JP3399014B2 - Beam hole adjustment method of color selection electrode for cathode ray tube - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, a color picture tube,
About the beam hole adjustment method of a cathode ray tube for color selection electrode used in a display device or the like.

[0002]

2. Description of the Related Art Conventionally, as a color selection electrode for a color cathode ray tube, a color selection electrode called a so-called aperture grill in which a large number of elongated grid elements are stretched at a predetermined pitch has been used. In such an aperture grill, due to friction or catching between the grid element body and the damper wire for vibration prevention, or pitch moire or partial overlapping of the aperture grille caused by catching or overlapping of the grid element bodies, vertical stripes appear on the screen. Unevenness in brightness and poor color purity (color strike) may occur.

The following phenomenon can be considered as the cause. 1. In the furnace through which the cathode ray tube passes in its manufacturing process, the aperture grill is bent by thermal expansion, and then the etching edge of the aperture grill is caught with the damper wire, or the adjacent grid elements are caught or overlapped. Return to room temperature. 2. When a strong alternating magnetic field is applied by a degaussing coil or the like, the etching edge of the aperture grille is caught by the damper wire or the adjacent grid bodies are caught by the vibration of each grid body.

When such pitch moiré and overlapping of the aperture grilles occur, the landing of the electron beam at the generation site is different from the normal state, and the brightness deterioration is recognized as vertical stripe-like brightness unevenness, or to the extent thereof. When the value is large, vertical stripe-shaped color purity defects (color strikes) occur.

That is, as shown in FIG. 5A, when the aperture grill 40 is in a normal state, the electron beam 41 reaches the phosphor stripe 42 through the aperture grill 40. For example, as shown in FIG. 5B. When the damper wire 43 is caught by the grid element body 40a of the aperture grill 40 (circle in the figure),
The grid element body 40a is displaced, for example, the phosphor stripe 4
The irradiation amount of the electron beam 41 with respect to 2a is reduced, which is recognized as deterioration of the brightness of the phosphor stripe 42a. Also,
As shown in FIG. 5C, adjacent grid elements 40b, 4
When 0c is shifted and overlapped, the electron beam 41 is shielded by the grid elements 40b and 40c in the portion of the figure, and the phosphor stripe 42b does not emit light. The phenomenon that 42c emits light (color strike) occurs.

Therefore, conventionally, when such pitch moiré or overlapping of the aperture grille occurs, a shock is applied to the cathode ray tube by a rubber hammer or the like to cause friction or catch between the aperture grille and the damper wire, or between the grid elements. I was trying to release the catches and overlaps.

[0007]

Such a method is simple and effective when the degree of overlap between the pitch moiré and the aperture grill is low, but when these degrees are high, a very large impact is exerted. Since it is necessary, the impact on the characteristics of the cathode ray tube and the external damage may occur.

The present invention has been made in view of the above points of the prior art, and an object thereof is to remove the distortion and partial overlap of the color selection electrodes without adversely affecting the cathode ray tube. Beam hole adjustment of color selection electrode for cathode ray tube
The purpose is to provide an adjustment method .

[0009]

According to the present invention, a color selection electrode is irradiated with an electron beam so that at least a part of a bright line extending in one direction is generated on a display screen, and a part of the color selection electrode is expanded. It is what makes me. In this case, an input for generating a bright line position setting pulse based on the synchronization signal , generating a bright line pulse based on the bright line position setting pulse, and dividing the bright line pulse into three to generate an electron beam. It can also be a signal. In addition, a bright line position setting pulse is generated based on the composite video signal, a bright line pulse is generated based on the bright line position setting pulse, and the bright line pulse and the synchronization signal are combined and divided into three to generate an electron beam. It can also be an input signal for Furthermore
In addition, by means of varying the width of the bright line position setting pulse,
Adjusting the pulse width of the setting pulse to generate a bright line pulse
The generation timing of the bright line pulse is adjusted by the variable
And adjust the position of the bright line.

