2. Description of the Related Art Generally, cathode ray tubes (CRTs) are designed to reproduce the original picture image on a glass screen through receiving the picture image signals from the external and exciting phosphors coated on the screen with electron beams in accordance with the signals. The CRT includes a phosphor screen on which three different phosphors of the red, green and blue are coated, a shadow mask having a color selection function, an electron gun for emitting electron beams, and a deflection yoke for scanning the electron beams on the phosphor screen.

The shadow mask includes a mask having a plurality of beam-guide apertures in its center, and a skirt bent toward the reverse side to the phosphor screen. The beam-guide apertures land the electron beams deflected by the deflection yoke on the corresponding phosphors of the screen.

Meanwhile, in the course of shadow mask processing, alien substances like oily, floating or metallic materials in the environment (referred to hereinafter more simply as 'dusts') are frequently adhered to the mask, causing the beam- guide apertures formed on the mask to be clogged.

When the beam-guide apertures of the shadow mask is clogged by the dusts, the electron beams are partly or entirely blocked in the beam-guide apertures so that the degree of excitation against the phosphors is deteriorated or serious defects in reproduction of the original picture image is generated.

As described above, the phenomenon that the beam-guide apertures are clogged by the dusts is called a beam-guide aperture clogging defect and considered to be necessarily removed. And a degreasing process and an ultrasonic cleaning process are usually employed to remove the defect.

As described above, although the conventional method of removing the beam-guide aperture clogging defect is performed satisfactorily and the dusts adhered on the shadow mask are entirely removed, the beam-guide apertures may be repeatedly clogged due to dusts newly adhered to the shadow mask during many types of processes before the step of sealing the shadow mask through firmly bonding together the panel and funnel or during the delivering operation of the shadow mask from one process to the following processing step.

Furthermore, it is undesirable to perform the degreasing or ultrasonic cleaning process with respect to the shadow mask whenever each step of processing the shadow mask is completed because it not only decreases the

production effects but also increases the production costs.

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a method and apparatus for removing dusts from the shadow mask which substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a method and apparatus for removing dusts from a shadow mask which can maximize the dust removing effects while its installation as well as its maintenance is easily realized at a low cost.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To accomplish these and other advantages, the dust removing method for the shadow mask includes the steps of feeding a shadow mask to a dust removal position, removing the dusts adhered on the shadow mask by using a dust removal tape for adhering the dusts, and delivering the dust-removed shadow mask to a next process.

In the shadow mask feeding step, the shadow mask is not only fed to

but also immovably fixed on the dust removal position so as to prevent it from being shaken or broken away therefrom.

In the subsequent dust removing step, the dusts adhered on the shadow mask is removed and thus, the beam-guide clogging defect is also removed.

Thereafter, in the shadow mask delivering step, the dust-removed shadow mask is delivered to a next process.

The dust removing apparatus for performing the aforementioned dust removing operation includes a shadow mask feeding and delivering unit for feeding the shadow mask to a dust removal position and delivering the dust- removed shadow mask to a next process, and a dust removing unit for removing the dusts adhered on the shadow mask at the dust removal position by using a dust removal tape for adhering the dusts.

The dust removing apparatus according to the present invention may be an apparatus for removing dusts from the exterior of a shadow mask.

The dust removing apparatus for removing the dusts adhered on the exterior of the shadow mask includes a shadow mask feeding and delivering unit for feeding the shadow mask to a dust removal position and delivering the dust-removed shadow mask to a next process, and an external dust removing unit for removing the dusts adhered on the exterior of the shadow mask at the dust removal position by using a dust removal tape for adhering the dusts.

The dust removing apparatus may be also an apparatus for removing dusts from the interior of a shadow mask.

The dust removing apparatus for removing the dusts adhered on the interior of the shadow mask includes a shadow mask feeding and delivering unit for feeding the shadow mask to a dust removal position and delivering the dust-removed shadow mask to a next process, and an internal dust removing unit for removing the dusts adhered on the interior of the shadow mask at the dust removal position by using a dust removal tape for adhering the dusts.

The dust removing apparatus may be also an apparatus for simultaneously removing dusts from the interior and exterior of a shadow mask.

