Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
  • G01N21/958—Inspecting transparent materials or objects, e.g. windscreens
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/30—Polarising elements
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
  • G01N2021/9513—Liquid crystal panels

Definitions

• the present invention relates to a polarizing film inspection apparatus and a method thereof, and more particularly, to a polarizing film inspection apparatus and a method, in which a gas pad is employed to a conveyer system to rapidly transfer and inspect the polarizing film while maintaining its flatness when inspecting defects of a polarizing film.
• a polarizing film is used as a part of a liquid crystal display (LCD) panel as adhered to one or both sides of a liquid crystal cell.
• LCD liquid crystal display
• An LCD is a display device developed to substitute a cathode ray tube (CRT) used for TV or computer monitor and is widely used in industry because of their lightweight, compactness, high definition image and low power consumption.
• CTR cathode ray tube
• the polarizing film used for an LCD panel may have different configurations depending on its usage, generally it has a laminate structure in which protective films are attached to both sides of a polarizing film. An adhesive layer is formed on one side of the polarizing film to be attached to an LCD panel.
• the polarizing film should be inspected before being attached to an LCD panel.
• a reflecting method and a transmitting method are known in the art as methods for inspecting a polarizing film.
• the reflecting method light is irradiated to one surface of the polarizing film with an inclination angle and then the reflected light is inspected.
• the transmitting method light is perpendicularly irradiated to one surface of the polarizing film and then the transmitted light is inspected at an opposite side.
• the polarizing film which is flexible, is supplied in a form of a scroll wound onto a roll, and is produced through a predetermined process such as cutting.
• a predetermined process such as cutting.
• central portion of the polarizing film may be bent and front or rear portion may be curled, and the inspection accuracy is therefore greatly degraded.
• edges of the polarizing film are clamped by means of a separate clamping unit for keeping the polarizing film to be flat and then inspection is performed.
• the polarizing film is brought into contact with a conveyor using static electricity to keep flatness thereof.
• the present invention provides a polarizing film inspection apparatus and a method in which a polarizing film can be transferred easily and safely and kept flat using a gas pad that uniformly injects a gas.
• a polarizing film inspection apparatus including: first and second gas alignment units each of which includes a pair of gas pads for injecting gas, the pair of the gas pads being vertically arranged to face each other so that a polarizing film is transferred therebetween; and a film inspection unit configured to inspect the polarizing film while the polarizing film is transferred from the first gas alignment unit to the second gas alignment unit.
• the pair of the gas pads included in each of the first and second gas alignment units may have a plurality of gas injection holes formed in any one surface of the respective gas pads;, and gas supplied from the outside may be uniformly injected through the gas injection holes.
• the pair of gas pads may be arranged so that surfaces of the gas pads through which the gas is injected face each other.
• the pair of gas pads vertically arranged to face each other in each of the first and second gas alignment units move up and down respectively to control a gap therebetween.
• the nearest distance between the pair of gas pads vertically arranged to face each other in each of the first and second gas alignment units may equal to a thickness of the polarizing film.
• the first and second gas alignment units may travel in a transfer direction of the polarizing film or in the opposite direction thereto to control a gap therebetween.
• the pair of gas pads vertically arranged to face each other in each of the first and second gas alignment units may travel together.
• the apparatus may further include: a first transfer unit disposed adjacent to the first gas alignment unit to insert the polarizing film into the first gas alignment unit; and a second transfer unit disposed adjacent to the second gas alignment unit to receive a polarizing film discharged from the second gas alignment unit.
• the apparatus may further include a first sensor for detecting a position of the polarizing film inserted into the first gas alignment unit; and a second sensor for detecting a position of the polarizing film transferred from the first gas alignment unit to the second gas alignment units.
• the film inspection unit may include: at least one illuminator arranged adjacent to a position between the first and second gas alignment units for irradiating light with an inclined incident angle to one or both of upper and lower surfaces of the polarizing film being transferred; and at least one camera for detecting light reflected by the polarizing film after being irradiated from the illuminator.