[0010]

According to the present invention, the color selection electrode is irradiated with an electron beam so as to generate at least a part of the bright line extending in one direction on the display screen, and is heated to expand a part of the color selection electrode. Let As a result, the tension of the color selection electrode is locally weakened, and the partial deformation or overlap occurring in the color selection electrode is released. In this case, a method of generating a bright line position setting pulse based on the synchronization signal , generating a bright line pulse based on the bright line position setting pulse, and dividing the bright line pulse into three to be used as an input signal for generating an electron beam Alternatively, a bright line position setting pulse is generated based on the composite video signal, a bright line pulse is generated based on the bright line position setting pulse, and the bright line pulse and the synchronizing signal are combined and divided into three to generate an electron beam. By using the method of using the input signal for generating a bright line on the display screen of the display device by using a signal from a signal source such as a computer, the position of the bright line can be adjusted arbitrarily. . In addition, the bright line position setting
The width of the bright line position setting pulse
By adjusting and varying the emission line pulse generation timing.
Adjust the timing of the bright line pulse
By adjusting the position, it is possible to
The bright line can be aligned with the portion where the warp occurs.

[0011]

EXAMPLES Hereinafter, the color selection electrodes for cathode ray tubes according to the present invention will be described.
Examples and reference examples of the beam hole adjusting method will be described with reference to FIGS.

FIG. 1 shows a schematic configuration of an adjusting device 1 for carrying out the first reference example . The adjusting device 1 is incorporated in an inspection device for a cathode ray tube, and generally comprises a high voltage power source 2, an electron gun power source 3, a vertical deflection circuit 4, a horizontal deflection circuit 5 and a direct current source 6.

The high voltage power supply 2 is for supplying an anode voltage to the cathode ray tube 7 and is connected to an anode button (not shown) of the cathode ray tube 7.

The electron gun power source 3 applies various voltages (heater voltage, cathode voltage, G ₁ voltage, screen voltage) to the electron gun (not shown) of the cathode ray tube 7 for focusing the electron beam.
The focus voltage is supplied to the cathode ray tube 7.
Is connected to the stem pin 7b provided on the neck portion 7a.

The vertical deflection circuit 4 is for passing a vertical deflection current through a vertical deflection coil (not shown). Further, the direct current source 6 includes a parabolic wave generator 8 and a sawtooth wave generator 9
And a horizontal deflection coil (not shown) of the cathode ray tube 7 via the changeover switch 10. Here, the parabolic wave generator 8 and the sawtooth wave generator 9 enhance the linearity of the bright line appearing on the display screen by modulating the direct current flowing through the horizontal deflection coil with the parabola wave and the sawtooth wave synchronized with the vertical deflection. It is a thing. Further, the direct current source 6 includes a variable resistor 11 and is configured so that the direct current value and the polarity thereof are changed.

Next, a description will be given of a method of removing a color moisturizing electrode using this adjusting device 1, particularly a pitch moire in the aperture grill and an overlap between grid elements.

First, a known inspection process is performed on the completed cathode ray tube 7. That is, the high voltage power supply 2, the electron gun power supply 3, the vertical and horizontal deflection circuits 4 and 5 are driven, and the cathode ray tube 7 is driven.
Is operated in a normal state and a predetermined inspection is performed. in this case,
If pitch moiré or overlapping of grid elements occurs in the aperture grill of the cathode ray tube 7, vertical stripe-like luminance deterioration occurs, and a black line 12 appears on the display screen 7c as shown in FIG. 1A.
Appears. Therefore, in this example , such a pitch moire is removed by the following method.

First, by switching the changeover switch 10, the connection between the horizontal deflection circuit 5 and the horizontal deflection coil is cut off. As a result, the electron beam emitted from the electron gun is deflected only in the vertical direction (y-axis direction), and as shown in FIG. 1A, the bright line 1 extending in the vertical direction near the center of the display screen 7c.
3 occurs. After that, the direct current source 6 and the horizontal deflection coil are connected, and a direct current is passed through the horizontal deflection coil. As a result, the position of the bright line 13 moves left and right (x-axis direction) on the display screen 7c. In this case, the amount of movement of the bright line 13 is changed by changing the value of the current flowing through the horizontal deflection coil,
Further, the moving direction of the bright line 13 is changed by changing the polarity of the current. Further, by adjusting the resistance value of the variable resistor 11 and changing the value and polarity of the current flowing through the horizontal deflection coil, the bright line 13 is moved to the position where the black line 12 is generated on the display screen 7c. As a result, the electron beam is applied to the pitch moire of the aperture grill and the portion where the grid elements are overlapped. In this case, the current density of the bright line 13 is appropriately adjusted by adjusting the electron gun power supply 3.