The dust removing apparatus for simultaneously removing the dusts adhered on the interior and exterior of the shadow mask includes a shadow mask feeding and delivering unit for feeding the shadow mask to a dust removal position and delivering the dust-removed shadow mask to a next process, an internal dust removing unit for removing the dusts adhered on the interior of the shadow mask at the dust removal position by using a first dust removal tape for adhering the dusts, and an external dust removing unit for removing the dusts adhered on the exterior of the shadow mask at the dust removal position by using a second dust removal tape for adhering the dusts.

As described above, in the inventive method and apparatus for removing dusts from the shadow mask, the dusts adhered on the shadow mask are rapidly removed so that the cleanness of the shadow mask can be constantly kept. Furthermore, it is installed at a low cost and narrow space and thus, several devices can be provided to remove the dusts adhered on the shadow mask in the course of the shadow mask processing. In addition, the

beam-guide aperture clogging defect can be removed owing to rapid and effective removal of the dusts from the shadow mask.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate a particular embodiment of the invention and, together with the description, serve to explain the principles of the invention.

In the drawings: Fig. 1 is a front view of a dust removing apparatus for removing dusts from the exterior of a shadow mask according to a first preferred embodiment of the present invention; Fig. 2a is a front view showing the initial state of the dust removing apparatus according to the first preferred embodiment; Fig. 2b is a front view showing the state of the dust removing apparatus in which a dust removal tape is attached on the shadow mask, according to the first preferred embodiment; Fig. 2c is a front view of the dust removing apparatus showing the operation of a pressure cylinder according to the first preferred embodiment; Fig. 3 is a perspective view of a dust removing apparatus for removing

dusts from the interior of a shadow mask according to a second preferred embodiment of the present invention; Fig. 4 is a plan view of the dust removing apparatus according to the second preferred embodiment; Fig. 5a is a front view showing the initial state of the dust removing apparatus according to the second preferred embodiment; Fig. 5b is a fragmentary sectional front view showing the state of the dust removing apparatus in which a pipe is elevated, according to the second preferred embodiment; Fig. 5c is a fragmentary sectional front view showing the state of the dust removing apparatus in which a balloon is blown up and a dust removal tape is attached on the interior of the shadow mask; according to the second preferred embodiment; Fig. 5d is a fragmentary sectional front view showing the state of the dust removing apparatus in which a pipe is lowered, according to the second preferred embodiment; Fig. 6 is a perspective view of a dust removing apparatus for simultaneously removing dusts from the interior and exterior of a shadow mask according to a third preferred embodiment of the present invention; Fig. 7a is a front view showing the initial state of the dust removing apparatus according to the third preferred embodiment; Fig. 7b is a front view showing the state of the dust removing apparatus in which dust removing tapes are attached on the interior and exterior of the

shadow mask, according to the third preferred embodiment; Fig. 7c is a front view showing the state of the dust removing apparatus in which the dust removing tapes are uniformly attached on the interior and exterior of the shadow mask by the operation of an air feeder and a balloon, according to the third preferred embodiment; and Fig. 7d is a front view showing the state of the dust removing apparatus in which the dust removing tapes are detached from the interior and exterior of the shadow mask, according to the third preferred embodiment.

In the following detailed description, only the preferred embodiment of the invention has been shown and described, simply by way of illustration of the best mode contemplated by the inventor(s) of carrying out the invention. As will be realized, the invention is capable of modification in various obvious respects, all without departing from the invention. Accordingly, the drawing and description are to be regarded as illustrative in nature, and not as restrictive.

DETAILED DESCRIPTION OF THE INVENTION Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

The dust removing apparatus for the shadow mask according to the present invention includes a shadow mask feeding and delivering unit for feeding the shadow mask to a dust removal position and delivering the dust-

removed shadow mask to a next process, and a dust removing unit for removing the dusts adhered on the shadow mask at the dust removal position.

Fig. 1 is a front view of a dust removing apparatus for removing dusts from the exterior of a shadow mask according to a first preferred embodiment of the present invention, Fig. 2a is a front view showing the initial state of the dust removing apparatus according to the first preferred embodiment, Fig. 2b is a front view showing the state of the dust removing apparatus in which a dust removal tape is attached on the shadow mask, and Fig. 2c is a front view of the dust removing apparatus showing the operation of a pressure cylinder according to the first preferred embodiment.

