KR100288033B1 - Method and apparatus of menufacturing color cothode ray tube with deflection yoke and display device, and color cathode ray tube manufactured by method thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing a color brown tube and a display device having a deflection yoke attached to the color brown tube and adjusting image quality, and a device and a color brown tube manufactured by the method. In order to provide a manufacturing method of the ITC and the display device which can be executed with high precision, and the manufacturing device and the CRT manufactured by the method, an electron beam is emitted from an electron gun of a color brown tube with an electron gun and attached to a deflection yoke. Irradiate the fluorescent surface, generate a magnetic field approximately parallel to the display surface near the display surface of the color CRT, change the magnetic field approximately parallel to the display surface, and display the irradiation state on the fluorescent surface of the electron beam according to this change. Measured from the surface side, and transfer of the color-brown tube to the phosphor phase according to the measured result Obtaining the amount of the beam landing misses, and the miss is determined according to the amount of the landing configuration running test or adjustment of the color cathode-ray tube.

This makes it possible to manufacture ITCs and display devices that can carry out high-precision and efficient landing inspections and adjustments on the entire screen or at multiple points by inexpensive devices, and realize good color reproduction in any geomagnetic environment. And the effect of contributing to shortening the overall length of the CRT can be obtained.

Description

TECHNICAL FIELD OF THE INVENTION A manufacturing method of a color brown tube and a display device having a deflection yoke, and a manufacturing device and a color brown tube manufactured by the method. METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a color brown tube (hereinafter referred to as ITC) and a display device manufactured by attaching a deflection yoke to a color brown tube and adjusting image quality, a manufacturing apparatus and a color brown tube manufactured by the method.

As shown in the cross-sectional view of Fig. 9A, the red, green, and blue electron beams emitted from the electron gun 29 are deflected in the middle, and are applied to the fluorescent surface 31 through the holes or slits of the color selection mechanism 30. Each phosphor is irradiated to emit light. FIG. 9B shows the state in which the electron beam 20 passing through the color selection mechanism 30 is irradiated to the phosphor 19 in detail. In general, the irradiated electron beam diameter is designed to be several ten percent larger than the diameter of the phosphor, thereby providing an error margin.

The neck 32 of the color brown tube is provided with a purity magnet 33 and a deflection yoke 34. The purity magnet 33 is composed of two sets of annular magnets. The purity magnet 33 can generate a two-pole static magnetic field that can arbitrarily adjust the size and direction thereof, thereby adjusting the irradiation position of the electron beam to the phosphor. The deflection yoke 34 forms an image by deflecting the electron beam up, down, left and right and regularly scanning the screen. However, the angle of incidence of the electron beam into the color selection mechanism depends on a predetermined angle depending on the position in the front-back direction of the neck attachment. Differently, the color periphery may be degraded at the periphery of the screen.

In the ITC manufacturing process, the electron beam may not be irradiated to the center of the phosphor accurately due to the mounting position of the deflection yoke or the manufacturing error of the parts or assembly of the color brown tube. This misalignment of the center position of the landing is called mis-landing, and the amount thereof is called mis-landing amount. If this amount becomes large, adjacent fluorescent substance is irradiated, and color reproducibility deteriorates remarkably.

Landing is caused by geomagnetism in addition to the above ITC manufacturing process and CRT manufacturing error, so the amount of mislanding should be taken into consideration.

In addition, if the amount of mis-landing in each color is different, the balance of emission luminance is broken and color reproducibility is deteriorated, resulting in deterioration of image quality.

If the mis-landing cannot be adjusted by the adjustment of the purity magnet or by the positioning of the deflection yoke, a magnetic member may be attached to the funnel shape on the back of the color-brown tube to perform local correction. It needs to be adjusted carefully. As mentioned above, the inspection and adjustment of mislanding is a very important process in ITC manufacturing.

Miss landing inspection and adjustment are necessary not only in the ITC manufacturing process but also in the quality inspection and adjustment process of the finished display device. This is because the magnetic field around the CRT varies due to the mounting components and the case of the display driving circuit board, and the landing state may be different from that in the ITC. Miss landing is a major cause of deterioration of color reproducibility and is an important inspection item in quality control of final product.

