JP2001061159A - Color cathode-ray tube display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct accurate landing correction at all times by measuring the value required for the landing correction. SOLUTION: In this color cathode ray tube display device, signals from photosensors 6a-6h detecting the emission intensity of phosphors of a color cathode-ray tube are amplified by current-voltage conversion amplifiers 7a-7h, respectively, and the amplified signals are fed to a signal changeover circuit 8, the selected signal therein is fed to a signal processing circuit 9, and the processed signal is fed to correction waveform generating circuits 21, 22, 23, which generate a correction signal changed with horizontal scanning periods of, e.g. a prescribed number in synchronism with the vertical scanning period. The correction signals generated by the correction waveform generating circuits 21, 22, 23 are supplied to respective windings 11a, 12a, 13a configuring 1st, 2nd and 3rd magnetic flux generating winding pairs through DC amplifiers 31, 32, 33, respectively. Furthermore, windings 11b, 12b, 13b are respectively connected in series with the windings 11a, 12a, 13a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube display for displaying a color image using a cathode ray tube. More specifically, it is intended to always accurately correct the landing of an electron beam in a color cathode ray tube.

[0002]

2. Description of the Related Art In a color cathode ray tube, for example, a three-electron beam selected by a shadow mask or an aperture grill is accurately irradiated (landed) on each phosphor to reproduce a color image. Has become. In contrast, such an electron beam
For example, accidentally irradiating an adjacent phosphor (mislanding)
When it is done, color development of other colors occurs and color purity (purity)
, And a correct color image cannot be reproduced.

Therefore, conventionally, for example, a magnet for correction (purity magnet) is attached to a funnel portion on the back of a color cathode ray tube, and the trajectory of the electron beam is changed by the magnetic field of the magnet, so that the electron beam is applied to each phosphor. Landing correction is performed so as to accurately irradiate the light. However, with such a means, for example, a fixed adjustment is performed at the time of manufacturing, and it is not possible to cope with a so-called temperature drift, geomagnetic drift, or the like.

[0004] That is, depending on the expansion and contraction of a shadow mask, an aperture grill, and the like due to the environmental temperature of the installation place of the receiver (color cathode ray tube display device), and the orientation of the color cathode ray tube when the receiver is installed, the landing is also affected. The amount of change is variable. However, in the above-described correction using the correction magnet, the correction amount is a static correction with a constant amount, and thus cannot be corrected for such a fluctuation due to a temperature drift, a geomagnetic drift, or the like.

On the other hand, there has been proposed a means in which a so-called temperature sensor or terrestrial magnetism sensor is incorporated in a receiver, and a current is supplied to a correction coil or the like, or landing correction is performed using a bimetal or the like. However, in such a means, since the correction is performed by calculating the average value of the deviation of the landing with respect to the temperature and the geomagnetism, a small correction is performed for fear of overcorrection. For this reason, insufficient correction is likely to occur, and it may not be possible to cope with an unexpected change.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and the problem to be solved is that temperature drift, geomagnetic drift, etc., in a conventional correction magnet. May not be able to correct for fluctuations caused by the fluctuations, and it may not be possible to perform sufficient correction even with means using temperature sensors, geomagnetic sensors, etc., and may not be able to respond to unexpected changes etc. It is that there is.

[0007]

Therefore, in the present invention, a winding pair for generating a magnetic flux for landing correction is provided in a funnel portion of a color cathode ray tube, and a plurality of photosensors are arranged around a screen. Landing correction is automatically performed using the output of the photo sensor. According to this, it is possible to correct for fluctuations due to temperature drift, geomagnetic drift, etc. Since the correction is performed by measuring a required value, a sufficient and accurate correction can always be performed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a color cathode ray tube, an upper winding and a lower winding are arranged in a pair in the vertical direction of the color cathode ray tube, and the pair of windings are arranged. Are connected in series or in parallel, and one or more pairs of magnetic flux generating windings are arranged on a funnel portion on the back of the color cathode ray tube, and a signal of a predetermined waveform synchronized with a vertical scanning cycle of a video signal supplied to the color cathode ray tube. , A signal generating means for generating a rectangular waveform signal synchronized with the vertical scanning cycle, and a signal of a predetermined waveform from the signal forming means and a rectangular waveform signal from the signal generating means are added. A driving unit for forming a driving current supplied to the magnetic flux generating winding pair, a plurality of photosensors arranged around a screen of the color cathode ray tube, and a selection unit for selecting an output of the plurality of photosensors; Signal processing means for forming a value necessary for landing correction of a predetermined portion of the screen of the color cathode ray tube based on the selection control information and the output of the selected photosensor by the selection means; A signal having a predetermined waveform is formed by the signal forming means in accordance with a value required for landing correction of a predetermined portion of the screen, and after the signal having the predetermined waveform is formed by the signal forming means, the signal is generated by the signal generating means. The generation of the rectangular waveform signal is stopped.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a color cathode ray tube display device to which the present invention is applied will be described with reference to the drawings. First, FIG. 1 shows the back of a color cathode ray tube to which the present invention is applied. I have.