The dust removing apparatus for removing dusts from the exterior of the shadow mask according to the first preferred embodiment includes a shadow mask feeding and delivering unit for feeding the shadow mask S to a dust removal position and delivering the dust-removed shadow mask S to a next process, and an external dust removing unit for removing the dusts adhered on the exterior of the shadow mask at the dust removal position.

The shadow mask feeding and delivering unit includes a conveyer C for smoothly guiding the shadow mask S.

The conveyer C is arranged between delivering devices (not shown).

In this preferred embodiment, the conveyer C is a roller conveyer, but a belt conveyer is also applicable.

The external dust removing unit includes a base frame 1 positioned above the roller conveyer C, a dust removal tape 3 having a side applied with

adhesive materials, a tape guide unit for guiding the dust removal tape 3 onto the exterior of the shadow mask S to attach it thereon or detach it therefrom.

The roller conveyer C is provided with a regular position stopper 5 for stopping the shadow mask S on the dust removal position. The regular position stopper 5 is driven by an actuator (not shown).

The roller conveyer C is further provided with an interference prevention stopper 7 for preventing the shadow mask fixed on the dust removal position from interfering with a following shadow mask.

The regular position stopper 5 and the interference prevention stopper 7 are installed on stopper supporting members (not shown) respectively. The stopper supporting members are disposed on both sides of a conveyer frame 9 centering around the dust removal position. The regular position stopper 5 is placed on the stopper supporting member positioned in the progressive direction of the shadow mask while the interference prevention stopper 7 is placed on the other stopper supporting member in the opposite direction thereto.

The dust removal tape 3 has an end wound on a circular winding base (not shown) mounted on a rotary roller 11 which is rotatably fixed on the base frame 1. The dust removal tape 3 also has an opposing end wound on the other winding base (not shown) mounted on a winding roller 13. The winding roller 13 is spaced apart from the rotary roller 11 with a predetermined distance.

The width of the dust removal tape 3 is greater than that of a mask portion of the shadow mask S. The dust removal tape 3 is a polyethylene tape

and has a thickness of 0.05 mm, an adhesive force of 120g/25 mm, a tensional strength of 0.8 kg/1O mm, a tensional rate of 300%, and a transparent color.

The tape guide unit includes two elevators 15 and 17 fixed on the base frame 1. The elevators 15 and 17 includes guide cylinders 15a and 17a for receiving air pressure from the external, and guide pistons 15b and 17b connected to the guide cylinders 15a and 17a respectively to be raised or lowered by the air pressure fed therefrom.

The guide cylinders 15a and 17a are arranged between the rotary roller 11 and the winding roller 13 parallel to each other. The distance between the guide cylinders 15a and 17a should be at least longer than the longitudinal length of the shadow mask S.

In addition, guide rollers 15c and 17c are vertically provided under the guide pistons 15b and 17b respectively to guide the dust removal tape 3.

Guide members 15d and 17d are also provided at the bottom of the guide pistons 15b and 17b to combine the guide pistons 15b and 17b with the guide rollers 15c and 17c such that the guide rollers 15c and 17c can be rotated.

The dust removing tape 3 lengthened between the rotary roller 11 and the winding roller 13 is arranged above the shadow mask S by the guidance of the guide rollers 15c and 17c.

When air pressure is fed to the guide cylinders 15a and 17a so that the guide pistons 15b and 17b descend, the dust removing tape 3 positioned above the shadow mask S makes in contact with the exterior of the shadow mask S.

However, at this time, the dust removal tape 3 does not uniformly contact the

overall surface of the shadow mask S because an air is remained on the contact side or the dust removal tape 3 is unnecessarily lengthened between the guide rollers 15c and 17c. This causes an unsatisfactory dust removal operation with respect to the exterior of the shadow mask S.

Therefore, a pressure contact unit is provided between the guide pistons 15b and 17b to secure the uniform contacting between the dust removal tape 3 and the exterior of the shadow mask S. For that purpose, the pressure contact unit spurts high-pressure air on the contact side between the dust removal tape 3 and the shadow mask S.

