal parabolic signal HP output from the combiner 332. By synthesizing (adding) the sine wave SI to the parabolic waveform PA, the amplitude of the peak position (center portion) of the parabolic waveform can be increased, and the amplitudes on both sides of the peak can be decreased.

  Therefore, the gull-wing distortion can be corrected by adjusting the coefficients a and b or the phase θ in the horizontal parabolic signal generation circuit 32.

  As described above, the vertical deflection apparatus according to the present embodiment can correct NS pincushion distortion having higher-order distortion components generated by the combination of the full length shortening CRT and the deflection yoke without being affected by HV crosstalk. It becomes possible. In addition, it is possible to correct NS distortion that is asymmetrical. Furthermore, even when the deflection angle is large, the occurrence of gull wing distortion can be prevented and the occurrence of NS pincushion distortion can be sufficiently corrected.

  In this case, if the correction current detection resistor 8, NS pincushion distortion feedback circuit 9, parabola modulation circuit 12, vertical modulation signal generation circuit 31, horizontal parabola signal generation circuit 32, etc. are integrated into an IC (integrated circuit), such an IC, The NS pincushion distortion can be corrected only by the transformer 6 and the correction current output amplifier 7, and the NS pincushion distortion can be corrected at low cost.

  In the present embodiment, the vertical amplifier 1 corresponds to a vertical deflection current output circuit, the horizontal parabolic signal generation circuit 32 corresponds to a correction circuit, the parabolic modulation circuit 12 corresponds to a modulation circuit, the transformer 6 and the correction current output amplifier. 7 corresponds to superimposing means.

(2) Second Embodiment FIG. 10 is a block diagram showing a configuration of a vertical deflection apparatus according to a second embodiment of the present invention. The vertical deflection apparatus of the present embodiment has a configuration for power saving.

  In the vertical deflection apparatus of FIG. 10, a vertical blanking circuit 35 is further added to the configuration of the vertical deflection apparatus of FIG. The vertical blanking circuit 35 corresponds to a blanking circuit.

  The vertical blanking circuit 35 is supplied with the vertical blanking signal VB and the horizontal parabolic signal HP from the horizontal parabolic signal generating circuit 32. The vertical blanking circuit 35 sets the level of the horizontal parabola signal HP in the vertical blanking period to 0 based on the vertical blanking signal VB, and the horizontal parabola signal whose level in the vertical blanking period is 0 (hereinafter, vertical blanking is performed). HPb is generated (referred to as a horizontal parabolic signal). The vertically blanked horizontal parabolic signal HPb is output to the parabolic modulation circuit 12.

  The parabola modulation circuit 12 multiplies the vertical blanked horizontal parabola signal HPb and the vertical modulation signal VM to amplitude-modulate the horizontal parabola signal HPb with the vertical modulation signal VM, and based on the vertical modulation signal VM, the horizontal parabola signal The phase of HPb is modulated, and the modulated horizontal parabolic signal HP 2 is output to one input terminal of the correction current output amplifier 7.

  The horizontal parabolic signal HP2 output from the parabolic modulation circuit 12 is amplified by the correction current output amplifier 7, and the correction current ami0 output from the correction current output amplifier 7 flows through the primary winding of the transformer 6.

  A correction current ami1 is obtained in the secondary winding by the current flowing in the primary winding of the transformer 6. The correction current ami1 is superimposed on the vertical deflection current VI output from the vertical amplifier 1. Thereby, NS pincushion distortion is corrected without being affected by HV crosstalk.

  FIG. 11 is a waveform diagram of the vertical deflection current, the correction current, the vertical blanked correction current, and the vertical blanking signal in the vertical deflection apparatus of FIG. In FIG. 11, the waveforms of the correction current and the vertically blanked correction current are schematically shown.

  As shown in FIG. 11, when the correction current am1 is superimposed on the vertical deflection current VI, the correction current am1 flows even in the vertical blanking period when there is no image.

  In the present embodiment, the value of the correction current ami1 is set to 0 in the vertical blanking period based on the vertical blanking signal VB. Thereby, it is possible to save power in the correction current output amplifier 7 in the vertical blanking period.

  Therefore, in the vertical deflection apparatus of this embodiment, even when the deflection angle is large, the occurrence of gull-wing distortion can be prevented and the occurrence of NS pincushion distortion can be sufficiently corrected without being affected by HV crosstalk. In addition, power saving can be achieved.

