WO2006080760A1

WO2006080760A1 - An apparatus for macro inspection for flat panel display

Info

Publication number: WO2006080760A1
Application number: PCT/KR2005/003410
Authority: WO
Original assignee: Drb Fatec
Priority date: 2004-10-13
Filing date: 2005-10-13
Publication date: 2006-08-03
Also published as: KR20050089731A

Abstract

Disclosed herein is an apparatus for the macro inspection of flat panel displays. Utilizing an articulated robot having six or more degrees of freedom, the apparatus enables examination of the surface condition of flat panel displays accurately in a short time period and enjoys the advantage of shortening the tact time of product manufacture, reducing manpower, and decreasing the production cost.

Description

AN APPARATUS FOR MACRO INSPECTION FOR FLAT

PANEL DISPLAY

Technical Field

[1] The present invention relates to an apparatus for the macro inspection of flat panel displays. More particularly, the present invention relates to an apparatus based on articulated robot arms having six or more degrees of freedom, capable of conducting macro inspection of flat panel displays rapidly and accurately.

[2]

Background Art

[3] For detecting defects in glass substrates for use in flat panel displays, such as liquid crystal displays, which are becoming more and more popular, there are micro and macro inspection systems currently in use. In a macro inspection system, defects are detected by visually observing an optical change in the light reflected upon illuminating a glass substrate with light. The defects detected in the micro inspection are optically magnified with a microscope for a close examination in a micro inspection system.

[4] To date, various sizes of glass substrates, used as screens of flat panel displays, including 1100xl200mm2 (first generation), 1100xl250mm2 (second generation), 1100xl300mm2 (third generation), 1200xl300mm2 (fourth generation), 1500xl800mm2 (fifth generation), 1500xl850mm2 (sixth generation), 1870x2200mm2 (seventh generation), 2160x2460mm2 (eighth generation) and 2400x2800mm2 (ninth generation), have been manufactured, and extensive efforts are now being made to enlarge the size of glass substrates, aiming at the production of high-quality large screens.

[5] Increasing the sizes of the glass substrates, which are the largest parts of flat panel displays, requires the dimensions and specifications of the equipment and tools used in each process to be adjusted thereto. In addition, an increase also in the weight of the glass substrates makes it difficult for operators to manually carry or handle them, thereby causing problems, such as increased production time period, more manpower, increased production costs, etc.

[6] In each step of the manufacturing process, macro inspection is performed by visually observing the light reflected from the surface of a glass substrate which is held by a tray moving on rails under illuminating light so as to detect surface defects of the glass substrates.

[7] To execute this process, apparatuses currently used in the macro inspection of flat panel displays have highly complex mechanical constitutions and occupy a lot of working space. In addition, currently used apparatuses are very inconvenient due to their inability to illuminate glass substrates at various angles with an illuminant, therefore the operator must move around the glass substrates. Accordingly, it is difficult to conduct the inspection accurately and rapidly. Further, the conventional apparatuses suffer from additional disadvantages of increasing the tact time of product manufacture, requiring more manpower, and increasing the possibility of accidents because the operators themselves sometimes carry out transportation and attachment work, such as loading glass substrates onto an inspection apparatus or unloading therefrom.

[8]

Disclosure of Invention Technical Problem

[9] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an apparatus for the macro inspection of panels for flat panel displays, which enables examination of the surface condition of the panels accurately in a short time period using an articulated robot having six or more degrees of freedom.

[10]

Technical Solution

[11] In order to accomplish the above object, the present invention provides an apparatus for the macro inspection of flat panel displays, comprising an articulated robot structured to be able to move in all directions and comprising: a lower base (10) for supporting the weight of the articulated robot (100) and maintaining the balance thereof; an upper base (20), mounted on the lower base (10), capable of rotating in a horizontal plane with respect to the lower base (10); a 1st arm (30) capable of swinging in a vertical plane, with engagement with a linker (26) which extends from a side of the upper base (20); a 2nd arm (40), mechanically engaging with one side of the 1st arm (30), capable of swinging in the plane defined by the movement of the 1st arm; a 2ath arm (40a), mounted on an end of the 2nd arm (40), capable of rotating around the longitudinal axis of the 2nd arm (40); a 3rd arm (50), mounted on an end of the 2ath arm (40a), capable of swinging in a plane parallel to the longitudinal axis of the 2ath arm; a 3ath arm (50a), mounted on an end of the 3rd arm (50), capable of rotating around the longitudinal axis of the 3rd arm (50); a holder (70), mounted on the end of a 3ath arm (50a), for holding a glass substrate (60) thereon; and a joystick unit (82) for generating control signals to operate the articulated robot (100) in such a controlled manner as to conduct the macro inspection of the glass substrate (60). [12]