The pressure contact unit includes two pressure cylinders 19 for receiving air pressure from the external, pressure pistons 19a connected to the pressure cylinders 19 respectively to be raised and lowered by the air pressure fed therefrom, and an air feeder 1 9b fixed on the bottom of the pressure pistons 19a to spurt the high-pressure air on the dust removal tape 3 contacting the shadow mask S.

Meanwhile, after the dust removing operation, the dust removal tape 3 should be detached from the shadow mask S and wound on the winding roller 13.

For that purpose, a motor 21 is connected to the winding roller 13.

The winding roller 13 is rotated by the motor 21 to wind the dust removal tape 3 thereon. Therefore, the contact side of the dust removing tape 3 with the shadow mask S is continuously replaced by a new one so that deterioration in the dust removal efficiency can be prevented.

As described above, when the dust removal tape 3 is attached on or detached from the shadow mask S by the tape guide unit and the pressure contact unit, the shadow mask S should be fixed on the dust removal position for a complete dust removing operation.

Therefore, a plurality of position fixation stoppers 23 is provided on the conveyer frame 9 of the roller conveyer C. The position fixation stoppers 23 each are driven by an actuator (not shown) and pressurize the skirt of the shadow mask S to immovably fix it.

Furthermore, a plurality of supporting rollers 25 are provided between the rotary roller 11 and the guide roller 15c as well as between the winding roller 13 and the other guide roller 17c. The supporting rollers 25 prevent the dust removing tape 3 from being shaken or attached on other components including the base frame 1.

The operation of the dust removing apparatus will be now described with reference to Figs. 2a - 2c.

When a shadow mask S is fed to the dust removal position by the guidance of the roller conveyer C, the regular position stopper 5 is operated to correctly stop the shadow mask S on the dust removal position.

And the interference prevention stopper 7 is protruded backward the shadow mask S and prevents it from interfering with a following shadow mask S.

As a result, the shadow mask S is not broken away from the dust removal position.

At this time, the position fixation stoppers 23 pressurize the shadow mask S to immovably fix it.

Thereafter, air pressure is fed into the guide cylinders 15a and 17a and hence, the guide pistons 15b and 17b movably connected to the guide cylinders 15a and 17a descend toward the exterior of the shadow mask S.

Then, the guide rollers 15c and 17c connected to the guide pistons 15b and 17b are operated to attach the dust removal tape 3 on the exterior of the shadow mask S. Thereafter, air pressure is fed into the pressure cylinders 19 and hence, the pressure pistons 19a descend toward the shadow mask S.

At this time, the air feeder 1 9b fixed on the bottom of the pressure pistons 1 9a is spaced apart from the dust removal tape 3 contacting the shadow mask S with a predetermined distance.

The air feeder 1 9b spurts high-pressure air on the dust removal tape 3 to uniformly attach the dust removal tape 3 on the exterior of the shadow mask S.

Some seconds later, the air pressure fed into the pressure cylinders 19 releases and therefore, the pressure pistons 19a and the air feeder 19b each successively connected to the pressure cylinders 19 are elevated to thereby return to the initial position.

When the pressure contact unit returns to the initial position, the air pressure of the guide cylinder 17a positioned close to the winding roller 13 first releases so that the guide piston 17b and the guide roller 17c are elevated.

Then, the motor 21 rotates the winding roller 13 with a predetermined angle to detach the dust removal tape 3 from the shadow mask S.

Subsequently, the air pressure of the other guide cylinder 15a positioned close to the rotary roller 11 releases so that the guide piston 15b and the guide roller 15c are elevated to thereby return to the initial position.

As a result, the dust removal tape 3 passing through the dust removing operation is detached from the shadow mask S and wound on the winding roller 13.

As described above, when the dust removal tape is detached from the shadow mask, the pressure pistons 15b and 17b are separately elevated to minimize the possibility that the shadow mask S is broken away from the dust removal position due to the adhesive force operating between the dust removal tape and the shadow mask.

When the dust removing operation is completed and hence, the dust removal tape 3, the tape guide unit and the pressure contact unit return to the initial position, the position fixation stoppers 23 release their pressurization onto the shadow mask S and the regular position stopper and the interference prevention stopper enter into the corresponding stopper supporting member.