(3) Third Embodiment FIG. 12 is a block diagram showing a configuration of a vertical deflection apparatus in the third embodiment of the present invention.

  In the vertical deflection apparatus of FIG. 12, the vertical amplifier 1, the vertical deflection coil 2, the vertical current detection resistor 3, the vertical feedback circuit 4, and the secondary winding of the transformer 6 constitute a vertical output circuit 5. The sawtooth voltage SW that changes in the vertical scanning cycle is applied to the input terminal of the vertical amplifier 1. Between the output terminal of the vertical amplifier 1 and the ground terminal, the vertical deflection coil 2, the secondary winding of the transformer 6, and the vertical current detection resistor 3 are connected in series. A connection point between the secondary winding of the transformer 6 and the vertical current detection resistor 3 is connected to an input terminal of the vertical amplifier 1 through a vertical feedback circuit 4.

  The output terminal of the correction current output amplifier 7 is connected to one end of the primary winding of the transformer 6. The other end of the primary winding of the transformer 6 is connected to the ground terminal via the correction current detection resistor 8. An output signal AD of an adder 14 described later is given to one input terminal of the correction current output amplifier 7. The connection point between the other end of the primary winding of the transformer 6 and the correction current detection resistor 8 is connected to the other input terminal of the correction current output amplifier 7 via the NS pincushion distortion feedback circuit 9.

  The parabola modulation circuit 12 is supplied with the vertical modulation signal VM generated by the vertical modulation signal generation circuit 31 and the horizontal parabola signal HP generated by the horizontal parabola signal generation circuit 32. The parabola modulation circuit 12 multiplies the horizontal parabola signal HP by the vertical modulation signal VM to amplitude-modulate the horizontal parabola signal HP with the vertical modulation signal VM, and the modulated horizontal parabola signal HP1 is input to one input of the adder 7. Output to the terminal. As shown in FIG. 2C, in the first half of the vertical scanning period, the polarity of the horizontal parabolic signal HP1 is not inverted, and the amplitude of the horizontal parabolic signal HP1 gradually decreases according to the level of the vertical modulation signal VM. In the second half of the scanning period, the polarity of the horizontal parabolic signal HP1 is inverted, and the amplitude of the horizontal parabolic signal HP1 gradually increases according to the level of the vertical modulation signal VM.

  The parabolic modulation circuit 12 in FIG. 12 may modulate the phase of the horizontal parabolic signal HP based on the vertical modulation signal VM, similarly to the parabolic modulation circuit 12 in FIG. Thereby, NS pincushion distortion can be corrected without being affected by the HV crosstalk component.

  The vertical deflection apparatus in FIG. 12 includes a plurality of pulse generators 18. In the present embodiment, two pulse generators 18 are provided. Each pulse generator 18 includes a pulse peak value control circuit 15, a pulse polarity control circuit 16, and a pulse generation phase control circuit 17. The pulse generation phase control circuit 17 generates a pulse signal at a horizontal scanning period and controls the phase or pulse width of the pulse signal. The pulse polarity control circuit 16 controls the polarity of the pulse signal generated by the pulse generation phase control circuit 17. The pulse peak value control circuit 15 controls the peak value of the pulse signal output by the pulse polarity control circuit 16. The pulse generation phase control circuit 17 of each pulse generator 18 controls the phase or pulse width of the pulse signal independently. The pulse polarity control circuit 16 of each pulse generator 18 controls the polarity of the pulse signal independently. Further, the pulse peak value control circuit 15 of each pulse generator 18 independently controls the peak value of the pulse signal.

  A vertical modulation signal VM and pulse signals P1 and P2 generated by a plurality of pulse generators 18 are applied to a vertical scanning period pulse modulation circuit (hereinafter abbreviated as pulse modulation circuit) 13. The pulse modulation circuit 13 modulates the pulse signals P1 and P2 provided by the plurality of pulse generators 18 with the vertical modulation signal VM, and supplies the modulated pulse signals P1a and P2a to the other input terminal of the adder 14.

