JP2005020149A - Landing correction apparatus and display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a landing correction apparatus capable of eliminating color unevenness by a simple method even in the case of a television set used at a high land and to provide a display apparatus. <P>SOLUTION: The landing correction apparatus includes: a 2-pole electromagnetic coil perpendicularly fitted to the neck part of a cathode ray tube; a timing generating means for generating the timing signal synchronously with a horizontal / vertical synchronizing signal for deflecting the electron beam; a storage means for storing the correction data corresponding to an atmospheric pressure and a position of a screen; and a current conversion means for reading the correction data corresponding to the atmospheric pressure synchronously with the timing signal from the timing generating means and generating a correction waveform current supplied to the 2-pole electromagnetic coil on the basis of the read correction data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a landing correction device and a display device, and more particularly, to a landing correction device and a display device that can cope with a change in atmospheric pressure.
[0002]
[Prior art]
In general, there is a magnetic field due to geomagnetism on the earth, and its direction and strength vary from region to region. Therefore, when a display device using a cathode ray tube (CRT) is placed in such a magnetic field, the electron beam trajectory is bent by the influence of the magnetic field, and so-called mislanding reduces the color purity. It will cause problems such as.
In particular, in a high-definition cathode ray tube with a fine phosphor pitch, the same mislanding amount has a large effect on color purity, and the adverse effect of geomagnetism appears greatly.
[0003]
Therefore, landing correction for correcting the scanning trajectory of the electron beam in the cathode ray tube has been conventionally performed. As a method for performing this landing correction, a landing correction coil is attached to the funnel corner portion of the cathode ray tube, and a current is supplied to each coil. It is well known that the color unevenness is corrected by controlling the supply of the color and generating an electromagnetic force for landing correction.
[0004]
FIG. 5 shows an example of a cathode ray tube to which the landing adjusting device is applied.
The cathode ray tube 111 main body includes a face panel portion 112 having a square front shape, a funnel portion 113 joined to the rear of the face panel portion 112, and an electron gun 115 joined to the rear portion of the funnel portion 113. Part 114.
[0005]
First to fourth landing correction coils 116, 117, 118, and 119 are provided at the four corners on the back side of the face panel unit 112 in the funnel unit 113.
A fifth landin correction coil 120 is provided around the face panel unit 112.
[0006]
Further, a deflection yoke 121 is provided at the neck portion 114. The deflection yoke 121 includes a vertical deflection coil and a horizontal deflection coil (not shown).
Various correction magnets 122 such as a purity magnet (color-blunting magnet) are attached to the outer periphery of the electron gun 115 in the neck portion 114.
[0007]
FIG. 6 is a configuration diagram of landing pattern adjustment. Under the control of the microcomputer 131, the drive circuits drive the first to fifth landing correction coils 116, 117, 118, 119, and 120, respectively.
In the microcomputer 131, a standard adjustment value for correcting the landing pattern at the time of manufacture and an adjustment value for performing the landing correction for the influence of the geomagnetism adjusted by a serviceman or the like at the time of installation of the display device or the like are set. Individual adjustment means are connected.
[0008]
The microcomputer 131 is connected to a memory 132 for storing an adjustment value to be passed through each drive circuit for the landing correction coil set by the individual adjustment means 133.
For example, the adjustment value set by the individual adjustment means 133 for correcting the landing pattern at the time of manufacture is stored in the memory 132.
[0009]
The correction of the landing pattern at the time of manufacturing will be described. FIGS. 7 to 9 show the cause of the variation in landing, and FIG. 7 shows the state where the entire screen is shifted to the right side. Actually, the shaft end shifted to the right side is shown, and the dotted line shows the position of the shaft end after correction. In this case, the current in the same direction is passed through the first to fourth landing correction coils 116, 117, 118, and 119, so that the entire screen can be moved leftward or rightward for correction.
[0010]
FIG. 8 is a view showing a state where the shaft end of the corner is twisted. Actually, the state is shown in which the corner shaft ends are twisted clockwise or counterclockwise.
In this case, the currents flowing through the first landing correction coil 116 and the third landing correction coil 118 and the currents flowing through the second landing correction coil 117 and the fourth landing correction coil 119 are caused to flow in opposite directions. Thus, the corner twist can be eliminated and corrected.