Subsequently, the roller conveyer C delivers the dust-removed shadow mask S to the next process and simultaneously feeds a new shadow mask S to the dust removal position.

The dust removing operation can be continuously performed through repeating the aforementioned steps.

Fig. 3 is a perspective view of a dust removing apparatus for removing dusts from the interior of a shadow mask according to a second preferred embodiment of the present invention, Fig. 4 is a plan view of the dust removing apparatus according to the second preferred embodiment, Fig. 5a is a front view showing the initial state of the dust removing apparatus according to the second preferred embodiment, Fig. 5b is a fragmentary sectional front view showing the state of the dust removing apparatus in which a pipe is elevated according to the second preferred embodiment, Fig. Sc is a fragmentary sectional front view showing the state of the dust removing apparatus in which a balloon is blown up and a dust removal tape is attached on the interior of the shadow mask, and Fig. 5d is a fragmentary sectional front view showing the state of the dust removing apparatus in which a pipe is lowered according to the second preferred embodiment.

The dust removing apparatus for removing dusts from the interior of the shadow mask S according to the second preferred embodiment includes a shadow mask feeding and delivering unit for feeding the shadow mask S to a dust removal position and delivering the dust-removed shadow mask S to a next process, and an internal dust removing unit for removing the dusts adhered on the interior of the shadow mask at the dust removal position.

In this second preferred embodiment, the shadow mask feeding and delivering unit is also a roller conveyer C1 as is in the first preferred embodiment, with the exception that the rollers provided on the dust removal position are provided in-between conveyer frames 39 such that a space is

formed therebetween to allow passage of the dust removing unit.

As is in the first preferred embodiment, the roller conveyer C1 is provided with a regular position stopper 35, an interference prevention stopper 37 and position fixation stoppers 53.

The internal dust removing unit includes a dust removal tape 33 and a tape attachment unit for guiding the dust removal tape 33 onto the interior of the shadow mask S to attach it thereon or detach it therefrom. The dust removal tape 33 is a polyethylene tape as is in the first preferred embodiment.

The tape attachment unit includes a balloon 45 positioned under the shadow mask S.

The dust removal tape 33 has an end wound on a circular winding base mounted on a rotary roller 41 which is installed between supporting members 39a on the one side. The dust removal tape 33 also has an opposing end wound on the other winding base mounted on a winding roller 43 which is installed between supporting members 39a on the other side.

The dust removal tape 33 lengthened between the rotary roller 41 and the winding roller 43 is positioned between the shadow mask S and the balloon 45. The side of the dust removal tape 33 applied with adhesive materials faces toward the shadow mask S.

In the meantime, a pipe 47 is connected to the bottom of the balloon 45.

The pipe is to feed air into the balloon 45 to inflate it while the pipe supports the balloon 45.

The balloon 45 inflates to uniformly attach the dust removal tape 33 on the interior of the shadow mask S or deflates to detach it therefrom. The upper portion of the inflated balloon 45 has the same curvature as the interior of the shadow mask S.

The balloon 45 should be elevated toward the interior of the shadow mask S to uniformly attach the dust removal tape 33 thereon. Thus, a lift 49 is connected to the bottom of the pipe 47 to raise or lower the balloon 45 together with the pipe 47.

A hose 49a is connected to one side of the lift 49 to feed high-pressure air thereto. The lift 49 receives high-pressure air from the hose 49a to feed it into the pipe 47 or to elevate the pipe 47.

A motor 51 is connected to the winding roller 43 to rotate it and thereby detach the dust removal tape 33 from the interior of the shadow mask S.

The dust removing operation according to the second preferred embodiment can be described as shown below.

When a shadow mask S is fed to the dust removal position by the guidance of the conveyer frame 39, the regular position stopper 35 is protruded to correctly stop the shadow mask S on the dust removal position and the interference prevention stopper 37 is also protruded to prevent the shadow mask S from interfering with a following shadow mask.

Furthermore, position fixation stoppers 53 provided on the conveyer frame 39 pressurize the shadow mask S to immovably fix it on the dust removal position.