• a polarizing film inspection apparatus including: upper and lower insertion gas pads vertically arranged to face each other, the upper and lower insertion gas pads being moving up and down, and traveling forward and backward; upper and lower discharge gas pads which are spaced apart from the upper and lower insertion gas pads in a horizontal direction, and vertically arranged to face each other, the upper and lower discharge gas moving up and down, and traveling forward and backward; and a film inspection unit configured to inspect a polarizing film being transferred from the upper and lower insertion gas pads to the upper and lower discharge gas pads.
• a guide bar may be installed in a vertical direction at each side of the upper and lower insertion gas pads and the upper and lower discharge gas pads; a guide bracket may be installed at each side of the upper and lower insertion gas pads and the upper and lower discharge gas pads so that each guide bracket is guided by the guide bar in order to guide up/down movement of each of the gas pads; and a lifting link bar may be installed to each of the upper and lower insertion gas pads and the upper and lower discharge gas pads to control the up/down movement of each of the gas pads.
• Each of the lifting link bars may be installed pivotally on a central axis installed to a central portion of the lifting link bar;
• the lifting link bar may include a push wheel installed at one side thereof to be in contact with upper surfaces of the upper insertion gas pad and upper discharge gas pad and lower surfaces of the lower insertion gas pad and lower discharge gas pad, and a lifting wheel installed at the other side thereof to pivot together with the lifting link bar;
• a driving axis may be installed between the lifting wheels and driven by a driving unit; and a lifting cam is installed to the driving axis to be in contact with the lifting wheel to move the lifting wheel up and down.
• a guide beam may be further installed below the guide bar so that the guide bar travels forward and backward; the guide bar may be fixed to a traveling block to which a traveling wheel traveling together with the guide bar is installed; and a traveling cam may be further installed to the driving axis to be in contact with the traveling wheel to travel the traveling wheel.
• the apparatus may further include a first transfer unit disposed adjacent to the upper and lower insertion gas pads to insert the polarizing film between the upper and lower insertion gas pads; and a second transfer unit disposed adjacent to the upper and lower discharge gas pads to receive the polarizing film discharged from between the upper and lower discharge gas pads.
• the apparatus may further include a first sensor for detecting a position of the polarizing film transferred to between the upper and lower insertion gas pads; and a second sensor for detecting a position of the polarizing film transferred from the upper and lower insertion gas pads to the upper and lower discharge gas pads.
• Transfer rollers may be further installed to the first and second transfer units to transfer the polarizing film.
• a polarizing film inspection method including: supplying a polarizing film; transferring the supplied polarizing film while the supplied polarizing film is aligned flat by gas uniformly injected; inspecting the polarizing film while the polarizing film is aligned flat and transferred; and discharging the polarizing film after inspection is completed.
• the polarizing film may be kept flat by uniformly injecting gas to upper and lower surfaces thereof.
• the polarizing film may pass through between first and second gas alignment units that uniformly inject gas to the upper and lower surfaces of the polarizing film.
• Transferring the supplied polarizing film while the supplied polarizing film is aligned flat may include: allowing the first and second gas alignment units to approach each other and the first gas alignment unit to approach a polarizing film supplier to wait for insertion of the polarizing film; injecting gas from the first gas alignment unit, inserting the polarizing film into the first gas alignment unit, and then inserting a front end of the polarizing film into the second gas alignment unit; clamping the front end of the polarizing film by the second gas alignment unit and traveling the second gas alignment unit corresponding to transferring velocity and direction of the polarizing film; stopping gas supply injected from the first gas alignment unit when a rear end of the polarizing film arrives at an end of the first gas alignment unit, and clamping the rear end of the polarizing film by the first gas alignment unit; traveling the first gas alignment unit according to transferring velocity and direction of the polarizing film; releasing the clamped polarizing film from the first gas alignment unit when the first gas alignment unit arrives at the second gas alignment unit, and traveling the
• a polarizing film transferred using a conveyer passes through gas pads that inject gas uniformly, so that additional processes for aligning the polarizing film and keeping the polarizing film flat are not required.