In FIG. 1, a funnel portion 2 is formed on the back surface of a color cathode ray tube 1 and a neck portion 3 provided with an electron gun is formed at the center thereof. Further, a deflection yoke 4 is provided around the neck 3. The funnel portion 2 has, for example, two windings each generating an equivalent magnetic flux by applying a predetermined current, and these windings are vertically and vertically symmetrically arranged with respect to a center line. The first to third magnetic flux generating winding pairs are provided.

The windings 11a and 11b constituting the first magnetic flux generating winding pair are arranged vertically, for example, with the neck 3 of the funnel 2 interposed therebetween. The windings 12a, 12b and 13a, 13b constituting the second and third magnetic flux generating winding pairs are symmetrically arranged on the left and right sides of the neck portion 3, respectively. These magnetic flux generating winding pairs are provided so as to generate an arbitrary magnetic field in a vertical direction for each pair when an arbitrary current flows through each of the windings 11a to 13b.

Here, a force acts on the electron beam passing through the magnetic field in a direction orthogonal to both the direction of the electron beam and the direction of the magnetic field, and the trajectory of the electron beam is changed in that direction. That is, the electron beam is emitted from the color cathode ray tube 1
When a magnetic field is formed in the vertical direction of the display surface, a force acts in the horizontal direction of the display surface, and the trajectory of the electron beam is changed in the horizontal direction. The amount by which this trajectory is changed is proportional to the strength of the vertical magnetic field formed.

Further, on the back side of the color cathode ray tube 1,
Carbon layer 5 provided by coating on funnel 2
For example, eight photosensors 6a to 6h for detecting light emission of the phosphor on the display surface are provided in a gap between the peripheral surface and the front surface. That is, these photo sensors 6a to 6a
d are arranged at the four corners of the funnel 2 of the color cathode ray tube 1, and the photo sensors 6e to 6h are arranged at the center of the left and right end faces and at the center of the upper and lower end faces, respectively.

These photo sensors 6a to 6h
For example, as shown in FIG. 2, on the front side of the color cathode ray tube 1, four corners around the display surface, the center of the left and right end faces, and the center of the upper and lower end faces may be arranged. Good. Then, depending on the state of light emission of the phosphor detected by these photosensors 6a to 6h, the above-described first to third light sources
A current for performing landing correction is supplied to each of the windings 11a to 13b constituting the magnetic flux generating winding pair.

FIG. 3 shows the photosensor 6 described above.
The configuration of an embodiment of a circuit for flowing a necessary current to each of the windings 11a to 13b in accordance with the light emission state of the phosphor detected in a to 6h is shown. In FIG. 3, the photosensors 6a to 6h detect the light emission amount of the phosphor of the color cathode ray tube 1. The signals from the photo sensors 6a to 6h are amplified by the current-voltage conversion amplifiers 7a to 7h, respectively, and supplied to the signal switching circuit 8.

The signal selected by the signal switching circuit 8 is supplied to a signal processing circuit 9. The signals processed by the signal processing circuit 9 are supplied to correction waveform generation circuits 21, 22, and 23 provided for each of the above-described magnetic flux generation winding pairs. Further, these correction waveform generating circuits 21, 22, 2
3 are supplied with horizontal and vertical synchronizing signals (H, V), respectively, and are changed from the signal processed by the signal processing circuit 9 in synchronization with the vertical scanning cycle, for example, every predetermined number of horizontal scanning cycles. A correction signal is generated.

These correction waveform generation circuits 21, 22, 2
The correction signals generated by the DC amplifiers 3 are
One of the windings 11a, 12a and 13a constituting the first, second and third magnetic flux generating winding pairs through 32 and 33
Supplied to Further, these windings 11a, 12a, 1
The windings 11b, 12b, and 13b are respectively connected in series to 3a. The windings 11a, 11b, 12
The connections of a, 12b and 13a, 13b may each be in parallel.