Thereafter, high-pressure air is fed into the lift 49 through the hose 49a to elevate the pipe 47. Therefore, the balloon 45 fixed on the upper portion of the pipe 47 is elevated together to attach the dust removal tape 33 on the interior of the shadow mask S.

Then, the balloon 45 is inflated upon receipt of air from the lift 49 through the pipe 47 to uniformly attach the dust removal tape 33 on the interior of the shadow mask S.

Some seconds later, the air fed into the balloon 45 is discharged through the hose 49a and hence, the balloon 45 is deflated. At this time, the pipe 47 descends to thereby return to the initial state.

However, at that state, the dust removal tape 33 may still be attached on the interior of the shadow mask S due to adhesive force of the contact side.

Thus, the motor 51 rotates the winding roller 43 with a predetermined angle to wind the dust removal tape 33 thereon. As a result, the dust removal tape 33 passing through the dust removing operation is entirely detached from the interior of the shadow mask S.

When the dust removal tape 33 is detached from the interior of the shadow mask S, the regular position stopper 35 and the interference prevention stopper 37 enter into the stopper supporting members 39b respectively and the position fixation stoppers 53 are separated from the shadow mask S.

Subsequently, the roller conveyer C1 delivers the dust-removed shadow mask S to the next process, and feeds a new shadow mask S to the dust removal position so that the dust removing operation described above can

be continuously performed.

Fig. 6 is a perspective view showing a dust removal apparatus for simultaneously removing dusts from the interior and exterior of a shadow mask according to a third preferred embodiment of the present invention, Fig. 7a is a front view showing the initial state of the dust removing apparatus according to the third preferred embodiment, Fig. 7b is a front view showing the state of the dust removing apparatus in which dust removal tapes are attached on the interior and exterior of the shadow mask according to the third preferred embodiment, Fig. 7c is a front view showing the state of the dust removing apparatus in which the dust removal tapes are uniformly attached on the interior and exterior of the shadow mask by the operation of an air feeder and a balloon according to the third preferred embodiment, and Fig. 7d is a front view showing the state of the dust removing apparatus in which the dust removal tapes are detached from the interior and exterior of the shadow mask according to the third preferred embodiment.

The dust removing apparatus for simultaneously removing dusts from the interior and exterior of the shadow mask according to the third preferred embodiment includes a shadow mask feeding and delivering unit for feeding the shadow mask S to a dust removal position and delivering the dust-removed shadow mask S to a next process, an external dust removing unit for removing the dusts adhered to the exterior of the shadow mask at the dust removal position, and an internal dust removing unit for removing the dusts adhered to the interior of the shadow mask at the dust removal position.

In this preferred embodiment, the shadow mask feeding and delivering unit is also a roller conveyer C2 and provided with a regular position stopper 65, an interference prevention stopper 67 and a plurality of position fixation stoppers 93 as are in the previous preferred embodiments.

The external dust removing unit includes a base frame 61 positioned above the roller conveyer C2, a first dust removal tape 63 having a contact side applied with adhesive materials, a tape guide unit for guiding the first dust removal tape 63 onto the exterior of the shadow mask S to attach it thereon or to detach it therefrom.

The first dust removal tape 63 has an end wound on a circular winding base mounted on a rotary roller 71 which is rotatably fixed on the base frame 61. The first dust removal tape 63 also has an opposing end wound on the other winding base mounted on a winding roller 73. The winding roller 73 is spaced apart from the rotary roller 71 with a predetermined distance.

The first dust removal tape 63 is a polyethylene tape as is in the first preferred embodiment.

The tape guide unit includes two elevators 75 and 77 fixed on the base frame 61. The elevators 75 and 77 include guide cylinders 75a and 77a for receiving air pressure from the external, and guide pistons 75b and 77b connected to the guide cylinders 75a and 77a respectively to be raised or lowered by the air pressure fed therefrom.

The guide cylinders 75a and 77a is arranged between the rotary roller 71 and the winding roller 73 parallel to each other. The distance between the

guide cylinders 75a and 77a should be at least longer than the longitudinal length of the shadow mask S.

In addition, guide rollers 75c and 77c are vertically provided under the guide pistons 75b and 77b respectively to guide the first dust removal tape 63.