The measurement of the amount of mis-landing is classified into the local measurement method and the front measurement method according to the measurement number. Moreover, according to the installation place of the beam deflector for a measurement, it is classified into a neck deflection method and a panel deflection method. Whereas the local measurement method measures the landing amount at about 10 mm 2, the front measurement method simultaneously measures the landing amount at any part of the screen. The neck deflection method is to install the beam deflector for measurement between the deflection yoke and the purity magnet. The panel deflection method is to be installed on the front surface of the glass panel which is the display surface of the color brown tube and deflect the beam.

The method of calculating the mis-landing amount deflects the electron beam by the same amount in the up-down or left-right direction, and converts the mis-landing amount by the difference in the luminous intensity of each phosphor at that time.

In addition, as the simplest measurement method, an empirical method is obtained from the edge shape of the light emitting part by visual observation using a microscope of about 80 times.

As the color-brown tube becomes more sharp, the distance between adjacent phosphors becomes smaller and the margin of mis-landing is reduced, so that high precision landing adjustment is required. As described above, when the landing of any place is adjusted, the measurement of landing in the whole screen is important for ensuring quality due to the influence of other places and the change of landing due to the change of geomagnetism caused by the installation location or orientation of the display. It is supposed to be done. The above-mentioned local measurement method requires a time for multi-point measurement of the entire screen, so there is a problem in practical use, and a method capable of measuring multiple points at the same time is required. Constraints are taken and high density measurements are difficult.

On the other hand, the neck deflection method requires a gap S for installing the beam deflector between the deflection yoke 34 and the purity magnet 33, as shown in FIG. 9, and this gap S is used to shorten the overall length of the CRT. It is a restriction. In addition, an error of about 3 to 4% may occur at 15 degrees due to the angle of attachment around the neck axis of the beam deflector, making it difficult to attach the beam deflector. In addition, this method has a back cover in the display device of the finished product, so it is difficult to measure.

In addition, since the mislanding amount is converted from the luminance difference when the same amount is deflected in the opposite direction, in the CRT of the dot-shaped phosphor, when the mislanding amount is large, the luminance difference and the mislanding amount are not proportional to each other, resulting in a large error. have.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and it is possible to easily inspect and adjust landings across the screen and to execute a high precision in a short time, and a manufacturing method of the ITC and the display device and the manufacturing apparatus and the method To provide a CRT.

1 is a block diagram showing a color-brown tube ITC manufacturing apparatus according to an embodiment of the present invention,

2 is an explanatory diagram of the configuration and operation of the beam deflector of the embodiment;

3 is an explanatory diagram of a method for manufacturing an iron core of a beam deflector of the embodiment;

4 is an explanatory diagram of a mislanding amount measuring method of the embodiment;

Fig. 5 is an explanatory diagram of the relationship between the light emission length of the phosphor and the coil conduction current in the mislanding amount measurement of the embodiment;

6 is an explanatory diagram of a mislanding amount measuring method according to a second embodiment of the present invention;

7 is an explanatory diagram of a mislanding amount measurement result display screen according to an embodiment of the present invention;

8 is an explanatory diagram of a method for manufacturing a color brown tube ITC, which is an embodiment of the present invention;

9 is an explanatory view of a cross-sectional view of a color brown tube and electron beam irradiation to a phosphor;

10 is an explanatory diagram showing an allowable amount of mislanding;

The present invention is to fix the color brown tube to the attachment frame, a plurality of predetermined currents are applied to the deflection coil wound on the left and right or top and bottom of the ring-shaped iron core to form a gyros installed on the front of the color brown tube, and to each current value A method of manufacturing an ITC and a display device in which a corresponding luminance is measured by an image pickup device to obtain a miss landing amount from measured values, and to easily inspect or adjust a plurality of points or a landing on a screen in a short time and with high precision.

In addition, the present invention is an image pickup device for measuring the brightness of the color brown tube, a ring-shaped iron core for forming a magnetic path provided on the front surface of the color brown tube which horizontally or vertically deflects the electron beam of the color brown tube, and wound around the left and right or up and down of the iron core A beam deflector comprising a deflection coil, a deflection coil current control device for controlling a current flowing through the deflection coil, a memory storing a relationship between the amount of movement of the electron beam and the current flowing through the deflection coil, or the relationship between luminance information and mislanding amount; An ITC and a display apparatus manufacturing apparatus comprising an arithmetic processing unit which calculates a mislanding amount from the data of this memory and the measured value measured by the imaging device.