In such a color cathode ray tube display device, the display surface of the above color cathode ray tube 1 has, for example, red (R) green (G) with a separation band (I) interposed therebetween as shown in FIG. A blue (B) phosphor is provided. Here, as shown in FIG. 4A, for example, if the both ends (broken lines) of the electron beam are irradiated so as to equally lie on the separation bands (I) on both sides, the displacement of the landing position of the electron beam is as follows. The risk of mislanding is minimized.

That is, in this case, even if the landing position of the electron beam is shifted by an amount corresponding to the separation zone (I) on both sides, the amount of light emitted by the irradiation of the electron beam does not change. The maximum permissible amount of the deviation is the state where both ends (broken lines) of the electron beam are equally applied to the separation bands (I) on both sides. Accordingly, an object of the present invention is to perform landing correction so that both ends (broken lines) of the electron beam are equally applied to the separation bands (I) on both sides.

In FIG. 4 described above, for example, when the landing position of the electron beam is moved to the left and right, the ends (broken lines) of the electron beam are separated from the separation band (I) as shown in FIGS. As a result, a non-light emitting portion occurs in the phosphor (R / G / B), and the light emission amount is reduced. However, both ends (broken line) of the electron beam are separated on both sides (I).
, The size of the non-light-emitting portion is equal, and the light-emission amount when moved left and right is equal.

However, as shown in FIG. 4D, for example, when the landing position of the electron beam is shifted, when the landing position of the electron beam is moved to the right (+), the position shown in FIG. As shown, the non-light emitting portion becomes large. When the landing position of the electron beam is moved to the left (-), the non-light-emitting portion becomes smaller as shown in F of FIG. That is, in this case, the amount of light emission when the landing position of the electron beam is moved right and left is different.

That is, even if the landing position of the electron beam is moved right and left as described above, the photo sensor 6a
By performing the landing correction using the windings 11a to 13b so that the light emission amount detected at ６6h does not fluctuate, both ends (broken line) of the electron beam are equally applied to the separation bands (I) on both sides. Will be irradiated. This can minimize the risk of mislanding when the landing position of the electron beam shifts.

Therefore, when such a landing correction is performed in the circuit of FIG. 3, the signal processing circuit 9 firstly outputs a rectangular signal having a vertical period as shown in FIG. A signal is formed such that a waveform is output. If the correction waveform generation circuits 21 to 23 have already formed correction waveforms as shown in FIG. 5B, for example, a correction signal to which these are added as shown in FIG. It is output from the correction waveform generation circuits 21 to 23.

As a result, the windings 11a, 11b, 12a, 12b and 13a constituting the respective magnetic flux generating winding pairs,
13b includes respective correction waveform generation circuits 21, 22,
Currents corresponding to the correction signals generated at 23 flow, and a magnetic field corresponding to these currents is formed in the color cathode ray tube 1 in the vertical direction. The trajectory of the electron beam passing through the magnetic field is changed by the magnetic field generated by these magnetic flux generating winding pairs, and the landing position of the electron beam is changed.

Therefore, as described above, the change in the amount of light emission detected by the photosensors 6a to 6h for each vertical cycle is measured while the landing position of the electron beam is moved right and left. Then, the correction signals generated by the correction waveform generation circuits 21, 22, and 23 are changed so that the change in the light emission amount is reduced and the change is eliminated. As a result, the windings 11a, 11b, 12a, 12b, and 13 are adjusted so that correct landing correction is performed with the rectangular waveform removed.
The current supplied to a and 13b is adjusted.

Further, in the actual processing, one of the photo sensors 6a to 6h is selected by the signal switching circuit 8, and the windings 11a to 11h corresponding to the selected photo sensor are selected.
The current supplied to 13b is adjusted. That is, for example, the current supplied to the windings 13a and 13b is adjusted in a state where the photosensors 6a, 6e and 6b are selected. In the photo sensors 6d, 6g, and 6c, the windings 12a, 12
The current of b is adjusted, and the current of the windings 11a and 11b is adjusted in the photosensors 6h and 6f.

The above-mentioned photo sensors 6a, 6h,
In 6d, the change in the amount of light emission at the upper part of the display surface is measured. In the photo sensors 6e and 6g, the change in the light emission amount at the center of the display surface is measured, and the photo sensors 6b, 6f and 6c are measured.
In, the change in the amount of light emission below the display surface is measured. Therefore, values obtained by performing correction so as to eliminate these changes are stored in the correction waveform generation circuits 21, 22, and 23, and the correction signals corresponding to the respective portions according to the horizontal and vertical synchronization signals (H, V) described above. Is generated.