[0011]
FIG. 9 is a diagram illustrating the correction of the center twist. The solid line indicates a state where the center shaft end is twisted clockwise or counterclockwise, and the dotted line indicates a state after the center shaft end is corrected. Indicates the state. In this case, the twist of the center can be eliminated and corrected by adjusting the direction of the current flowing through the fifth landing correction coil 120.
[0012]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-10303 (pages 3-4)
[0013]
[Problems to be solved by the invention]
However, in the landing correction apparatus having the structure in which the coil is attached to the funnel corner portion described in the prior art, the change in the trajectory of the electron beam is only at the corner portion or the X-axis end of the cathode ray tube 111 as shown in FIG. There is a problem that the color unevenness generated in the X-axis middle part of the cathode ray tube 111 cannot be corrected.
This is because the cathode ray tube 111 itself expands due to the difference between the internal pressure and the external pressure of the cathode ray tube 111 in a low pressure environment, thereby correcting the trajectory of the electron beam at the X-axis intermediate portion of the cathode ray tube 111. This is because uneven color occurs.
[0014]
Therefore, when the cathode ray tube itself expands due to a change in atmospheric pressure, there is a problem to be solved by correcting the color unevenness generated in the X-axis intermediate portion of the cathode ray tube based on the change in the trajectory of the electron beam.
[0015]
[Means for Solving the Problems]
In order to solve the above problems, a landing correction apparatus and a display apparatus according to the present invention are configured as follows.
[0016]
(1) The landing correction device corresponds to the atmospheric pressure, a bipolar electromagnetic coil mounted perpendicularly to the neck portion of the cathode ray tube, a timing generating means for generating a timing signal synchronized with a horizontal / vertical synchronizing signal for deflecting an electron beam, and And storage means for storing correction data corresponding to the screen position, and correction data corresponding to the atmospheric pressure is read from the storage means in synchronization with a timing signal from the timing generation means, and based on the read correction data Current converting means for generating a correction waveform current to be supplied to the two-pole electromagnetic coil.
[0017]
(2) The display device includes a cathode ray tube and a landing device that corrects the landing of the cathode ray tube, and the landing correction device is a bipolar electromagnetic that is vertically attached to a neck portion of the cathode ray tube. A coil, timing generating means for generating a timing signal synchronized with a horizontal / vertical synchronizing signal for deflecting an electron beam, storage means for storing correction data corresponding to atmospheric pressure and corresponding to a screen position, and the timing generating means Current conversion means for reading correction data corresponding to the atmospheric pressure in synchronization with the timing signal from the storage means and generating a correction waveform current to be supplied to the two-pole electromagnetic coil based on the read correction data. That is.
[0018]
As described above, the correction data corresponding to the atmospheric pressure is read from the storage means, and the correction waveform current based on the correction data is supplied to the two-pole electromagnetic coil, so that the difference between the internal atmospheric pressure and the external atmospheric pressure of the cathode ray tube is obtained. It is possible to correct color unevenness in the intermediate portion of the X axis that occurs when the cathode ray tube itself expands.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of a landing correction apparatus and a display apparatus according to the present invention will be described with reference to the drawings.
[0020]
As shown in FIG. 1, the display device 10 having a built-in landing correction device includes a cathode ray tube 11 and a landing correction device 12 that corrects the landing of the cathode ray tube 11.
The cathode ray tube 11 includes a face panel portion 12 having a square front shape, a funnel portion 13 joined to the rear of the face panel portion 12, and a neck portion incorporating an electron gun 15 joined to the rear portion of the funnel portion 13. 14.
[0021]
The funnel part 13 is provided with first to fourth landing correction coils (not shown) at the four corners on the back side of the face panel part 12.
A fifth landin correction coil (not shown) is provided around the face panel unit 12.
[0022]
Further, a deflection yoke 21 is provided on the neck portion 14. The deflection yoke 21 includes a vertical deflection coil and a horizontal deflection coil (not shown).
The neck portion 14 has a configuration in which a two-pole electromagnetic coil 23 is attached so as to be further perpendicular.
[0023]
As shown in FIGS. 1 and 2, the landing correction device 12 is synchronized with a bipolar electromagnetic coil 23 vertically attached to the neck portion 14 of the cathode ray tube 11 and horizontal / vertical synchronization signals 24 and 25 for deflecting an electron beam. Timing generating means 26 for generating the timing signal, storage means 27 for storing correction data corresponding to the atmospheric pressure and corresponding to the screen position, and correction data corresponding to the atmospheric pressure in synchronization with the timing signal from the timing generating means 26 Is converted from the storage means 27, and a current conversion means 28 for generating a correction waveform current to be supplied to the two-pole electromagnetic coil 23 based on the read correction data is provided.