• the polarizing film can be inspected continuously and rapidly. Accordingly, an inspection time is shortened to maximize the operation efficiency of the apparatus.
• FIG. 1 is a schematic view showing a polarizing film inspection apparatus according to an exemplary embodiment of the present invention
• FIG. 2 is a view illustrating a principle of the polarizing film inspection apparatus according to the exemplary embodiment of the present invention
• FIG. 3 is a perspective view showing a polarizing film inspection apparatus according to an exemplary embodiment of the present invention
• FIG. 4 is a front view showing the polarizing film inspection apparatus according to the exemplary embodiment of the present invention
• FIG. 5 shows an operation of the polarizing film inspection apparatus according to the exemplary embodiment of the present invention
• FIGS. 6 to 13 show operations of major portions of the polarizing film inspection apparatus according to the present invention.
• FIG. 1 schematically shows a polarizing film inspection apparatus according to an exemplary embodiment of the present invention.
• the polarizing film inspection apparatus of the exemplary embodiment includes a first transfer unit 10, first and second gas alignment units 20, a film inspection unit 40 and a second transfer unit 50.
• the first transfer unit 10 supplies a polarizing film continuously.
• the first and second gas alignment units 20 and 30 are provided near a front end of the first transfer unit 10 to be spaced apart from each other.
• Each of the first and second gas alignment units has a pair of gas pads 21a and 21b or 31a and 31b.
• the upper gas pad 2 la/3 Ia and the lower gas pad 21b/31b are arranged to face each other so that a polarizing film 1 can be transferred therebetween.
• the film inspection unit 40 is provided to inspect the polarizing film 1 being transferred from the first gas alignment unit 20 to the second gas alignment units 30.
• the second transfer unit 50 is disposed near a rear end of the second gas alignment unit 30 to receive and discharge the inspected polarizing film 1.
• the polarizing film 1 is placed on the upper surface of the first transfer unit 10.
• the first transfer unit 10 transfers the polarizing film 1 into the first and second gas alignment units 20 and 30 continuously.
• the second transfer unit 50 then receives and transfers the polarizing film 1 discharged from the first and second gas alignment units 20 and 30.
• the first and second transfer units 10 and 50 may employ any configurations capable of transferring a polarizing film.
• roll-type conveyers are employed as the first and second transfer units 10 and 50 in the exemplary embodiment.
• the first and second transfer units 10 and 50 will be referred to as the first and second conveyers 10 and 50.
• Transfer rollers 11 and 51 are respectively installed to the upper side of the front end of the first conveyer 10 and the upper side of the rear end of the second conveyer 50 so that the transfer rollers 11 and 51 respectively rotate while being in contact with an upper surface of the polarizing film 1 to transfer the polarizing film 1.
• the transfer roller 11/51 may be provided in pair to rotate in opposite directions respectively so that the polarizing film 1 passing therethrough may be transferred in contact with the transfer rollers 11 and 51.
• the first and second gas alignment units 20 and 30 are disposed between the first and second conveyers 10 and 50, more specifically, the first gas alignment unit 20 is disposed at the front end of the first conveyer 10 and the second gas alignment unit 30 is disposed at the rear end of the second conveyer 50.
• Each of the first and second gas alignment units 20 and 30 include a pair of the gas pads 21a and 21b or 31a and 31b which are arranged to vertically face each other so that the polarizing film 1 may be transferred therebetween.
• Each of the gas pads 21a, 21b, 31a and 31b of the present invention includes a plurality of gas injection holes 80 formed in any one surface thereof, and gas supplied from an additional gas supply unit is uniformly injected through the gas injection holes 80. Therefore, the polarizing film 1 can be kept flat by means of the force of the supplied gas.