That is, in order to generate such a correction signal, for example, a microcontroller 41 as shown in FIG. 6 and a nonvolatile one-dimensional memory (storage device) 42 are used as the correction waveform generation circuits 21, 22, and 23. And a circuit including a D / A conversion circuit 43. In FIG. 6, horizontal and vertical synchronization signals (H, V) are supplied to the microcontroller 41, and a predetermined timing signal synchronized with the vertical scanning cycle is formed. This timing signal is supplied to the one-dimensional memory 42.

Here, the one-dimensional memory 42 stores a landing correction amount in consideration of mutual interference between windings for each of the vertical ranges detected by the above-described photosensors 6a to 6h. . Then, the value read from the one-dimensional memory 42 is supplied to a D / A conversion circuit 43 to be converted into an analog signal, and supplied to the corresponding DC amplifiers 31, 32, and 33, respectively. In this way, a predetermined correction signal synchronized with the vertical scanning cycle is formed.

In the above-described configuration, for example, the amount of light emitted by the photo sensor can be detected for each horizontal synchronization signal, and the landing correction can be performed for each horizontal cycle. However, since the change in the correction amount of the landing is not so sharp, sufficient correction can be performed even if the correction is formed by the three portions of the upper portion, the central portion, and the lower portion as described above. In addition, since the frequency of the correction signal is limited to a low band, the response speed of the DC amplifiers 31, 32, and 33 at the subsequent stage can be reduced.

In this manner, the magnetic flux generating winding pairs (windings 11a, 11b, 12a,
In 2b and 13a, 13b), a desired magnetic field is generated in each portion of the display surface, and the trajectory of the electron beam passing through the magnetic field is changed, so that the landing position of the electron beam is corrected. The landing position at the center of the display surface basically matches.
In a device having a small display surface, the photo sensors 6a at four corners are provided.
It is also possible to implement only with 6d.

Further, the above-described signal processing circuit 9 adds the rectangular waveforms of the vertical cycle to perform measurement, and after the landing correction is performed, the addition of the rectangular waveforms of the vertical cycle is stopped, thereby making it necessary. Sometimes, landing correction can be easily performed. This makes it possible to easily perform the landing correction even when the environmental temperature of the installation location of the receiver changes, or when the orientation of the color cathode ray tube at the time of installation changes.

Further, in the above-described apparatus, since the landing correction can be arbitrarily performed, for example, the deflection yoke can be mechanically preset and fixed, and the productivity of the manufacturing line can be improved. In particular, in the case of a flat-type cathode ray tube, the neck of the deflection yoke needs to be erected in order to reduce pincushion distortion. Can be easily performed.

Therefore, in this apparatus, a winding pair for generating magnetic flux for landing correction is provided in the funnel portion of the color cathode ray tube, a plurality of photosensors are arranged around the screen, and the output of these photosensors is used for landing. By automatically performing correction, it is possible to correct for fluctuations due to temperature drift, geomagnetic drift, etc., and at the same time, the value required for landing correction is measured and corrected. It can be performed.

As a result, it is not possible to correct fluctuations due to temperature drift, geomagnetic drift, and the like by the conventional correction using the magnet for correction, and sufficient correction can be performed by means using a temperature sensor, a geomagnetic sensor, or the like. However, according to the present invention, these problems can be easily solved.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0037]

According to the first aspect of the present invention, a winding pair for generating magnetic flux for landing correction is provided in the funnel portion of the color cathode ray tube, and a plurality of photo sensors are arranged around the screen. By automatically performing landing correction using the output of the sensor, it is possible to correct for fluctuations due to temperature drift, geomagnetic drift, etc., and to perform correction by measuring the value required for landing correction. , It is possible to always perform sufficient and accurate correction.

According to the second aspect of the present invention, the signal processing means detects the output of the selected photosensor in synchronization with the rectangular waveform signal of the signal generating means, and outputs the high-potential rectangular waveform signal. The digital value required for landing correction of the portion of the screen corresponding to the selected photosensor is calculated according to the difference between the output of the photosensor at the time and the photosensor output at the time of the low potential. The stored digital values are stored in storage means corresponding to the portion of the screen, and the stored digital values are read out according to the synchronizing signal of the video signal supplied to the color cathode ray tube. By converting and extracting, necessary landing correction can be performed with a simple configuration.

According to the third aspect of the present invention, the eight photosensors are arranged at four corners of the screen of the color cathode ray tube, at the center of the left and right end faces, and at the center of the upper and lower end faces. Accordingly, it is possible to easily set the correction amount necessary for performing the landing correction of the entire display surface.