Advantageous Effects

[13] Utilizing an articulated robot having six or more degrees of freedom, the apparatus for the macro inspection of flat panel displays is designed to reduce the number of working processes so that it enables examination of the surface condition of flat panel displays accurately in a short time period and enjoys the advantage of shortening the tact time of product manufacture, reducing manpower, and decreasing the production cost. [14] In addition, the apparatus according to the present invention allows the operator to readily conduct observation at various angles from a predetermined inspection position with a joystick and thus to be protected from safety accidents and musculoskeletal system disorders. [15]

Brief Description of the Drawings [16] FIG. 1 is a schematic perspective view showing a preferable embodiment of an apparatus for the macro inspection of flat panel displays in accordance with the present invention; [17] FIG. 2 is a schematic perspective view showing an articulated robot employed in the macro inspection apparatus for flat panel displays in accordance with the present invention; [18] FIG. 3 is a schematic perspective view showing the operation of an articulated robot employed in the macro inspection apparatus for flat panel displays in accordance with the present invention; [19] FIGS. 4 to 6 are cross sectional views showing inner structures of the articulated robot employed in the macro inspection apparatus for flat panel displays in accordance with the present invention; [20] FIG. 7 is a schematic perspective view showing another embodiment of an apparatus for the macro inspection of flat panel displays in accordance with the present invention; [21] FIGS. 8 to 12 are exemplary views showing the sequential operation processes of the apparatus for the macro inspection of flat panel displays in accordance with the present invention. [22]

Best Mode for Carrying Out the Invention [23] Reference should now be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components. [24] FIG. 1 schematically shows a preferred embodiment of an apparatus for the macro inspection of flat panel displays, in a perspective view, FIG. 2 schematically shows an articulated robot used in the apparatus, in a perspective view, FIG. 3 shows the operational states of the articulated robot in a perspective view, FIGS. 4 to 6 schematically show the inner structures of the articulated robot in plan views, FIG. 7 schematically shows another preferred embodiment of the apparatus for the macro inspection of flat panel displays, in a perspective view, and FIGS. 8 to 12 show a sequence of working processes of the apparatus in exemplary views. As seen in the drawings, the apparatus for the macro inspection of flat panel displays comprises an articulated robot structured to be able to move in all directions, including a lower base (10) for supporting the weight of the articulated robot (100) and maintaining the balance thereof, an upper base (20), mounted on the lower base (10), capable of rotating in a horizontal plane with respect to the lower base (10), a 1st arm (30) capable of swinging in a vertical plane, with engagement with a linker (26) which extends from one side of the upper base (20), a 2nd arm (40), mechanically engaging with one side of the 1st arm (30), capable of swinging in the plane defined by the movement of the 1st arm, a 2ath arm (40a), mounted on an end of the 2nd arm (40), capable of rotating around the longitudinal axis of the 2nd arm (40), a 3rd arm (50), mounted on an end of the 2ath arm (40a), capable of swinging in a plane parallel to the longitudinal axis of the 2ath arm, a 3ath arm (50a), mounted on an end of the 3rd arm (50), capable of rotating around the longitudinal axis of the 3rd arm (50), a holder (70), mounted on the end of a 3ath arm (50a), for holding a glass substrate (60) thereon, and a joystick unit (82) for generating control signals to operate the articulated robot (100) in such a controlled manner as to conduct the macro inspection of the glass substrate (60); an illuminating system including vertical lighting and a backlight unit for irradiating the glass substrate with light of a desired color at a desired luminous intensity; a microscope for allowing surface defects of the glass substrate on the holder (70) to be examined more precisely; a gantry for supporting and carrying the microscope; a TV camera and light lamps; and a controlling unit for controlling the actuators of the illuminating unit and the microscope.

[25]

[26] Below, a detailed description will be given of the constitution of the invention.

[27] FIG. 1 schematically shows the constitution of a preferable embodiment of the apparatus for the macro inspection of flat panel displays, according to the present invention, which is largely divided into an articulated robot (100), a holder (70), a main controller (80) and a joystick unit (82).