• These gas pads 21a, 21b, 31a and 31b may have any configurations capable of uniformly injecting gas to a predetermined area to keep the polarizing film 1 passing through the area flat.
• a surface where the gas injection holes 80 are formed may have a larger width than the polarizing film 1.
• gases that do not give any influence on the polarizing film 1, such as air, may be used as the gas supplied to the gas pads 21a, 21b, 31a and 31b.
• air is used as the gas, but the present invention is not limited thereto.
• FIG. 2 shows a principle of the polarizing film inspection apparatus according to the exemplary embodiment.
• the flexible polarizing film 1 can be rapidly transferred while being kept flat.
• the pair of gas pads 21a and 21b or 3 Ia and 3 Ib of the first or second gas alignment unit 20 or 30 respectively move up and down to control a gap therebetween.
• the polarizing film 1 can be easily transferred through gases injected from the gas pads spaced from each other by a distance larger than a thickness of the polarizing film 1 when the polarizing film 1 passes between the gas pads 21a and 21b and between the gas pads 31a and 31b.
• the gas pads 21a and 21b or 31a and 31b approach each other to get in contact with the upper and lower surfaces of the polarizing film 1, so that bending of the front and rear ends of the polarizing film 1 can be prevented.
• the most approaching distance of each pair of the gas pads 21a and 21b or 31a and 31b is may be about the thickness of the polarizing film 1. If the gas pads 21a and 21b or 31a and 31b approach each other by a distance less than the thickness of the polarizing film 1, the gas pads 21a and 21b or 31a and 31b may cause defects such as scratches on the polarizing film 1.
• the first and second gas alignment units 20 and 30 are configured to travel in the transfer direction of the polarizing film 1 or in the opposite direction thereto. At this time, each pair of gas pads 21a and 21b or 31a and 31b disposed to vertically face each other in the first or second gas alignment unit 20 or 30 may travel together, respectively.
• the first and second gas alignment units 20 and 30 travel in the transfer direction of the polarizing film 1 or in the opposite direction thereto, and the respective gas pads 21a, 21b, 31a and 31b of the first and second gas alignment units 20 and 30 move up and down.
• the present invention may employ any configuration to allow the gas pads 21a, 21b, 31a and 31b to travel in both directions and move up and down.
• a cylinder or a rack- and-pinion may be installed to each of the gas pads 21a, 21b, 31a and 31b so that the gas pad can travel in both directions and move up and down.
• FIG. 3 is a perspective view showing a polarizing film inspection apparatus according to the exemplary embodiment of the present invention
• FIG. 4 is a front view showing the polarizing film inspection apparatus according to the exemplary embodiment of the present invention
• FIG. 5 shows an operation of the polarizing film inspection apparatus according to the exemplary embodiment of the present invention.
• the polarizing film inspection apparatus includes: upper and lower insertion gas pads 21a and 21b vertically arranged to face each other and disposed at a front end of the first conveyer 10 to move up and down and travel forward and backward; and upper and lower discharge gas pads 31a and 31b spaced apart from the upper and lower insertion gas pads 21a and 21b in a horizontal direction and vertically arranged to face each other to move up and down and travel forward and backward.
• the upper and lower insertion gas pads 21a and 21b correspond to the gas pads 21a and 21b of the aforementioned first gas alignment unit 20, and the upper and lower discharge gas pads 31a and 31b correspond to the gas pads 31a and 31b of the aforementioned second gas alignment unit 30.
• a guide bar 23 is installed in a vertical direction at each side of the first and second gas alignment units 20 and 30.
• a guide bracket 23a/23b is installed at each side of the upper/lower insertion gas pad 2 la/2 Ib so that the guide bracket 23a/23b is guided by the guide bar 23. Accordingly, up-and-down movement of the upper and lower insertion gas pads 21a and 21b can be guided.
• a lifting link bar 25a/25b is installed to each of the upper and lower insertion gas pads 21a and 21b to control the up-and-down movement thereof.