Hereinafter, the present invention will be described with reference to the drawings. Fig. 1 shows a landing inspection and adjusting device as one embodiment. The monochromatic signal is input to the color brown tube 1 by the signal generator 2. The image pickup device 3 is provided to face the color brown tube, and images of various parts of the entire screen are picked up. The captured image signal is converted into a digital image signal by the AD converter 4 and stored in the image memory 5. The image data written to the image memory 5 is calculated by the arithmetic processing unit 7 in accordance with arithmetic programs stored in the memory 6 in advance. The calculated result is displayed on the result display apparatus 8 via the arithmetic processing unit 7.

On the other hand, a beam deflector 9 for measurement is installed on the front surface of the color brown tube 1, and in the deflection coil current control devices 10 and 11, the horizontal deflection coils 12 and the vertical deflection coils 13, respectively. A current is supplied to apply a measurement magnetic field to the color-brown tube and to move the landing of the electron beam. 2 shows the beam deflector 9 in detail, in which the horizontal deflection coil 12 is wound on the left and right, and the vertical deflection coil 13 is wound up and down on an annular iron core 14 forming a magnetic path. The current flows through the coil so as to generate magnetic fluxes in opposite rotational directions, left, right, and up and down, and the leakage magnetic fluxes 15 and 16 are generated in an area surrounded by an annular iron core. Denoted at 15 is a horizontal deflection coil as magnetic flux in the vertical direction, and at 16 is generated by a vertical deflection coil as magnetic flux in the horizontal direction.

In the magnetic flux in the direction of the arrow shown, the electron beam is deflected upward by the leakage magnetic flux 15 and upward by the leakage magnetic flux 16, and the electron beam center is moved in the same direction, thereby forcibly causing mis-landing. Hereinafter, the direction of the coil energizing current which produces the magnetic flux of the arrow direction of FIG. 2 is demonstrated as positive.

Next, the iron core 14 is shown in detail in FIG. The iron core is made of silicon steel sheet with high permeability and small residual magnetization. The iron core plate 17 of the rectangular shape with the coupling hole shown in Fig. 3A is alternately stacked alternately, and two holes in the center are fastened by bolts, so that one iron core block 18 is shown in Fig. 3B. ) Is formed. Next, as shown in Fig. 3C, when a plurality of iron core blocks are combined to fasten the coupling holes at both ends by bolts to form an annular shape, an iron core for forming a magnetic path is freely formed.

In this embodiment, the amount of misalignment in the up-down, left-right direction is required for the measurement of the mislanding amount in the color-brown tube of the dot-type phosphor. However, in the case of the stripe-type phosphor, only the amount of the misalignment in the left-right direction is good. good.

Next, the landing inspection and adjustment method will be described. In the method according to this embodiment, the mislanding amount in the horizontal direction and the vertical direction can be measured. However, since the measurement principles are the same, only the mislanding amount measurement in the horizontal direction will be described here. Fig. 4 shows that when a current of -2I (A), -I (A), + I (A) and + 2I (A) flows through the deflection coil current control device to the horizontal deflection coil in the state of green monoplane. Fig. 2 shows the change of the image data at the measurement point and the landing state corresponding thereto. Reference numeral 19 denotes a phosphor, and reference numeral 20 denotes a landing electron beam. P ₁ , P ₂ , P ₃ , and P ₄ represent the luminance of the phosphor as image data for each current value. P ₀ is the luminance at no power. In the absence of mis-landing, the maximum luminous intensity and the electron beam movement amount are proportional to the coil energizing current, so that the mis-landing amount is calculated by obtaining the coil energizing current I _max , which maximizes the luminance. I _max is obtained from a current at which the luminance distribution function 21 approximated by the fourth order polynomial is maximized using five data of P ₀ , P ₁ , P ₂ , P ₃ , and P ₄ .

Next, a method of obtaining the relationship between the electron beam shift amount and the coil energizing current will be described. Figure 5 (a) is a landing state at the time of non-energization of the measurement site, when the coil conduction current is gradually increased, the crescent-shaped light emission defect occurs in the phosphor as shown in Figure 5 (b) to reduce the length of the light emitting portion . The emission length L was measured using a microscope while varying the coil conduction current, and the linear approximation equation (22) was obtained by the least square method by plotting the data as shown in Fig. 5C. The linear coefficient K of the linear approximation equation 22 becomes a proportional coefficient of the proportional expression of the electron beam movement amount and the coil energizing current. By the above, the mislanding amount M is calculated | required from the relational formula whose M = KI _max .