[0024]
The two-pole electromagnetic coil 23 is disposed at the vertical position of the neck portion 14 of the cathode ray tube 11. The two-pole electromagnetic coil 23 disposed at the vertical position is connected in parallel or in series and connected to the current conversion means 28. .
In this embodiment, the two-pole electromagnetic coil 23 is a copper wire wound by several tens of turns. If the amount of movement of the electron beam is small, a coil with a core may be used. Further, in order to fix the position of the two-pole electromagnetic coil 23, a structure in which a coil is wound around a bobbin or a structure in which the two-pole electromagnetic coil 23 itself is fixed to the neck portion 14 with a tape or the like may be used.
[0025]
The storage means 27 is a so-called memory, and for example, divides the screen into 11 × 11 horizontally and stores correction data having an amplitude level corresponding to the amount of electron beam movement required at each position. .
The quantitative switching of the correction data stored in the storage means 27 is performed by an unillustrated barometric sensor, user menu, switch, etc., and the data to be transferred to the memory is linked to output to the bipolar electromagnetic coil 23. Vary the amplitude. This amount of output amplitude can also be varied by the power amplifier of the current conversion means 28.
The current conversion means 28 synchronizes the reading from the storage means 27 with the horizontal synchronization signal and the vertical synchronization signal, converts it into an analog signal by the D / A conversion section, connects it to a broadband power amplifier, and uses a bipolar electromagnetic wave as a correction waveform current. The coil 23 is supplied.
[0026]
Here, the cathode ray tube 11 built in the display device 10 generates color unevenness (mislanding) in a place where the atmospheric pressure is low. The cause of the color unevenness is that the cathode ray tube 11 itself expands due to the difference between the atmospheric pressure inside the cathode ray tube 11 and the external pressure.
[0027]
When there is a difference between the atmospheric pressure in the cathode ray tube 11 and the reduced external atmospheric pressure, the electron beam from the electron gun 15 passes through the color selection mechanism inside the panel of the cathode ray tube 11 and reaches the phosphor screen of the face panel unit 12. However, due to the relationship between the beam incident angle and the expansion coefficient at this time, color unevenness occurs in a circular shape at the left and right central portions on the X axis of the cathode ray tube 11 as shown in FIG. When the external air pressure is 1013 hpa and the screen is a green monochromatic screen, when the external air pressure decreases, a red striped pattern is formed in the left central portion and a blue striped pattern is formed in the right central portion.
In the present invention, in order to correct this color unevenness, as shown in FIG. 1, a two-pole electromagnetic coil 23 is attached to the neck portion 14 of the cathode ray tube 11 in a vertical direction, and the two-pole electromagnetic coil 23 is attached. The problem is solved by supplying a correction waveform current based on the correction data from the storage means 27.
[0028]
Now, as shown in FIG. 4, the signal of the correction waveform current based on the correction data read from the storage means 27 is synchronized with the vertical synchronization signal of the sine wave signal synchronized with the horizontal synchronization signal output from the beam deflection circuit of the television. It is the waveform modulated by the parabolic wave signal made to do. When the electron beam passing through the neck portion 14 of the cathode ray tube 11 is deflected by the magnetic field generated by supplying the signal of the corrected waveform current to the bipolar electromagnetic coil 23, the electron beam can be corrected to the normal position on the phosphor screen. Color unevenness can be corrected.
[0029]
Thus, the correction waveform current signal accumulated in the storage means 27 has a waveform obtained by modulating a sine wave signal synchronized with the horizontal synchronizing signal with a parabolic wave signal synchronized with the vertical synchronizing signal.
[0030]
The correction waveform current signal will be described in more detail. As shown in FIG. 4, the signal modulated by the parabolic wave signal synchronized with the vertical synchronization signal and synchronized with the horizontal synchronization signal among the signals synchronized with the vertical synchronization signal. The first half of the rising edge of the horizontal synchronization signal is applied to the two-pole electromagnetic coil 23 on the left side of the screen, and the second half is on the right side of the screen. Applied to the two-pole electromagnetic coil 23.