• the lifting link bar 25a/25b is installed pivotally on a central axis 24a/24b which is installed to a central portion of the lifting link bar.
• a push wheel 26a/26b is installed at one side of the lifting link bar 25a/25b.
• the push wheel 26a is installed to be in contact with an upper surface of the upper insertion gas pad 21a and the push wheel 26b is installed to be in contact with a lower surface of the lower insertion gas pad 21b.
• a lifting wheel 27a/27b is installed at the other side of the lifting link bar 25a/25b to pivot together with the lifting link bar 25a/25b.
• a restoring means such as a spring may be installed to the upper and lower insertion gas pads 21a and 21b so that the upper and lower insertion gas pads 21a and 21b may return to their original positions when the pressure is released.
• a guide bar 33 is installed in a vertical direction at each side of the upper and lower discharge gas pads 31a and 31b. Also, a guide bracket 33a/33b is installed at each side of the upper/lower discharge gas pad 31a/31bso that the guide bracket 33a/33b is guided by the guide bar 23. Accordingly, up-and-down movement of the upper and lower discharge gas pads 31a and 31b can be guided.
• a lifting link bar 35a/35b, a push wheel 36a/36b, and a lifting wheel 37a/37b are installed to the upper/lower discharge gas pad 3 la/3 Ib so that they are pivoted on and rotated around central axis 34a/34b to control the up-and-down movement of the upper and lower discharge gas pads 31a and 31b.
• the guide bar 23/33 is fixed to a traveling block 28/38, respectively, and a traveling wheel 29/39 is installed to the traveling block 28/38 to travel together with the guide bar 23/33.
• the traveling block 38 is not shown in FIG. 4 for explanation of other components.
• a guide beam 70 is further installed below the guide bars 23 and 33 to guide the traveling blocks 28 and 38 traveling in the transfer direction of the polarizing film 1 or in the opposite direction thereto.
• the traveling blocks 28 and 38 and the guide bars 23 and 33 travel forward and backward on the guide beam 70 in parallel.
• the guide brackets 23a and 23b guided by guide bar 23 travel together with the guide bar 23, by which the upper and lower insertion gas pads 21a and 21b travel together.
• the guide brackets 33a and 33b guided by guide bar 33 travel together with the guide bar 33, by which the upper and lower discharge gas pads 31a and 31b travel together.
• the polarizing film inspection apparatus of the exemplary embodiment further includes driving axes 60a and 60b driven by additional driving units 65a and 65b.
• the driving unit 65a and 65b may be an electric motor, and the motor is connected to the driving axes 60a and 60b using a belt.
• a lifting cam 6 la/6 Ib and a traveling cam 63a/63b are provided in the driving axis
• the lifting cam 61a/61b provided on the driving axis 60a/60b includes: an upper portion in contact with the lifting wheel 27a/37a which is provided on the upper insertion gas pad 21a or the upper discharge gas pad 31a; and a lower portion in contact with the lifting wheel 27b/37b provided on the lower insertion gas pad 21b or the lower discharge gas pad 31b.
• the lifting cam 6 la/6 Ib is rotated to control the up-and-down movement of the lifting wheels 27a and 27b/ 37a and 37b.
• a circumference of the lifting cam 6 la/6 Ib may be machined to have a shape which allows the gas pads 21a and 21b / 31a and 31b to appropriately move up and down corresponding to a successive transferring process of the polarizing film 1.
• a side of the traveling cam 63a/63b provided on the driving axis 60a/ 60b is in contact with the traveling wheel 29/39. Therefore, as the driving axis 60a/60b is driven, the traveling cam 63a/63b is rotated to control the travel of the traveling wheel 29/ 39.
• a circumference of the traveling cam 63a/63b may also be machined to have a shape which allows the gas pads 21a and 21b / 31a and 31b to appropriately travel corresponding to the continuous transferring process of the polarizing film 1.