Another embodiment related to the mislanding amount measuring method will be described. In the present embodiment, the luminance difference is used while the above-described method is calculated from the luminance distribution. In the above-described method, two types of currents are flowed, respectively, positive and negative, but in the present embodiment, two types of currents, -I (A) and + I (A), are flowed and luminance P ₂ and P for each current value. ₃ , and the mislanding amount M at the luminance P ₀ at the time of no power is obtained by the relational formula of M = C (P ₂ -P ₃ ) / P ₀ . A method of obtaining the coefficient C is shown in FIG. 6B is a landing state when no electricity is applied, and FIGS. 6A and 6C are landing states when currents of -I (A) and + I (A) flow. When the light emission lengths L ₁ and L ₂ of the phosphor 19 for each current value are measured, the mislanding amount M is determined by the relational expression of M = (L ₁ -L ₂ ) / 2. In this way, the relationship between M and (P ₂ -P ₃ ) / P ₀ can be shown. Similarly, the landing magnet is intentionally changed by adjusting the purity magnet, and the data is shown as shown in Fig. 6D, and the linear approximation equation 23 is obtained by the least square method. The coefficient C obtained by the linear coefficient of the linear approximation equation 23 is obtained. This method has an advantage that the accuracy is insufficient when the amount of mislanding is large, but the measurement time is short when the amount of mislanding is not large.

The result calculated in this way is displayed on the result display apparatus 8 via the arithmetic processing apparatus 7. Fig. 7 shows an embodiment of the display screen of the result display apparatus, in which circle (24) shows a display in which the mislanding adjustment range set for each measurement point corresponds to the measurement location of the CRT, and (25) the measurement. The size and direction of the missed landings are coordinated at the same magnification as the circle 24 with the center of the circle 24 as the origin.

The operator of the landing adjustment can see and adjust the purity of the magnet, adjust the position of the deflection yoke, or attach the magnetic member to the back of the CRT tube so as to enter the adjustment range.

According to this embodiment, the landing state of the entire screen can be inspected and adjusted with high accuracy in a short time. Therefore, it is possible to easily make adjustments with a margin for landing variations caused by geomagnetism, and provide an ITC and display device excellent in color reproducibility. Although at least six of (a1), (a2), (a3), (a4) and (b1) and (b2) on the left and right sides of the adjustment points in FIG. 7 may be adjusted, the color selection mechanism and deflection of the CRT can be adjusted. When the precision matching of a yoke is favorable, the location of (a1), (a2), (a3), and (a4) of a corner may be adjusted.

Fig. 10 shows the allowable amount of mislanding in the horizontal direction, and is defined as the amount until the electron beam 20 irradiated to the green phosphor irradiates a portion of the adjacent blue phosphor. If the adjustment range is a value obtained by subtracting the amount of variation caused by the geomagnetism, for example, the magnetic flux density of the horizontal component of the geomagnetism is 0.01-1. If it is within the geomagnetic range of 5 gauss, no color is irradiated over two color phosphors anywhere in the world, and good color reproducibility is obtained.

In addition, in this embodiment, since there is no need to provide a gap between the deflection yoke and the purity magnet, the length corresponding to S of FIG. 9 becomes unnecessary, which can contribute to shortening of the CRT length.

In addition, the measurement of the landing according to the present invention does not require attaching the beam deflector directly to the CRT, and thus can be performed completely automatically, resulting in good workability.

Although the above embodiment has been described with the CRT, the measurement of the landing according to the present invention does not need to directly attach the beam deflector to the CRT as described above. Therefore, the beam deflector described in the above embodiment is also applied to the display apparatus in which the CRT is assembled. Inspection and adjustment can be carried out in the same procedure as the inspection of the CRT.

In the above embodiment, the red color signal and the blue color signal are input to the color brown tube 1 by the signal generator 2 so that the inspection and adjustment of the landing of each color can be similarly carried out in the same procedure as described above.

Next, an example in which the present invention is applied to an ITC manufacturing line will be described using FIG. 8.

The color brown tube is mounted on a base plate 26 and moves on the conveyor 27.

The base plate 26 equipped with the color brown tube circulating on the conveyor 27 in the direction of the arrow stops at a predetermined position on the conveyor 27, and predetermined work is performed on the color brown tube on the base plate 26. After completion of work, it is returned to the next process.