[28] Structured to swing horizontally or vertically or rotate around six axes, the articulated robot (100) can change its position in all directions. [29] As shown, the holder (70) is mounted on the end of a 3ath arm (designated as numeral "50a" in FIG. 2) in the articulated robot (100). The holder (70) comprises a flat panel larger than a glass substrate (60), with a plurality of absorption holes formed thereon. Once it is loaded on the holder, the glass substrate (60) can be fixed thereonto by vacuum via the absorption holes.

[30] Via a control signal line (81), a connection is obtained between the main controller

(80) and the articulated robot (100) and between the main controller (80) and the joystick unit (82).

[31] In the articulated robot (100), the holder (70) may be arranged in the 6 o'clock direction with respect to an inspector. Alternatively, the holder (70) may be in the direction of 12, 3 or 9 o'clock for the purpose of securing a wide view of the inspector or for the working convenience of the inspector. That is, as shown in FIG. 1, when the articulated robot (100) is installed, the holder (70) may be connected after a 1st arm (30) or the 3ath arm (50a) is positioned at an angle of zero, 90, 180 or 270 degrees with respect to the inspector. Alternatively, the holder (70) may be attached in a desired direction by turning a rotatable 2ath arm (40a) such that the holder (70) is allowed to hold a lower, an upper or a lateral portion of the glass substrate (60).

[32] FIGS. 2 and 3 show the articulated robot (100) according to the present invention, and the rotation axes of the articulated robot (100), respectively, in schematic perspective views, and FIGS. 4 to 6 show the inner structure of the articulated robot (100) in cross sectional views. As seen in these figures, the articulated robot (100) is structured to comprise a lower base (10), positioned in contact with the ground, for supporting the weight of the articulated robot (100) and maintaining the balance thereof, an upper base (20) capable of rotating in a horizontal plane, with connection to an upper portion of the lower base (10), a 1st arm (30) capable of swinging in a vertical plane, with connection to a linker (26) which extends from one side of the upper base, a 2nd arm (40) capable of swinging in a vertical plane, with engagement with one side of the 1st arm (30), and a 3rd arm (50) capable of swinging in a plane parallel to the movement of the 2nd arm and engaged to an end of the 2nd arm.

[33] To operate in six or more axes, the articulated robot (100) is driven using gears. The operational mechanism of the articulated robot (100) will be described in brief, with focus on the revolution or swing mechanisms in the six axes.

[34] With regard to the rotation mechanism of a first axis (A), a first-axis driving motor

(12) mounted in the upper base (20) is engaged with a first-axis reducer (14) installed in the lower base (10) so that the upper base (20) is rotated in a horizontal plane as the first- axis driving motor (12) turns because the lower base (10) coupled with the first- axis reducer (14) is fixed to the ground.

[35] A second axis (B) rotates according to the following mechanism. A second-axis reducer (23) installed in the linker (26) is coupled, through gear engagement, with a second- axis driving motor (22) internally mounted in the 1st arm (30) so that the 1st arm (30) swings in a vertical plane with the rotation of the second-axis driving motor (22) because the linker (26) associated with the second-axis reducer (23) is fixed to the upper base (20).

[36] As for the rotation mechanism of a third axis (C), the gear engagement between a third-axis driving motor (32) installed in the 1st arm (30) and a neighboring third- axis reducer (33) installed in the 2nd arm (40) makes it possible for the 2nd arm (40) to be swung in a vertical plane by the third-axis driving motor (32).

[37] The rotation mechanism of a fourth axis (D) is elucidated in FIG. 4. As a fourth- axis driving motor (42) which is mounted at an end of the 2nd arm (40) operates to drive a fourth-axis gear train (44) coupled thereto, a fourth-axis reducer (43) engaged with the fourth-axis gear train (44) rotates. Because the 2ath arm (40a) has the fourth- axis reducer (43) fixed therein, the 2ath arm (40a) turns around with the rotation of the fourth- axis reducer (43).

[38] A fifth axis (E) turns according to the mechanism elucidated in FIG. 5. When a fifth-axis driving motor (52) mounted at an end of the 2nd arm (40) operates to rotate a fifth-axis gear train (54), the power is transmitted via a fifth-axis shaft (55) to a fifth- axis bevel gear train (56) which thus turns correspondingly, leading to the rotation of a fifth-axis reducer (53) coupled to the bevel gear train (56). In response to the rotation of the fifth-axis reducer (53), the 3rd arm (50) swings in a plane vertical to the plane of rotation of the motor because it has the fifth-axis reducer (53) fixed thereto.