Guide members 75d and 77d are also provided at the bottom of the guide pistons 75b and 77b to combine the guide pistons 75b and 77b with the guide rollers 75c and 77c such that the guide rollers 75c and 77c can be rotated.

The first dust removing tape 63 lengthened between the rotary roller 71 and the winding roller 73 is arranged above the shadow mask S by the guidance of the guide rollers 75c and 77c.

When air pressure is fed into the guide cylinders 75a and 77a so that the guide pistons 75b and 77b descend, the first dust removing tape 63 positioned above the shadow mask S makes in contact with the exterior of the shadow mask S. However, at this time, the first dust removal tape 63 does not uniformly contact the overall surface of the shadow mask S because an air is remained on the contact side or the first dust removal tape 63 is unnecessarily lengthened between the guide rollers 75c and 77c. This causes an unsatisfactory dust removal operation with respect to the exterior of the shadow mask S.

Therefore, a pressure contact unit is provided between the guide pistons 75b and 77b to secure the uniform contacting between the first dust removal tape 63 and the exterior of the shadow mask S. For that purpose, the pressure contact unit spurts high-pressure air on the contact side between the

first dust removal tape 63 and the shadow mask S.

The pressure contact unit includes two pressure cylinders 79 for receiving air pressure from the external, pressure pistons 79a movably connected to the pressure cylinders 79 respectively to be raised and lowered by the air pressure fed therefrom, and an air feeder 79b fixed on the bottom of the pressure pistons 79a to spurt high-pressure air on the first dust removal tape 63 contacting the shadow mask S.

Meanwhile, after the dust removing operation, the first dust removal tape 63 should be detached from the shadow mask S and wound on the winding roller 73.

For that purpose, a motor 80 is connected to the winding roller 73.

The winding roller 73 is rotated by the motor 21 to wind the first dust removal tape 63 thereon. Therefore, the contact side of the first dust removal tape 63 is continuously replaced by a new one so that deterioration in the dust removal efficiency can be prevented.

Furthermore, a plurality of supporting rollers 85 are provided between the rotary roller 71 and the guide roller 75c as well as between the winding roller 73 and the other guide roller 77c. The supporting rollers 85 prevent the first dust removing tape 63 from being shaken or attached on other components including the base frame 61.

The internal dust removing unit includes a second dust removal tape 63 and a tape attachment unit for guiding the second dust removal tape 63 onto the interior of the shadow mask S to attach thereon or detach therefrom.

The tape attachment unit includes a balloon 85 positioned under the shadow mask S.

The second dust removal tape 63 has an end wound on a circular winding base mounted on a rotary roller 81 which is installed between supporting members 99 on the one side. The second dust removal tape 63 also has an opposing end wound on the other winding base mounted on a winding roller 83 which is installed between supporting members 99 on the other side.

The second dust removal tape 63 lengthened between the rotary roller 81 and the winding roller 83 is positioned between the shadow mask S and the balloon 85. The contact side of the second dust removal tape 63 applied with adhesive materials faces the shadow mask S.

In the meantime, a pipe 87 is connected to the bottom of the balloon 85.

The pipe is to feed air into the balloon 85 to inflate it while the pipe supports the balloon 85.

The balloon 85 inflate to uniformly attach the second dust removal tape 63 on the interior of the shadow mask S or deflates to detach it therefrom.

The upper portion of the inflated balloon 85 has the same curvature as the interior of the shadow mask S.

The balloon 85 should be elevated toward the interior of the shadow mask S to uniformly attach the second dust removal tape 63 thereon. Thus, a lift 89 is connected to the bottom of the pipe 87 to elevate the balloon 85 together with the pipe 87.

The lift 89 receives high-pressure air from the external to feed it into the pipe 87 or raise the pipe 87.

A motor 90 is connected to the winding roller 83 to rotate it and thereby detach the second dust removal tape 63 from the interior of the shadow mask S.

The dust removing operation according to the third preferred embodiment can be described as shown below.

When a shadow mask S is fed to the dust removal position by the guidance of the conveyer frame 69, the regular position stopper 65 is protruded to correctly stop the shadow mask S on the dust removal position and the interference prevention stopper 67 is also protruded to prevent the shadow mask S from interfering with a following shadow mask.