The irradiation of the electron beam locally heats the periphery of the portion of the aperture grill where the pitch moiré or the like occurs, and the thermal expansion weakens the tension of the grid element body, so that the pitch moiré or the like is easily generated. To be removed.

On the other hand, in the adjusting device 1 of this reference example ,
By modulating the direct current flowing through the horizontal deflection coil with the parabolic wave and the sawtooth wave in synchronization with the vertical deflection, the bright line 13 having high linearity can be obtained even at the corner portion on the screen.
As a result, the bright line 13 can be more accurately positioned parallel to the tension direction of the aperture grille, and the effect can be enhanced.

In this embodiment , the bright line extending in the vertical direction is generated, but the present invention is not limited to this, and the line may extend in other directions as long as the tension direction of the aperture grill.

Next, a second reference example will be described. Ginseng
The example is to remove the pitch moire of the aperture grill in a display device incorporating a cathode ray tube. FIG. 2A shows a system for carrying out the method of this reference example . As shown in the figure, this system is composed of a well-known general-purpose test signal generator 14 and a display device 15, respectively.

The test signal generator 14 has a function of generating a display pattern signal including a vertical line signal such as a cross hatch. On the other hand, the display device 15 includes a cathode ray tube 7 having an aperture grill as a color selection electrode,
Further, it has a function of moving the display position of the image on the display screen 16. The output terminal (not shown) of the test signal generator 14 and the input terminal (not shown) of the display device 15 are connected.

To remove the pitch moiré or the like of the aperture grill using such a system, first, the test signal generator 14 is operated and the crosshatch pattern 1 is displayed on the display screen 16 of the display device 15 as shown in FIG. 2A.
7 is displayed. In this case, crosshatch pattern 17
Is a white pattern and the back is a black pattern.

Then, by adjusting the horizontal deflection position, the horizontal deflection phase, etc. of the data, the crosshatch pattern 17 displayed on the display screen 16 is moved in the horizontal direction (x-axis direction) to obtain an arbitrary bright line. (For example, the bright line 17a) is superposed on the black line 18 corresponding to the portion where the pitch moire or the like occurs. Thereby, as in the case of the first reference example ,
Since this portion is irradiated with the electron beam and locally heated, the tension is weakened by the thermal expansion, and the pitch moire and the like can be easily removed.

Since the current density of the bright line 17a in this reference example depends on the amplitude of the video signal output of the video circuit of the display device 15, the time required for the expansion of the aperture grill is shorter than that in the device of the first reference example. Although it becomes longer, no special device other than the test signal generator 14 and the display device 15 capable of driving the cathode ray tube 7 is required, and pitch moire and the like are removed while the cathode ray tube 7 is attached to the display device 15. It has the advantage of being able to.

Next, an embodiment of the present invention will be described with reference to FIGS.

FIG. 3 shows a schematic configuration of a system for carrying out the method of this embodiment. As shown in the figure, in this system, for example, a signal generating source 19 such as the above-mentioned test signal generator or computer, and a display device 20 for displaying a signal generated from this signal generating source 19. A bright line signal generating device 21 as described below is connected between the signal generating source 19 and the display device 20.

The bright line signal generator 21 includes a signal source 21.
It has a function of processing a signal output from the display device 20 and displaying it as a bright line 23 on the display screen 22 of the display device 20, and changing a display position and a bright line width of the bright line 23.

FIG. 4A shows a circuit configuration of the bright line signal generator 21. As shown in the figure, the bright line signal generator 21 includes a sync separation circuit 24 for extracting a sync signal from the composite video signal CV, a bright line position adjusting circuit 25 for adjusting the display position of the bright line 23, and a bright line 23. A bright line width adjusting circuit 26 for adjusting the width, an adder 27, a gain adjusting circuit 28, a signal distributor 29, and signal lines 32a and 32b.
Composed of and.

The sync separation circuit 24 is used in the bright line signal generator 2
1 is connected to the input terminal 30 and its output terminal is connected to one terminal 31 a of the changeover switch 31. The other terminal 31b of the changeover switch 31 is connected to a signal line 32 for sending a composite synchronizing signal or a horizontal synchronizing signal. The signal line 32b is for transmitting a vertical synchronizing signal.

The output terminal 31c of the changeover switch 31 is connected to the input terminal of the bright line position adjusting circuit 25. The bright line position adjusting circuit 25 includes a one-shot multivibrator (hereinafter referred to as “one-shot multi”) 33 that outputs a pulse having a fixed time width for each input pulse, and a variable resistor 34. Composed.