[39] With reference to FIG. 6, an explanation is given of the rotation mechanism of a sixth axis (F). As seen in this schematic view, a sixth-axis driving motor (62) mounted at an end of the 2nd arm (40) operates to rotate a sixth-axis first gear train (64). This power is transmitted via a sixth-axis shaft (65) so as to rotate a sixth-axis first bevel gear train (66) and a sixth-axis second gear train (67) coupled with the bevel gear train (66). Accordingly, a sixth-axis second bevel gear train (68), engaged with the sixth- axis second gear train (67), rotates, causing the rotation of a sixth-axis reducer (63). A 3ath arm (50a) turns around in response to the rotation of the sixth-axis reducer (63), which is internally installed in the 3ath arm (50a).

[40] As such, the articulated robot (100) can work within the operational ranges set forth in each of the first- to the sixth-axis driving motors and the first- to the sixth-axis reducers, thus having six degrees of freedom in total. Each part of the articulated robot (100) is connected via a control signal line (81) to the main controller (80) from which a control signal line (81) is divergent into the joystick unit (82).

[41] The joystick unit (82) is placed in a predetermined position convenient for the operator to conduct the macro inspection of the glass substrate (60). Control signals are generated according to the manipulation of the joystick by the operator and are transmitted via the control signal line (81) to the main controller (80). According to the control signals from the joystick unit (82), the main controller (80) generates control signals for the operation of each part of the articulated robot (100), that is, the driving motors (12) (22) (32) (42) (52) and (62), the arms (30) (40) (40a) (50) and (50a) and the holder (70) and transmits the signals via the signal controller line (81).

[42] The motors of the articulated robot (100) operate in response to the control signals input via the control signal line (81) so as to locate the arms (30) (40) (40a) (50) and (50a) and the holder (70) in directions and at positions as indicated by the manipulation of the joystick by the operator. Through the operation of the motors and the arms, the glass substrate (60) on the holder (70) positioned at an end of the 3ath arm (50a) of the articulated robot (100) can be moved to three-dimensional coordinates convenient for the operator to conduct macro inspection. In addition, response signals according to the operation are returned to the main controller (80) in such a feedback manner as to conduct the operation of the articulated robot (100) accurately.

[43] An apparatus for the macro inspection of flat panel displays in accordance with another embodiment of the present invention is shown in FIG. 7. This apparatus features a rail transportation (15) provided on the bottom of the lower base (10). The rail transportation unit (15) engages with a robot carriage rail (90) fixed on the ground and runs back and forth along the rail in a sliding motion, which corresponds to a seventh axis (G). The robot carriage rail (90) may be optionally installed according to the work environment.

[44] Turning now to FIGS. 8 to 11, the operation of the apparatus for the macro inspection of flat panel displays is shown as an example in process order. The macro inspection system according to the present invention comprises an illuminant (85), positioned at one side of the system, for emitting collimated light for inspecting the surface of the glass substrate (60), and a reflection light source (84), positioned at one side of the system, for emitting light onto a reflection plate (84) which functions to reflect incident light downwards.

[45] A vertical lighting and backlight unit comprising the reflection light source (84), the illuminant (85), and the reflection plate (86) is provided to irradiate the glass substrate with light of a desired color at a desired luminous intensity. This illuminating unit is a special illuminator for generating and illuminating light suitable for the effective detection of various surface marks or defects, such as scratches or blurs created during chemical treatment or cleansing processes. The illuminating unit can be controlled with respect to luminance range, wave band, focused/scattered light, and focal length according to the variable position of the glass substrate (60) so as to require only minimal movement of the inspector during the examination of the glass substrate. The illuminating light can be provided in a focused or scattered mode by running the light from a mobile light source through a large Fresnel lens to focus it and by utilizing miracle glass.

[46] The apparatus for macro inspection in accordance with the present invention may comprise a microscope unit for more precisely examining defects on the glass substrate loaded on the holder (70), a display unit for displaying the defects, and a gantry for supporting and carrying light lamps. Actuators for the light lamps and the microscope unit may be under the control of the main controller (80) of FIG. 1.

[47] The microscope unit, which enables defects, if detected with the naked eye, to be precisely observed and stores the information therein, comprises an actuator for moving the microscope unit in all directions so as to maintain a proper distance from the glass substrate. Additionally, the microscope unit is equipped with a CCD camera capable of zooming and displaying pictures on a monitor, and a control unit for storing and controlling images and location information of defects.