[0031]
This is because, as shown in FIG. 3, when the external air pressure is lowered, a positive chevron-shaped signal is applied to the two-pole signal with respect to the uneven color pattern that is a substantially red striped pattern generated on the left side of the screen. By supplying the electromagnetic coil 23, the uneven color pattern can be canceled out. In addition, a negative chevron-shaped signal is applied to the two-pole electromagnetic coil 23 for a color uneven pattern that is a blue stripe that is opposite to the color uneven pattern generated on the left side of the screen. By supplying, you can cancel each other.
Eventually, by supplying a signal that cancels out the uneven color pattern to the two-pole electromagnetic coil 23 with respect to the opposite color uneven pattern generated on the left and right sides of the screen, the cathode ray tube 11 is at a place where the atmospheric pressure at a high place is low. Therefore, the uneven color pattern due to the expansion of the cathode ray tube 11 due to the difference between the internal pressure and the external pressure of the cathode ray tube 11 can be canceled.
In this way, for example, when the display device (television set) 10 is used in an area with an altitude of about 1500 m or more, color unevenness occurring in the left and right intermediate portions of the screen due to the difference between the atmospheric pressure and the pressure inside the cathode ray tube 11 is corrected. By supplying the waveform current to the two-pole electromagnetic coil 23, the color unevenness can be eliminated.
[0032]
Conventionally, a display device (television set) adjusted exclusively for high altitudes is required, but if this landing correction device is used, fine adjustments according to altitude are possible and color unevenness can be completely eliminated. it can.
[0033]
【The invention's effect】
As described above, the landing correction device and the display device according to the present invention have a correction waveform for the two-pole electromagnetic coil even if color unevenness occurs in the left and right intermediate portions of the screen due to the difference between the external pressure and the internal pressure of the cathode ray tube. By supplying the current, there is an effect that the uneven color can be eliminated by correcting the deflection of the electron beam.
[Brief description of the drawings]
FIG. 1 is an explanatory view schematically showing a display device according to the present invention.
FIG. 2 is a block diagram of the landing correction apparatus.
FIG. 3 is an explanatory diagram showing the appearance of the screen when the external air pressure and the external air pressure decrease.
FIG. 4 is a waveform diagram showing how correction waveform data is modulated.
FIG. 5 is a perspective view of a cathode ray tube in the prior art as seen from the back side.
FIG. 6 is a circuit for adjusting a correction coil in the prior art.
FIG. 7 is an explanatory diagram showing a state in which the entire screen in the prior art is shifted to the right side.
FIG. 8 is an explanatory diagram showing a state of corner twist on a screen in the prior art.
FIG. 9 is an explanatory diagram showing a state of center twist on a screen in the prior art.
FIG. 10 is an explanatory diagram showing a screen adjustable range in the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11; Cathode-ray tube, 12; Face panel part, 13; Funnel part, 14; Neck part, 15; Electron gun, 22; Landing correction device, 23: Dipole electromagnetic coil, 24; Vertical synchronizing signal, 25; , 26; timing generation means, 27; storage means, 28; current conversion means.

Claims (2)

A bipolar electromagnetic coil mounted vertically on the neck of the cathode ray tube;
Timing generating means for generating a timing signal synchronized with a horizontal / vertical synchronizing signal for deflecting an electron beam;
Storage means for storing correction data corresponding to the divided screen position corresponding to the atmospheric pressure and dividing the screen by a predetermined area;
Current conversion for reading correction data corresponding to the atmospheric pressure from the storage means in synchronization with a timing signal from the timing generation means, and generating a correction waveform current to be supplied to the two-pole electromagnetic coil based on the read correction data Means,
A landing correction apparatus comprising: A display device comprising a cathode ray tube and a landing device for correcting landing of the cathode ray tube,
The landing correction device includes:
A bipolar electromagnetic coil vertically mounted on the neck of the cathode ray tube;
Timing generating means for generating a timing signal synchronized with a horizontal / vertical synchronizing signal for deflecting an electron beam;
Storage means for storing correction data corresponding to the atmospheric pressure and corresponding to the screen position;
Current conversion for reading correction data corresponding to the atmospheric pressure from the storage means in synchronization with a timing signal from the timing generation means, and generating a correction waveform current to be supplied to the two-pole electromagnetic coil based on the read correction data Means,
A display device comprising:

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