Furthermore, the position fixation stoppers 93 placed on the conveyer frame 69 pressurize the shadow mask S to immovably fix it on the dust removal position.

Thereafter, air pressure is fed into the guide cylinders 75a and 77a and hence, the guide pistons 75b and 77b movably connected to the guide cylinders 75a and 77a descend toward the exterior of the shadow mask S.

Then, the guide rollers 75c and 77c connected to the guide pistons 75b and 77b are operated to attach the first dust removal tape 63 on the exterior of the shadow mask S. Thereafter, an air pressure is fed into the pressure cylinders 79 and hence, the pressure pistons 79a descend toward the shadow mask S.

At this time, the air feeder 79b fixed on the bottom of the pressure pistons 79a is spaced apart from the first dust removal tape 63 contacting the shadow mask S with a predetermined distance.

The air feeder 79b spurts high-pressure air on the first dust removal tape 63 to uniformly attach it on the exterior of the shadow mask S.

Some seconds later, the air pressure fed into the pressure cylinders 79 releases and therefore, the pressure pistons 79a and the air feeder 79b successively connected to the pressure cylinders 79 are elevated to thereby return to the initial position.

When the pressure contact unit returns to the initial position, the air pressure of the guide cylinder 77a positioned close to the winding roller 73 first releases so that the guide piston 77b and the guide roller 77c are elevated.

Then, the motor 80 rotates the winding roller 73 with a predetermined angle to detach the first dust removal tape 63 from the shadow mask S.

Subsequently, the air pressure of the other guide cylinder 75a positioned close to the rotary roller 71 releases so that the guide piston 75b and the guide roller 75c are elevated to thereby return to the initial position.

As a result, the first dust removal tape 63 passing through the dust removing operation is detached from the shadow mask S and wound on the winding roller 73.

As described above, when the first dust removal tape 63 is detached from the exterior of the shadow mask S, the pressure pistons 75b and 77b are separately elevated to minimize the possibility that the shadow mask S is

broken away from the dust removal position due to the adhesive force operating between the first dust removal tape and the shadow mask.

In the meantime, the dust removing operation with respect to the interior of the shadow mask S is performed simultaneously with the dust removing operation with respect to the exterior of the shadow mask S.

When the shadow mask S is fixed on the dust removal position, high- pressure air is fed into the lift 89 from the external to raise the pipe 87.

Therefore, the balloon 85 fixed on the upper portion of the pipe 87 is elevated together to attach the second dust removal tape 63 on the interior of the shadow mask S.

Then, the balloon 85 is inflated upon receipt of air from the lift 89 through the pipe 87 to uniformly attach the second dust removal tape 63 on the interior of the shadow mask S.

Some seconds later, the air fed into the balloon 85 is discharged through the pipe 87 and hence, the balloon 85 is deflated. At this time, the pipe 87 descends to thereby return to the initial state.

However, at that state, the second dust removal tape 63 may still be attached on the interior of the shadow mask S due to adhesive force of the contact side. Thus, the motor 90 rotates the winding roller 83 with a predetermined angle to wind the second dust removal tape 63 thereon. As a result, the second dust removal tape 63 passing through the dust removing operation is entirely detached from the interior of the shadow mask S.

When the dust removing operation with respect to the interior and exterior of the shadow mask S is completed, the position fixation stoppers 93 are separated from the shadow mask S and the regular position stopper 65 and the interference prevention stopper 67 enter into the stopper supporting members 66 respectively.

Subsequently, the roller conveyer C2 delivers the dust-removed shadow mask S to the next process, and feeds a new shadow mask to the dust removal position so that the dust removing operation described above can be continuously performed.

As described above, in the inventive method and apparatus for removing dusts from the shadow mask, the dusts adhered to the shadow mask are rapidly removed so that cleanness of the shadow mask can be constantly kept. Furthermore, it is installed at a low cost and narrow space and thus, several devices can be simultaneously provided to remove the dusts adhered to the shadow mask in the course of the shadow mask processing. In addition, the beam-guide aperture clogging defect can be removed owing to rapid and effective removal of the dusts from the shadow mask.

It will be apparent to those skilled in the art that various modifications and variations can be made in the dust removing apparatus for the shadow mask of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.