The output terminal of the bright line position adjusting circuit 25 is connected to the input terminal of the bright line width adjusting circuit 26. Like the bright line position adjusting circuit 25, the bright line width adjusting circuit 26 includes a one-shot multi 35 and a variable resistor 36.

The output terminal of the bright line width adjusting circuit 26 is the adder 2
7 is connected to one input terminal. The other input terminal of the adder 27 is connected to the above-mentioned signal line 32a via the changeover switch 37.

The output terminal of the adder 27 is a gain adjusting circuit 28.
Connected to the input terminal of. The gain adjustment circuit 28 is composed of a reduction circuit using a variable resistor 38. Then, the output terminal of the gain adjusting circuit 28 sends the video signal to red (R),
It is connected to a signal distributor 29 which distributes signals of respective colors of green (G) and blue (B), and is configured to output the video signals of respective colors from the signal distributor 29.

In the present embodiment, as shown in FIG. 4B, the composite video signal CV of, for example, green (G) output from the signal generation source 19 is input to the sync separation circuit 24 of the bright line signal generation device 21, and the same. The composite synchronizing signal as shown in the figure, particularly the horizontal synchronizing signal S _1, is output, and this horizontal synchronizing signal S ₁ is input to the bright line position adjusting circuit 25. Bright line position adjustment circuit 2
5, the one-shot multi 33 is triggered by the horizontal synchronizing signal S ₁ , and the bright line position setting pulse S ₂ as shown in FIG. 4B is output. Then, the one-shot multi 35 of the bright line width adjusting circuit 26 is triggered by the bright line position setting pulse S ₂ , and the bright line pulse S ₃ as shown in FIG. 4B is output. Furthermore, this bright line pulse S
₃ is superposed on the horizontal synchronizing signal S ₁ input via the signal line 32a and the changeover switch 37 in the adder 27, and is input to the signal distributor 29 as a composite video signal S ₅ as shown in FIG. 4B. This composite video signal S ₅ is divided into 3 by the signal distributor 29, and for example, video signals of respective colors of red (R), green (G) and blue (B) are output.

When the signal generation source 19 capable of independently inputting the synchronizing signal is used, the changeover switch 31 is switched to input the horizontal synchronizing signal S ₁ directly to the bright line position adjusting circuit 25 from the signal line 32a. You can also In this case,
It is not necessary to superimpose the horizontal synchronizing signal S ₁ and the bright line pulse S ₃ again, and the changeover switch 37 is switched.
Then, the video signal S ₄ as shown in FIG. 4B is input to the signal distributor 29, and the video signal S ₄ is divided into three and output.

If the luminance signal generator 21 is used,
A video signal output from a signal source 19 such as a computer is processed to display a display screen 22 of a display device 20.
A bright line 23 extending vertically, that is, in the tension direction of the aperture grille can be displayed. The position of the bright line 23 is adjusted by adjusting the variable resistor 34 of the bright line position adjusting circuit 25 to change the pulse width of the bright line position setting pulse S ₂ and the generation timing of the bright line pulse S ₃ .
As shown in FIG. 3B, the bright line 23 is aligned with the black line 39 generated in the portion where the pitch moiré of the aperture grill is generated. As a result, this portion is irradiated with the electron beam, and the aperture grill is locally thermally expanded, so that the tension is weakened and the pitch moire or the like can be easily removed.

In this embodiment, since the signal output from the signal generator 19 such as a general-purpose signal generator or a computer is used as an input signal, a special device as in the first reference example is not required, and Since the bright line position adjusting circuit 25 is provided, it is not necessary to readjust the display position of the image in the display device 20, and the cathode ray tube 7
There is an advantage that the pitch moire and the like can be removed with the device attached to the display device 20.

By the way, in the case of this embodiment, the above-mentioned second reference
As in the case of the example, since the current density of the bright line 23 depends on the amplitude of the video signal output of the video circuit of the display device 20, the current density is lower than that of the device of the first reference example , and the expansion of the aperture grill is required. The time will increase. However, since the general-purpose signal generator adjusts the video signal amplitude to 0.714V with respect to the termination of 75Ω, this is not necessary in the system of the present embodiment, so the amplitude of the video signal is terminated at 75Ω / 0. The maximum amplitude output of the video signal can be more easily obtained by making it variable instead of fixing it to 714V.

