JP2008155299A - Liquid crystal panel substrate grinding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding device which preventing chipping, breaking and orientation nonuniformity of a liquid crystal panel substrate. <P>SOLUTION: The grinding device has an AE sensor for detecting vibration of the liquid crystal panel substrate and moves a grinding wheel head to separate from the liquid crystal panel substrate after stopping working of the grinding wheel head when a detection signal from the AE sensor exceeds a standard value K continuously by prescribed time. A large pressure is thereby prevented from being applied on the liquid crystal panel substrate from the grinding wheel head. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal panel substrate grinding apparatus for grinding a liquid crystal panel substrate in which a liquid crystal layer is sealed between a color filter and a TFT (Thin Film Transistor) substrate.

  Conventionally, a grinding apparatus is used as a machining apparatus for thinning a workpiece. When the workpiece is thinned using machining, the load applied to the workpiece increases as the resistance generated during machining increases.

For example, Japanese Patent Application Laid-Open No. 5-84644 has developed a vibration suppression device that automatically and appropriately suppresses vibration of a workpiece in order to prevent an increase in load on the workpiece. Japanese Patent Application Laid-Open No. 2004-243474 discloses a liquid crystal panel grinding apparatus capable of reading a grinding resistance generated when grinding the surface of a liquid crystal panel substrate in terms of the number of revolutions of a grindstone. . Japanese Patent Laid-Open No. 2000-5989 discloses a grinding apparatus that stops a grinding operation when the power consumption of a motor for rotating a grindstone exceeds a reference value.
JP-A-5-84644 JP 2004-243474 A JP 2000-5989 A

  When grinding the above-mentioned liquid crystal panel substrate, clogging of the grindstone or non-uniform contact of the grindstone with the liquid crystal panel substrate may occur. Along with this, the grinding resistance applied to the liquid crystal panel substrate by the grindstone increases. As the grinding resistance increases, the load applied to the liquid crystal panel substrate increases.

  In general, the liquid crystal panel substrate is a substrate that is liquid crystal layer sandwiched between a color filter and a TFT substrate, and thus is a very fragile substrate in terms of dynamics. Therefore, the increase in the load described above tends to cause cracking, chipping, and alignment unevenness of the liquid crystal panel substrate, which may reduce the yield of finished products such as liquid crystal display devices. This fear increases as the thickness of the liquid crystal panel substrate decreases.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to allow a liquid crystal panel substrate to be ground by a desired amount while suppressing damage to the liquid crystal panel substrate and occurrence of uneven alignment. A grinding apparatus is provided.

  Further, since the liquid crystal panel substrate is very delicate, it is difficult to shorten the grinding time by increasing the moving speed of the grindstone. Therefore, it takes a long time to grind the liquid crystal panel substrate.

  Another object of the present invention is to provide a grinding apparatus capable of shortening the grinding time of a liquid crystal panel substrate.

  Furthermore, it is very difficult to adjust the grinding amount for making the liquid crystal panel substrate very thin. Since the grinding amount greatly affects the performance of the product, a method for appropriately controlling the grinding amount is required.

  Still another object of the present invention is to provide a grinding apparatus capable of appropriately grinding a predetermined amount of grinding of a liquid crystal panel substrate.

  The grinding apparatus of the present invention includes a table on which a liquid crystal panel substrate can be installed, a grindstone head on which a grindstone for grinding the liquid crystal panel substrate can be mounted, and a rotation motor that rotates the grindstone head about an axis. . In addition, the apparatus includes a moving motor that moves the grinding wheel head in the axial direction, a controller that controls the rotating motor and the moving motor, and a sensor that converts vibration information of the grinding wheel head into an electrical signal and transmits the electrical signal to the controller. And.

  In addition, the controller according to one aspect of the present invention includes a rotation motor and a movement when the detection value of the sensor has a predetermined condition indicating that excessive pressure is applied from the grindstone head to the liquid crystal panel substrate. After stopping the motor, the moving motor is controlled so that the grindstone head is separated from the liquid crystal panel substrate.