  The adder 14 adds the horizontal parabolic signal HP1 given by the parabolic modulation circuit 12 and the pulse signals P1a and P2a given by the pulse modulation circuit 13, and outputs an output signal AD indicating the addition result to one of the correction current output amplifiers 7. To the input terminal. Here, the parabolic modulation circuit 12 outputs the polarity of the horizontal parabolic signal HP as it is in the first half of the sawtooth wave portion of the vertical modulation signal VM, and gradually decreases the amplitude of the horizontal parabolic signal HP at the level of the sawtooth wave. The polarity of the horizontal parabolic signal HP is inverted at the latter half of the sawtooth wave of the signal VM, and the amplitude of the horizontal parabolic signal HP is gradually increased at the level of the sawtooth wave.

  In the present embodiment, the pulse generator 18 shown in FIG. 12 is used to correct the difference between the square waveform shown in FIG. 21 and the waveform having a higher-order distortion component.

  The configuration and operation of the horizontal parabolic signal generation circuit 32 in FIG. 12 are the same as the configuration and operation of the horizontal parabolic signal generation circuit 32 in FIG. However, in the vertical deflection apparatus of the present embodiment, the gull wing distortion is corrected by the pulse modulation circuit 13, the adder 14, and the pulse generation unit 18 as will be described later, so that the horizontal parabolic signal generation circuit 32 has a gull wing distortion correction function. It is not necessary to have.

  FIG. 13 is a waveform diagram for explaining NS pincushion distortion correction in the vertical deflection apparatus of FIG.

  13A shows the horizontal parabolic signal HP1 output from the parabolic modulation circuit 12, FIG. 13B shows the pulse signals P1a and P2a output from the pulse modulation circuit 13, and FIG. 13C shows the addition. FIG. 13 (d) shows the correction current AM1 flowing through the vertical deflection coil 2. FIG.

  As shown in FIG. 13A, the parabolic modulation circuit 12 outputs a horizontal parabolic signal HP1 having a square waveform modulated by the vertical modulation signal VM. As shown in FIG. 13B, the pulse modulation circuit 13 outputs pulse signals P1a and P2a modulated by the vertical modulation signal VM.

  As shown in FIG. 13 (c), the adder 14 adds the horizontal parabolic signal HP1 in FIG. 13 (a) and the pulse signals P1a and P2a in FIG. 13 (b), and outputs an output signal AD indicating the addition result. Is done.

  Further, the output signal AD of the adder 14 is amplified by the correction current output amplifier 7, and the correction current AM output from the correction current output amplifier 7 flows through the primary winding of the transformer 6. The current generated in the secondary winding by the current flowing in the primary winding of the transformer 6 is integrated by the vertical deflection coil 2. As a result, the pulse component is integrated, and a correction current AM1 shown in FIG. 13D for correcting the higher-order distortion component is obtained. This prevents the occurrence of gull wing distortion shown in FIG.

  As described above, since the pulse generator 18 of FIG. 12 includes the pulse generation phase control circuit 17, the pulse polarity control circuit 16, and the pulse peak value control circuit 15, the phases of the pulse signals P1a and P2a, and the pulse signals P1a and P2a , The peak values of the pulse signals P1a and P2a, and the polarities of the pulse signals P1a and P2a can be changed. Therefore, it is possible to correct high-order distortion components having various sizes, widths, and polarities.

  In the example of FIG. 13, negative pulse signals P1a and P2a are shown. However, when a positive pulse signal is generated from the pulse generator 18, the broken line portion of the correction current AM1 in FIG. The shape is convex upward.

  In the present embodiment, the case where two sets of pulse generators 18 are used has been described. However, the distortion of the vertical deflection current VI due to local distortion of the vertical deflection coil 2 is also the third or fourth pulse. Correction can be made by preparing the generator.

  As described above, in the vertical deflection apparatus of the present embodiment, even when the deflection angle is large, the occurrence of gull wing distortion can be prevented and NS pincushion distortion can be sufficiently corrected. Further, it is possible to correct NS pincushion distortion having higher-order distortion components generated by the combination of the full length shortening CRT and the deflection yoke without being affected by HV crosstalk. Furthermore, it is possible to correct NS distortion that is asymmetrical.

  In this case, if the correction current detection resistor 8, NS pincushion distortion feedback circuit 9, parabolic modulation circuit 12, pulse modulation circuit 13, adder 14, multiple pulse generators 18, etc. are integrated into an IC (integrated circuit), NS pincushion distortion can be corrected only by the IC, the transformer 6 and the correction current output amplifier 7, and NS pincushion distortion can be corrected at low cost.