• a restoring means such as a spring may be installed so that the traveling block 28/38 may return to its original position when the control of the traveling wheel 29/39 is released.
• the lifting cam 61/6 Ib and the traveling cam 63a/63b are provided together on the single driving axis 60a/60b.
• the present invention is not limited thereto. That is, two driving axes may be provided and the lifting cam 6 la/6 Ib and the traveling cam 63a/63b may be separately mounted onto driving axis, so that the lifting cam 6 la/6 Ib and the traveling cam 63a/63b can be driven separately.
• the film inspection unit 40 may be any device capable of inspecting defects of the polarizing film 1 using a reflecting method or a transmitting method. Since the reflecting method is used in this exemplary embodiment, the film inspection unit 40 is configured to include: an illuminator 41 for irradiating light to upper and lower surfaces of the polarizing film 1 at a predetermined incident angle; and a camera 43 for detecting the light reflected by the polarizing film 1 after being emitted from the illuminator 41.
• At least one illuminator 41 and at least one camera 43 may be separately installed above and below the polarizing film 1 to inspect the upper and lower surfaces thereof at the same time.
• the present invention is not limited thereto.
• any one of the upper and lower surfaces of the polarizing film 1 may be irradiated with light, so that only one surface of the polarizing film 1 may be inspected by detecting the reflected light.
• the polarizing film inspection apparatus may further include: a first sensor 90a for detecting a position of the polarizing film 1 transferred from the first conveyer 10 into the upper and lower insertion gas pads 21a and 21b; and a second sensor 90b for detecting a position of the polarizing film 1 transferred from the upper and lower insertion gas pads 21a and 21b into the upper and lower discharge gas pads 31a and 31b, whereby a position of the polarizing film 1 can be accurately detected.
• the polarizing film inspection method includes steps of: supplying a polarizing film 1 ; transferring the supplied polarizing film 1 while the supplied polarizing film 1 is aligned flat using gas which is uniformly injected; inspecting the polarizing film 1 while the polarizing film 1 is aligned flat and transferred; and discharging the polarizing film 1 after inspection is completed.
• the polarizing film 1 prepared in an appropriate size is continuously loaded to the first conveyer 10 for inspection. Additional alignment means used in a conventional alignment process such as a separate clamping unit or static electricity is not required.
• the polarizing film 1 is kept flat while passing through the first and second gas alignment units 20 and 30 which are spaced apart from each other and travel in the transfer direction of the polarizing film 1 or in the opposite direction thereto.
• the first and second gas alignment units 20 and 30 include the gas pads 21a, 21b, 31a and 31b that uniformly inject gas to both surfaces, so that the polarizing film 1 can be kept flat by the gas injected from the gas pads 21a, 21b, 31a and 31b while passing through between the gas pads 21a and 21b and between the gas pads 31a and 31b.
• FIGS. 6 to 13 show operations of major portions of the polarizing film inspection apparatus according to the exemplary embodiment of the present invention.
• the first and second gas alignment units 20 and 30 approach each other so as to receive the polarizing film 1 transferred by the first conveyer 10.
• the first gas alignment unit 20 approaches the first conveyer 10.
• the gas pads 21a and 21b of the first gas alignment unit 20 and the gas pads 31a and 31b of the second gas alignment unit 30 are spaced apart from each other to have a gap larger than the thickness of the polarizing film 1, whereby the polarizing film 1 can be inserted into the gap smoothly.
• the gas pads 21a, 21b, 31a and 31b then stand by without gas supply.
• the first sensor 90a detects it. Accordingly, the gas pads 21a and 21b of the first gas alignment unit 20 begin to inject gas, and the polarizing film 1 is inserted and transferred therebetween.
• the polarizing film 1 is continuously transferred while it is kept flat by means of the gas injected from the gas pads 21a and 21b of the first gas alignment unit 20, and finally the front end of the polarizing film 1 is inserted between the gas pads 31a and 31b of the second gas alignment unit 30.