  According to the controller of one aspect described above, if the above-mentioned conditions are set so as to prevent damage to the liquid crystal panel substrate and the occurrence of alignment unevenness, excessive pressure is applied to the liquid crystal panel substrate. Before the head is damaged, the operation of the grindstone head can be stopped and the grindstone head can be moved away from the liquid crystal panel. Therefore, it is possible to prevent the liquid crystal panel substrate from being damaged or unevenness in the orientation of the liquid crystal panel substrate.

  In the controller according to another aspect of the present invention, when the detected value has a predetermined condition indicating that the grindstone is in contact with the liquid crystal panel substrate, the grindstone head is not changed without changing the control mode of the motor for rotation. The moving motor is controlled so as to move in the axial direction at a moving speed smaller than the previous moving speed.

  According to the controller of the other aspect described above, immediately after the grindstone head contacts the liquid crystal panel substrate, the moving speed of the grindstone head is changed to a speed smaller than the previous speed. Therefore, the grindstone head can be moved at a relatively high speed until the grindstone head contacts the liquid crystal panel substrate, and after the grindstone head contacts the liquid crystal panel substrate, the grindstone head can be moved at a relatively small speed. . According to this, the time required for the entire grinding process can be shortened without damaging the liquid crystal panel substrate.

  The controller according to yet another aspect of the present invention may be configured such that a predetermined time elapses after the detection value has a predetermined condition indicating that the grindstone has contacted the liquid crystal panel substrate, or the axial movement motor is When it is determined that the grindstone head has been moved in the axial direction by a predetermined distance, after the rotation motor and the movement motor are stopped, the movement motor is controlled so that the grindstone head is separated from the liquid crystal panel substrate.

  In general, it is difficult to control the amount of grinding of the liquid crystal panel substrate to a predetermined value by the total amount of movement of the grinding wheel head in the axial direction including the amount of movement before the grindstone contacts the liquid crystal panel substrate. This is because if the size of the grindstone or the thickness of the liquid crystal panel substrate is different, the amount of grinding differs for each liquid crystal panel substrate even if the amount of movement of the grindstone head is the same. Therefore, it is desirable to control the amount of grinding of the liquid crystal panel substrate by the amount of axial movement of the grinding head after the grindstone contacts the liquid crystal panel substrate.

  According to the controller of still another aspect, the grinding amount of the liquid crystal panel substrate can be controlled based on the axial movement amount of the grinding head after the grindstone contacts the liquid crystal panel substrate. Therefore, the liquid crystal panel substrate can be ground by a desired amount without causing damage to the liquid crystal panel substrate and occurrence of uneven alignment.

  In each of the controllers of the one aspect, the other aspect, and still another aspect, the aforementioned condition is that the amplitude of the vibration of the grinding wheel head specified by the detection value of the sensor continuously exceeds the reference value for a predetermined time. It may be established if The above-mentioned condition may be satisfied when the average value of the amplitude of the vibration of the grinding wheel head specified by the detection value of the sensor within a predetermined time exceeds the reference value. The above-described condition may be satisfied when the amplitude of the vibration of the grindstone head specified by the detection value of the sensor exceeds the reference value.

Hereinafter, a grinding apparatus according to an embodiment of the present invention will be described with reference to the drawings.
(Embodiment 1)
First, a grinding apparatus according to Embodiment 1 of the present invention will be described.

  As shown in FIGS. 1 and 2, the grinding apparatus according to the first embodiment of the present invention includes a table 1. A suction jig 9 for sucking the liquid crystal panel substrate 8 is fixed to the table 1. The suction jig 9 is connected to a vacuum evacuation device, and the liquid crystal panel substrate 8 is sucked by the suction jig 9 because of the vacuum state generated by the function of the vacuum evacuation device. The table 1 is connected to a table rotating motor 2 through a rotating shaft.

  The grinding apparatus according to the present embodiment includes a grindstone head 4. A grindstone 3 for grinding the liquid crystal panel substrate 8 is mounted on the grindstone head 4. Moreover, the grindstone head 4 is attached to the rotating shaft. The grindstone head axial movement motor 6 and the grindstone head rotation motor 5 are respectively connected to the rotation shaft of the grindstone head 4 so as to be movable in the axial direction and rotatable about the axis.