  In the present embodiment, the vertical amplifier 1 corresponds to a vertical deflection current output circuit, the horizontal parabolic signal generation circuit 32 corresponds to a correction circuit, the parabolic modulation circuit 12 corresponds to a modulation circuit, and the pulse generator 18 generates pulses. Corresponds to a circuit. Further, the adder 14 corresponds to a combining unit, and the transformer 6 and the correction current output amplifier 7 correspond to a superimposing unit. Further, the parabolic modulation circuit 12 corresponds to a first modulation circuit, and the pulse modulation circuit 13 corresponds to a second modulation circuit.

(4) Fourth Embodiment FIG. 14 is a block diagram showing a configuration of a vertical deflection apparatus in the fourth embodiment of the present invention. The vertical deflection apparatus of the present embodiment has a configuration for power saving.

  In the vertical deflection apparatus of FIG. 14, a vertical blanking circuit 19 indicated by a dotted line is further added to the configuration of the vertical deflection apparatus of FIG. The vertical blanking circuit 19 corresponds to a blanking circuit.

  The vertical blanking circuit 19 is supplied with the vertical blanking signal VB and the output signal AD of the adder 14. The output signal AD1 of the vertical blanking circuit 19 is given to one input terminal of the correction current output amplifier 7.

  FIG. 15 is a waveform diagram of the vertical deflection current, the correction current, the vertical blanked correction current, and the vertical blanking signal in the vertical deflection apparatus of FIG. In FIG. 15, the waveforms of the correction current and the vertically blanked correction current are schematically shown.

  As shown in FIG. 15, when the correction current AM is superimposed on the vertical deflection current VI, the correction current AM flows even in the vertical blanking period when there is no image.

  In the present embodiment, the value of the correction current AMI is set to 0 in the vertical blanking period based on the vertical blanking signal VB. Thereby, it is possible to save power in the correction current output amplifier 7 in the vertical blanking period.

  Therefore, in the vertical deflection apparatus of the present embodiment, even when the deflection angle is large, the occurrence of gull wing distortion can be prevented, and NS pincushion distortion can be sufficiently corrected without being affected by HV crosstalk. Power saving can be achieved.

  The vertical deflection devices of the first to fourth embodiments have a function of correcting HV crosstalk, a function of correcting left-right asymmetric NS pincushion distortion, and a function of correcting gull wing distortion. The vertical deflection device may have one or two of these functions.

  The present invention can be used for a video display device such as a television receiver and a monitor device using a CRT.

The block diagram which shows the structure of the vertical deflection | deviation apparatus in the 1st Embodiment of this invention. Signal waveform diagram of each part of the vertical deflection apparatus of FIG. The figure for demonstrating NS pincushion distortion correction in the vertical deflection | deviation apparatus of FIG. The figure for demonstrating the horizontal parabolic signal in case NS pincushion distortion is symmetrical on the pipe surface, and the horizontal parabola signal in case NS pincushion distortion is asymmetrical on the pipe surface. Block diagram showing a reference example of the configuration of a horizontal parabolic signal generation circuit Waveform diagram for explaining the operation of the horizontal parabolic signal generation circuit of FIG. Waveform diagram showing n-th power waveform used for correction of gull wing distortion Block diagram showing an example of the configuration of a horizontal parabolic signal generation circuit Waveform diagram for explaining the operation of the horizontal parabolic signal generation circuit of FIG. The block diagram which shows the structure of the vertical deflection | deviation apparatus in the 2nd Embodiment of this invention. Waveform diagram of vertical deflection current, correction current, correction current with vertical blanking and vertical blanking signal in the vertical deflection apparatus of FIG. The block diagram which shows the structure of the vertical deflection | deviation apparatus in the 3rd Embodiment of this invention. Waveform diagram for explaining NS pincushion distortion correction in the vertical deflection apparatus of FIG. The block diagram which shows the structure of the vertical deflection | deviation apparatus in the 4th Embodiment of this invention. 14 is a waveform diagram of the vertical deflection current, the correction current, the correction current subjected to vertical blanking, and the vertical blanking signal in the vertical deflection apparatus of FIG. (A) The figure which shows the example of NS pincushion distortion on the CRT tube surface, and (b) The figure which shows NS pincushion distortion correction current superimposed on the vertical deflection current Schematic showing NS pincushion distortion correction by a conventional supersaturated reactor system Diagram for explaining HV crosstalk Conceptual diagram for explaining correction of NS pincushion distortion Conceptual diagram for explaining the occurrence of gullwing distortion Diagram showing normalized waveforms with squared waveforms and higher-order distortion components