In the example of the manufacturing line shown in FIG. 8, the color brown tube is attached at the position of S2, and the deflection yoke and the purity magnet are assembled. When a series of work is completed at the positions S3 to S7, the ITC finished product is drawn out at the position S8 and only the base plate is returned to the original position S1. The ITC manufacturing process can be divided into color shift, screen distortion, and landing adjustment in large divisions.However, considering the interference and priority, the ITC on the large screen is executed in the order of screen distortion, color shift, and landing adjustment as in S3 to S5. have. The landing inspection adjusting device according to the present invention is installed in S3, S5, S7, and inspects or adjusts the color brown tube flowing on the conveyor 27. The reference point landing adjustment in S3 is a landing adjustment at the center height of the screen left and right, and is performed by adjusting the position of the deflection yoke and the purity magnet. In S5, the landing inspection or adjustment at multiple points or the front surface including at least four corners of the screen is executed.

The inspection failure that does not satisfy the specification is returned to S2 as it is by the return conveyor 28, and the readjustment is performed by replacing the deflection yoke. The information of the inspection failure is written to the storage device provided in the base plate in each process, read in S6, and sent back to the failure. In S7, the final inspection which changes the magnitude and direction of the magnetic field is carried out. Any inspection failures that do not meet the specifications are returned to S2 and readjustment is performed.

By the above adjustment method, the quantitative landing adjustment can be realized at multiple points including the four corners on the screen or at the entire area, so that the defective rate in the final inspection can be reduced to about 1/10 or less as compared with the conventional measurement of several points.

In the above embodiment, the ITC manufacturing process is divided according to the work contents, but since there is no measuring device that interferes with other inspections such as color shifting on the front surface of the CRT display surface, for example, S4 and S5 of FIG. It is also possible to run from. Furthermore, a batch process is also possible in which all processes are executed at one station.

In addition, in the manufacturing process of the display device which is a finished product, it is also possible to perform a landing test other than the chromaticity test which examines color reproducibility.

As described above, according to the present invention, the amount of mislanding is measured and displayed only by measuring a luminance by flowing a predetermined current to an annular measuring beam deflector provided on the front side of the color-brown tube in the inspection or adjustment of the landing. In addition, it is possible to manufacture an ITC and a display device which can perform landing inspection and adjustment work on the whole area or multiple points of the screen with high precision and low cost by means of an inexpensive device. By adjusting the adjustment range of each measurement point by subtracting the amount of variation caused by the geomagnetism and preventing the beam from being irradiated over the adjacent phosphors, good color reproduction can be realized in any geomagnetism environment.

In addition, since the space for attaching the measurement beam deflector to the CRT is unnecessary, an effect that contributes to shortening the overall length of the CRT can be obtained.

Claims (14)