[48] Now, the operation of the apparatus for the macro inspection of flat panel displays, in accordance with the present invention, is explained in working order with reference to the drawings.

[49] First, as shown in FIG. 8, the glass substrate (60) is loaded onto the holder (60) and fixed thereto by a vacuum. While the light from the vertical lighting and backlight unit is radiated on the glass substrate (60), the inspector examines the surface of the glass substrate (60) by visual detection of the light reflected from the glass substrate (60).

[50] Then, the second- axis driving motor (22) is operated to direct the 1st arm downwards whereas the third-axis driving motor (32) and the fifth-axis driving motor (52) are operated in concert to direct the 3rd arm (50) upwards to incline the glass substrate (60) and face the surface of the glass substrate (60) toward the inspector, as shown in FIG. 9.

[51] In order to further incline the glass substrate (60) in the correct direction, the 1st, the 2nd, and the 3rd arms (30), (40), (50) turns independently and in concert to lift the holder (70) as shown in FIG. 10.

[52] For the inspector to have a view of the glass substrate (60) from its side, as shown in FIG. 11, the 3ath arm (50a) connected with holder (70) turns around to move the glass substrate (60).

[53] After the completion of such a sequence of macro inspection processes, the apparatus may be returned to a default position, as shown in FIG. 12.

[54] As a matter of course, the inspector can conduct the macro inspection suitably according to working condition by inputting data signals into the main controller (80) or handling the joystick unit (82).

[55] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

[1] An apparatus for the macro inspection of flat panel displays, comprising an articulated robot structured to be able to move in all directions and comprise: a lower base (10) for supporting the weight of the articulated robot (100) and maintaining the balance thereof; an upper base (20), mounted on the lower base (10), capable of rotating in a horizontal plane with respect to the lower base (10); a 1st arm (30) capable of swinging in a vertical plane, with engagement with a linker (26) which extends from one side of the upper base (20); a 2nd arm (40), mechanically engaging with one side of the 1st arm (30), capable of swinging in a plane defined by movement of the 1st arm; a 2ath arm (40a), mounted on an end of the 2nd arm (40), capable of rotating around a longitudinal axis of the 2nd arm (40); a 3rd arm (50), mounted on an end of the 2ath arm (40a), capable of swinging in a plane parallel to a longitudinal axis of the 2ath arm; a 3ath arm (50a), mounted on an end of the 3rd arm (50), capable of rotating around the longitudinal axis of the 3rd arm (50); a holder (70), mounted on the end of the 3ath arm (50a), for holding a glass substrate (60) thereon; and a joystick unit (82) for generating control signals to operate the articulated robot (100) in such a controlled manner as to conduct macro inspection of the glass substrate (60).

[2] The apparatus according to claim 1, wherein the 2ath arm (40a) has a fourth-axis reducer (43) fixed therein, and turns around as a fourth-axis driving motor (42) coupled to a fourth-axis gear train (44) operates, the fourth-axis gear train being engaged with the fourth- axis reducer.

[3] The apparatus according to claim 1, wherein the 3rd arm (50) has a fifth-axis reducer (53) fixed therein, and turns around as a fifth-axis driving motor (52) coupled to a fifth-axis gear train (56) operates, the fifth-axis gear train being engaged via a fifth-axis power-transmitting shaft (54) with a bevel gear train (56) connected to the fifth- axis reducer (53).

[4] The apparatus according to claim 1, wherein the 3ath arm (50a) has a sixth-axis reducer (63) fixed therein, and turns around as a sixth-axis driving motor (62) coupled to a sixth-axis first gear train (64) operates, the sixth-axis first gear train (64) being connected via a sixth-axis power-transmitting shaft (65) to a sixth-axis first bevel gear train (66) which is engaged with a second gear train (67), the sixth-axis reducer (63) being coupled to a sixth-axis second bevel gear train (67) which is engaged with the second gear train (67).

[5] An apparatus according to claim 1, wherein the lower base (10) is provided with a rail transportation unit (15) on its bottom, the rail transportation unit (15) engaging with a robot carriage rail (90) and running back and forth along the rail in a sliding motion.]

[6] An apparatus according to claim 1, wherein the holder (70) has a plurality of absorption holes (71) formed thereon, which function to fix the glass substrate (60) onto the holder by creating an air vacuum therethrough.