Explanation of symbols

1 vertical amplifier 2 vertical deflection coil 3 vertical current detection resistor 4 vertical feedback circuit 5 vertical output circuit 6 transformer 7 correction current output amplifier 8 correction current detection resistor 9 NS pincushion distortion feedback circuit 12 vertical scanning period horizontal parabola modulation circuit 13 vertical scanning period Pulse modulation circuit 14 Adder 15 Pulse peak value control circuit 16 Pulse polarity control circuit 17 Pulse generation phase control circuit 18 Pulse generation unit 19, 35 Vertical blanking circuit 31 Vertical modulation signal generation circuit 32 Horizontal parabolic signal generation circuit VI Vertical deflection current HP Horizontal parabolic signal HP1, HP2 Modulated horizontal parabolic signal am0, am1, am0, ami1, AM, AM1, AMI, AMI1, Correction current VM Vertical modulation signal P1, P2, P1a, P2a Pulse signal VB Vertical blanking Issue

Claims (11)

A vertical deflection device for supplying a vertical deflection current to a vertical deflection coil to deflect an electron beam in a vertical direction of a screen,
A vertical deflection current output circuit for outputting a vertical deflection current to the vertical deflection coil;
A correction circuit that outputs a correction signal that changes in a parabolic manner in a horizontal scanning period in order to correct upper and lower pincushion distortion;
A modulation circuit that modulates the phase of the correction signal output by the correction circuit in a vertical scanning period;
Superimposing means for superimposing a correction current based on an output signal of the modulation circuit on a vertical deflection current;
The correction circuit outputs the correction signal by a combination of a parabolic waveform changing in a horizontal scanning cycle and another function waveform,
The other function waveform is a sine waveform,
2. The vertical deflection apparatus according to claim 1, wherein the sine waveform has a period a / b times a horizontal scanning period and a variable phase, and a and b are integers. 2. The vertical deflection apparatus according to claim 1, wherein the modulation circuit delays the phase of the correction signal in the first half of the vertical scanning period and advances the phase of the correction signal in the second half of the vertical scanning period. The vertical deflection apparatus according to claim 1, wherein the correction circuit has a function of shifting a phase of a peak of the correction signal from a center of a horizontal scanning period. The superimposing means includes
A transformer having a primary winding and a secondary winding;
A drive circuit connected to the primary winding of the transformer,
A secondary winding of the transformer is connected in series to the vertical deflection coil;
The vertical deflection apparatus according to claim 1, wherein the drive circuit supplies a drive current to a primary winding of the transformer in accordance with an output signal of the synthesizing unit. A plurality of pulse generation circuits for generating a pulse signal in a horizontal scanning cycle;
A synthesis means for synthesizing the pulse signals generated by the plurality of pulse generation circuits with the output signal of the modulation circuit;
5. The vertical deflection apparatus according to claim 1, wherein the superimposing unit superimposes a correction current based on an output signal of the synthesizing unit on a vertical deflection current. 6. The vertical deflection apparatus according to claim 5, wherein the plurality of pulse generation circuits are configured to be capable of independently controlling the peak values of the pulse signals. 7. The vertical deflection apparatus according to claim 5, wherein the plurality of pulse generation circuits are configured to be capable of independently controlling a phase or a pulse width of a pulse signal. 8. The vertical deflection apparatus according to claim 5, wherein the plurality of pulse generation circuits are configured to be capable of independently controlling the polarity of the pulse signal. The modulation circuit includes a first modulation circuit that modulates a peak value of a correction signal output from the correction circuit in a vertical scanning period;
9. The vertical deflection according to claim 5, further comprising a second modulation circuit that modulates a peak value of a pulse signal output from the plurality of pulse signal generation circuits in a vertical scanning period. circuit. The adder that adds the correction signal output from the correction circuit and the pulse signals generated by the plurality of pulse generation circuits is included in the synthesizing unit. Vertical deflection device. The vertical deflection apparatus according to claim 1, further comprising a blanking circuit that sets the correction current to 0 during a vertical blanking period.

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