According to the fourth aspect of the present invention, the magnetic flux generating winding pair is composed of three pairs, and the first magnetic flux generating winding pair is provided with an electron gun in a funnel portion on the back surface of the color cathode ray tube. The second and third pairs of magnetic flux generating coils are arranged vertically with respect to the neck portion to be formed, and are arranged symmetrically with respect to the neck portion, so that the respective portions of the display surface of the color cathode ray tube are good. This makes it possible to perform an accurate landing correction.

As a result, it is not possible to correct fluctuations due to temperature drift, geomagnetic drift, and the like by the conventional correction using the magnet for correction, and sufficient correction can be performed by means using a temperature sensor, a geomagnetic sensor, or the like. However, according to the present invention, these problems can be easily solved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a main part of an embodiment of a color cathode ray tube display device to which the present invention is applied.

FIG. 2 is a configuration diagram showing a main part of another embodiment of a color cathode ray tube display device to which the present invention is applied.

FIG. 3 is a block diagram showing an embodiment of a circuit configuration of a color cathode ray tube display device to which the present invention is applied.

FIG. 4 is a diagram for explaining the present invention.

FIG. 5 is a diagram for explaining the present invention.

FIG. 6 is a block diagram showing an embodiment of a main part of a circuit configuration of a color cathode ray tube display device to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Color cathode ray tube, 2 ... Funnel part, 3 ... Neck part, 4 ... Deflection yoke, 5 ... Carbon layer, 6a-6h ... Photosensor, 7a-7h ... Current-voltage conversion amplifier, 8
... Signal switching circuit, 9 ... Signal processing circuit, 11a, 11
b: windings constituting a first magnetic flux generating winding pair, 12a,
12b: a winding constituting a second magnetic flux generating winding pair, 13
a, 13b... windings forming a third magnetic flux generating winding pair,
21, 22, 23 ... correction waveform generation circuit, 31, 32, 3
3: DC amplifier, 41: Microcontroller, 42:
Non-volatile one-dimensional memory, 43 ... D / A conversion circuit

Claims (4)

[Claims] 1. A color cathode ray tube, and an upper winding and a lower winding are arranged in a pair in the vertical direction of the color cathode ray tube, and the paired windings are connected in series or in parallel. A pair of magnetic flux generating coils arranged in a funnel portion on the back surface of the color cathode ray tube, and a signal forming means for forming a signal having a predetermined waveform synchronized with a vertical scanning cycle of a video signal supplied to the color cathode ray tube Signal generating means for generating a rectangular waveform signal synchronized with the vertical scanning cycle; adding a predetermined waveform signal from the signal forming means and a rectangular waveform signal from the signal generating means to generate the magnetic flux A driving means for forming a driving current supplied to the pair of windings; a plurality of photosensors arranged around a screen of the color cathode ray tube; a selecting means for selecting outputs of the plurality of photosensors; Signal processing means for forming a value necessary for landing correction of a predetermined portion of the screen of the color cathode ray tube according to the selection control information and the selected output of the photosensor by means, A signal having a predetermined waveform is formed by the signal forming means in accordance with a value necessary for landing correction of a predetermined portion of the screen, and after the signal having a predetermined waveform is formed by the signal forming means, A color cathode ray tube display device, wherein generation of a rectangular waveform signal by the signal generation means is stopped. 2. The signal processing means detects an output of the selected photosensor in synchronization with a rectangular waveform signal of the signal generating means, and detects when the rectangular waveform signal has a high potential and when the rectangular waveform signal has a low potential. The digital value required for landing correction of the portion of the screen corresponding to the selected photosensor is calculated according to the difference between the outputs of the photosensor at the time, and the signal forming unit calculates the digital value required by the signal processing unit. The stored digital value is stored in storage means corresponding to the portion of the screen, and the stored digital value is read in accordance with a synchronization signal of a video signal supplied to the color cathode ray tube. 2. The color cathode ray tube display device according to claim 1, wherein the color cathode ray tube display is taken out by performing / A conversion. 3. The color cathode ray tube according to claim 3, wherein the photosensors are composed of eight photosensors, and are arranged at four corners of the screen of the color cathode ray tube, a central part of left and right end faces, and a central part of upper and lower end faces. Item 2. A color cathode ray tube display according to item 1. 4. The magnetic flux generating winding pair is composed of three pairs, and the first magnetic flux generating winding pair is disposed on a back side of the color cathode ray tube with respect to a neck portion provided with an electron gun of a funnel portion. 2. The color cathode ray tube display device according to claim 1, wherein the second and third pairs of magnetic flux generating windings are arranged vertically and symmetrically with respect to the neck portion. 3.