In the above-mentioned first reference example and embodiment , the bright lines are generated all over the display screen, but the present invention is not limited to this.
It is also possible to generate a bright line having a length shorter than the width in the axial direction. However, if the length of the bright line is too short, the aperture grill may be partially overheated and the grid element may be cut. Also, the circuit configuration becomes complicated.

Although the crosshatch pattern is used as the parallel pattern in the second reference example , other patterns may be used.

Further, the direction of the bright line used in each example is not limited to the direction of the y-axis, and various directions can be used as long as they extend in one direction. However, it is most effective to use the one that extends in the tension direction of the aperture grill.

In addition, the present invention can also be applied to a cathode ray tube using a shadow mask having a round or slotted beam transmission hole as a color selection electrode, for example. In the case of such a color selection electrode, partial overlapping or the like is unlikely to occur, but dust or the like may adhere, and the present invention is effective in removing such dust or the like.

[0045]

As described above, in the present invention, the color selection electrode is irradiated with the electron beam so that at least a part of the bright line extending in one direction is generated on the display screen, and a part thereof is expanded. By doing so, it is possible to remove the distortion and partial overlap that have occurred in the color selection electrode without adversely affecting the cathode ray tube (change in characteristics, external damage, etc.). In this case, a method of generating a bright line position setting pulse based on the synchronization signal , generating a bright line pulse based on the bright line position setting pulse, and dividing the bright line pulse into three to be used as an input signal for generating an electron beam Alternatively, a bright line position setting pulse is generated based on the composite video signal, a bright line pulse is generated based on the bright line position setting pulse, and the bright line pulse and the synchronizing signal are combined and divided into three to generate an electron beam. By using the method of using an input signal for removing the cathode ray tube from the display device or the like, and without adjusting the display position in the display device or the like, the distortion or partial overlap that occurs in the color selection electrode. Can be removed . Like this
Thus, according to the present invention, it is possible to finally manufacture a high-quality cathode ray tube in which the color selection electrodes are not distorted and do not overlap.

[Brief description of drawings]

FIG. 1A is an explanatory diagram of a first reference example of a method according to the present invention. B is a schematic configuration diagram of an apparatus for carrying out the same reference example . FIG.

FIG. 2A is an external view of a system for carrying out a second reference example of the method according to the present invention. B is an explanatory diagram of the same reference example .

FIG. 3A is an external view of a system for carrying out an embodiment of the method according to the invention . B is an explanatory diagram of the same embodiment. FIG.

FIG. 4 is a circuit configuration diagram of an A line signal generator. B
7 is a timing chart of signals in the bright line signal generator.

FIG. 5 is an explanatory diagram showing pitch moire or partial overlap in the aperture grill.

[Explanation of symbols]

1 adjustment device 2 high voltage power supply Power supply for 3 electron guns 4 Vertical deflection circuit 5 Horizontal deflection circuit 6 Vertical current source 7 Cathode ray tube 8 parabolic wave generator 9 saw wave generator 12 black lines 13 bright lines

Claims (2)

(57) [Claims] 1. A bright line extending in one direction on a display screen.
Color selection of electron beam so that at least part of
Irradiate the electrodes, expand a part of the color selection electrode, generate a bright line position setting pulse based on the synchronization signal, generate a bright line pulse based on the bright line position setting pulse, and divide the bright line pulse into three. an input signal for generating an electron beam Te, the variable means of the width of the bright line position setting pulse, the bright
Adjust the width of the line position setting pulse, and use the variable means for the generation timing of the bright line pulse to
Adjust the generation timing of the bright line pulse to
A method of adjusting a beam hole of a color selection electrode for a cathode ray tube, characterized by adjusting a position . 2. A bright line extending in one direction on a display screen.
Color selection of electron beam so that at least part of
The electrode is irradiated, a part of the color selection electrode is expanded, a bright line position setting pulse is generated based on the composite video signal, a bright line pulse is generated based on the bright line position setting pulse, and the bright line pulse and a synchronization signal are generated. 3 dispensed as an input signal for generating an electron beam, the varying means of the width of the bright line position setting pulse, the bright as well as complex bets
Adjust the width of the line position setting pulse, and use the variable means for the generation timing of the bright line pulse to
Adjust the generation timing of the bright line pulse to
A method of adjusting a beam hole of a color selection electrode for a cathode ray tube, characterized by adjusting a position .