An electron beam is emitted from the electron gun of the color-brown tube with the electron gun and attached to the deflection yoke, and irradiated to the fluorescent surface of the color-brown tube; A magnetic field having a component parallel to the fluorescent surface in front of the fluorescent surface of the color brown tube is generated by a beam deflector arranged on the front surface of the color brown tube, By changing the magnetic field, the average emission luminance of a predetermined region of the fluorescent surface of the electron beam according to the change is measured on the fluorescent surface side of the color CRT, The amount of mis-landing of the electron beam onto the phosphor of the color-brown tube is determined from the relationship between the magnetic field giving the maximum value of the luminous intensity, the previously-established magnetic field and the amount of mis-landing of the electron beam, A method for producing a color brown tube with a deflection yoke, characterized in that the inspection or adjustment of the color brown tube is carried out in accordance with the obtained mislanding amount. The method of claim 1, A method for manufacturing a color brown tube with a deflection yoke, wherein the amount of mis-landing is obtained and inspection or adjustment of the color brown tube is carried out on at least four corners of the fluorescent surface. As a manufacturing method of a display device having a color brown tube, Irradiating the electron beam emitted from the electron gun of this CRT on the fluorescent surface of the CRT of this display device, A magnetic field having a component parallel to the fluorescent surface on the front surface of the fluorescent surface of the color-brown tube of the display device is generated by a magnetic field generator disposed on the front surface of the display device, By changing this magnetic field, the average light emission luminance of a predetermined region of the fluorescent surface of the electron beam according to this change is measured on the fluorescent surface side of the color CRT, The amount of mis-landing of the electron beam onto the phosphor of the color-brown tube is calculated from the relationship between the magnetic field giving the maximum value of the luminous intensity and the previously-grounded amount of mis-landing of the electron beam. A method of manufacturing a display device, characterized in that for performing inspection or adjustment. The method of claim 3, And obtaining the mislanding amount and inspecting or adjusting the display device for at least four corners of the fluorescent screen. A beam deflecting means having a magnetic field generating coil wound around an iron core formed in an annular shape and installed on the front side of the color brown tube and generating a static magnetic field which is emitted from the electron gun of the color brown tube and deflects the electron beam incident on the fluorescent surface of the color brown tube; Coil current control means for switching and flowing two or more kinds of currents having different directions in the magnetic field generating coil to change the direction and magnitude of the generated magnetic field of the beam deflecting means; Imaging means for measuring the emission luminance of the fluorescent surface of the color brown tube when the electron beam emitted from the electron gun is incident on the fluorescent surface of the color brown tube; Estimate the current value at which the luminous luminance is maximized in the state of changing the current and the luminous luminance, and calculates the relationship between the previously obtained current and the electron beam mislanding amount or the ratio of the luminance difference when the government current is applied and the luminance when no current and the electron beam Processing means for obtaining a mislanding amount of the electron beam incident on the fluorescent surface of the color brown tube in relation to the mislanding amount; And a display means for displaying information on the amount of mis-landing of said electron beam obtained by said processing means. The method of claim 5, The processing means is controlled by the coil current control means and the current flowing in the magnetic field generating coil of the beam deflecting means and the movement amount of the electron beam incident on the fluorescent surface at that time, that is, the proportional coefficient of the mislanding amount or the magnetic field generating coil. And a proportional coefficient of mis-landing amount of the electron beam incident on the fluorescent surface in advance. The method of claim 5, And said display means displays information on the amount of mis-landing of at least four corners of said fluorescent screen. The method of claim 5, In the beam deflection means, a magnetic field generating coil is formed in pairs by winding coils in a shape rotating around the iron core on the left and right or up and down of the iron core formed in an annular shape. CRT manufacturing equipment. A beam deflecting means having a coil wound on an iron core formed in an annular shape and installed on the front side of the color brown tube of the display device and generating a static magnetic field which is emitted from an electron gun of the color brown tube and deflects an electron beam incident on the fluorescent surface of the color brown tube; Coil current control means for switching two or more kinds of currents having different directions to the magnetic field generating coils so as to change the direction and magnitude of the generated magnetic field of the beam deflecting means; Imaging means for measuring the emission luminance of the fluorescent surface of the color brown tube when the electron beam emitted from the electron gun is incident on the fluorescent surface of the color brown tube; Estimate the current value at which the luminous luminance is maximized in the state of changing the current and the luminous luminance, and calculates the relationship between the previously obtained current and the electron beam mislanding amount or the ratio of the luminance difference when the government current is applied and the luminance when no current and the electron beam Processing means for obtaining a mislanding amount of the electron beam incident on the fluorescent surface of the color brown tube in relation to the mislanding amount; And display means for displaying information on the amount of mis-landing of said electron beam obtained by said processing means. The method of claim 19, The processing means is controlled by the coil current control means and the current flowing in the magnetic field generating coil of the beam deflecting means and the movement amount of the electron beam incident on the fluorescent surface at that time, that is, the proportional coefficient of the mislanding amount or the magnetic field generating coil. And a proportional coefficient between the ratio of the luminance difference at the time of application of the current and the luminance at the time of no current to the mislanding amount of the electron beam incident on the fluorescent surface. The method of claim 9, And the display means displays information on the amount of mislanding of at least four corners of the fluorescent screen. The method of claim 9, The beam deflecting means, wherein the magnetic field generating coil is formed in pairs by winding coils around the core in a shape rotating around the core in the right and left or up and down of the core formed in an annular shape. An electron beam is emitted from the electron gun of the color-brown tube with the electron gun and attached to the deflection yoke, and irradiated to the fluorescent surface of the color-brown tube, A magnetic field having a component parallel to the fluorescent surface on the front surface of the fluorescent surface of the color brown tube is generated by a beam deflector disposed on the front surface of the color brown tube, By changing the magnetic field, the average emission luminance of a predetermined region of the fluorescent surface of the electron beam according to the change is measured on the fluorescent surface side of the color CRT, The amount of mis-landing of the electron beam onto the phosphor of the color-brown tube is determined by the relationship between the magnetic field giving the maximum value of the light emission luminance, the previously obtained magnetic field and the amount of mis-landing of the electron beam, And a color-brown tube manufactured by performing inspection or adjustment of the color-brown tube in accordance with the obtained mis-landing amount. The method of claim 13, A color brown tube, characterized in that a purity magnet is provided adjacent to the deflection yoke.