• Step 2 since the first and second gas alignment units 20 and 30 are adjacent to each other, bending of the front end of the polarizing film 1 is prevented.
• the second sensor 90b detects that the front end of the polarizing film 1 is inserted into the second gas alignment unit 30, as shown in FIG. 8, the gas pads 31a and 31b of the second gas alignment unit 30 approach each other to clamp the front end of the polarizing film 1, so that bending of the front end of the polarizing film 1 can be prevented. Subsequently, while the front end of the polarizing film 1 is clamped, the second gas alignment unit 30 travels corresponding to a transfer velocity and transfer direction of the polarizing film 1, during which a front portion of the polarizing film 1 is inspected. (Step 3)
• the second gas alignment unit 30 stops traveling. Also, the gas pads 31a and 31b of the second gas alignment unit 30 get spaced apart from each other to release the clamping of the front end of the polarizing film 1. Then, the gas pads 31a and 31b of the second gas alignment unit 30 begin to inject gas so that the polarizing film 1 is continuously transferred, during which a central portion of the polarizing film 1 is inspected. (Step 4) [82] As the polarizing film 1 is continously transferred, the rear end of the polarizing film
• Step 5 the gas pads 21a and 21b of the first gas alignment unit 20 stop injecting gas, and the gas pads 21a and 21b of the first gas alignment unit 20 approach each other to clamp the rear end of the polarizing film 1. Thus, bending of the rear end of the polarizing film 1 is prevented. (Step 5)
• the first gas alignment unit 20 travels corresponding to the transfer velocity and transfer direction of the polarizing film 1 with the rear end of the polarizing film 1 clamped. In this way, the rear end of the polarizing film 1 can be transferred while it is kept flat. During this step, a rear portion of the polarizing film 1 is inspected. (Step 6)
• Step 7 When the first gas alignment unit 20 arrives at the second gas alignment unit 30 as shown in FIG. 12, the first gas alignment unit 20 releases the clamping of the polarizing film 1, and thus the rear end of the polarizing film 1 slips out of the first gas alignment unit 20. When the rear end of the polarizing film 1 is completely out of the first gas alignment unit 20, the first gas alignment unit 20 travels in the opposite direction to the transfer direction of the polarizing film 1 to return to a standby state of Step 1. (Step 7)
• Step 8 As shown in FIG. 13, after the rear end of the polarizing film 1 passes through the second gas alignment unit 30, the gas pads 31a and 31b of the second gas alignment unit 30 stop injecting gas, and the second gas alignment unit 30 travels in the opposite direction to the transfer direction of the polarizing film lto return to the standby state of Step 1. (Step 8)
• the film inspection unit 40 inspects the polarizing film 1 simultaneously. More specifically, the inspection is performed when the polarizing film 1 is exposed to the illuminator 41 and the camera 43 while passing through the first and second gas alignment units 20 and 30. For example, as explained above, the front portion of the polarizing film 1 is inspected in Step 3, the central portion is inspected in Step 4, and the rear portion is inspected in Step 6.
• the polarizing film 1 released from the second gas alignment unit 30 is transferred to the second conveyer 50 and then unloaded after the inspection is completed.
• a polarizing film is used in the exemplary embodiment as an example of an object to be inspected, it is not limited to the polarizing film. That is, any other material having a relatively thin sheet shape may be inspected.

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• Chemical & Material Sciences (AREA)
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• General Health & Medical Sciences (AREA)
• Immunology (AREA)
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• Liquid Crystal (AREA)
• Polarising Elements (AREA)
• Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

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• 2007
  • 2007-09-12 KR KR1020070092602A patent/KR100920222B1/ko not_active IP Right Cessation
• 2008
  • 2008-06-19 CN CN200880106624A patent/CN101802661A/zh active Pending
  • 2008-06-19 WO PCT/KR2008/003473 patent/WO2009035207A1/en active Application Filing

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