  The grinding wheel head rotation motor 5, the grinding wheel head axial movement motor 6, and the table rotation motor 2 are controlled by the controller 10, respectively. The controller 10 receives a signal from an AE (Acoustic Emission) sensor 7. The AE sensor 7 is a sensor that detects the vibration of the grindstone head 4. The AE sensor 7 converts the amplitude of vibration of the grindstone head 4 into an amplitude of an electric signal proportional to the magnitude, and transmits the electric signal to the controller 10.

  In the present embodiment, the AE sensor 7 is used as a sensor that converts the amplitude of the vibration of the grindstone head 4 into the amplitude of an electric signal proportional to the magnitude thereof. Any sensor can be used in place of the AE sensor as long as the sensor can convert the amplitude of the electrical signal in proportion to the magnitude.

  As shown in FIG. 3, the controller 10 includes a grinding wheel head rotating motor driving unit, a grinding wheel head moving motor driving unit, a determination unit, a dressing stone driving unit, and a table rotating motor driving unit.

  The controller 10 rotates the table 1 in a direction indicated by an arrow A in FIG. 1 at a speed of 10 RPM to 20 RPM. Moreover, the controller 10 rotates the grindstone head 4 in the direction shown by the arrow B in FIG. 1 at a speed of 800 RPM to 1000 RPM. Furthermore, the controller 10 moves the grindstone head 4 in the axial direction at a speed of 10 μm / min to 100 μm / min to grind the liquid crystal panel substrate 8.

  When the grinding apparatus is driven, the determination unit receives an electrical signal from the AE sensor 7. Thereafter, the determination unit continues to determine whether or not the amplitude value of the vibration of the grindstone head 4 specified by the detection value of the AE sensor has exceeded the reference value for a predetermined time. When the value of the vibration amplitude of the grindstone head 4 specified by the detection value of the AE sensor in the determination unit continues for a predetermined time and exceeds a predetermined reference value, the grindstone head rotation motor drive unit and the grindstone head movement A signal instructing to stop the rotation and movement and to leave the liquid crystal panel substrate 8 is transmitted to each of the motor drive units.

  In order to prevent damage or the like of the liquid crystal panel substrate 8, whether or not the average value within a predetermined time of the amplitude of vibration of the grindstone head 4 specified by the detection value of the AE sensor 7 in the determination unit exceeds a reference value. May be determined. Also, if an extremely large pressure is applied to the liquid crystal panel substrate even for a moment, the liquid crystal panel substrate may be damaged. If the detected value of the AE sensor exceeds the reference value L even for a moment, Alternatively, the movement and rotation of the grinding head 4 may be stopped, and the grinding wheel head axial movement motor 6 may be controlled so that the grinding wheel head 4 is separated from the liquid crystal panel substrate 8. Furthermore, any determination method may be used in the determination unit as long as damage to the liquid crystal panel substrate 8 can be prevented.

  The grindstone head rotating motor driving unit and the grindstone head moving motor driving unit shown in FIG. 3 stop the grindstone head rotating motor 5 and the grindstone head axial movement motor 6, respectively, after receiving the above-mentioned command signal. Let Thereafter, the grindstone head moving motor drive unit drives the grindstone head 4 so that the grindstone head 4 is separated from the liquid crystal panel substrate 8.

  Further, a command signal is transmitted from the determination unit to the dressing stone drive unit and the table rotation motor drive unit according to the determination result of the determination unit. The dressing stone drive unit and the table rotation motor drive unit that have received this command signal control the table rotation motor 2 and the dressing stone drive mechanism 21, respectively.

  As shown in FIG. 4, the dressing stone drive mechanism 21 is a mechanism that can remove the liquid crystal panel substrate 8 from the suction jig 9 and fix the dressing stone 22 to the suction jig 9 of the table 1. It can be anything. For example, the dressing stone drive mechanism 21 is provided with a hand portion at the tip of the arm portion. The liquid crystal panel substrate 8 is gripped and removed by the hand portion, and then the dressing stone 22 is gripped and sucked by the hand portion. It may be placed on the jig 9.

  Further, the grindstone 3 is dressed by rotating the grindstone head 4 while the grindstone 3 is pressed against the dressing stone 22 mounted on the suction jig 9 of the table 1.

  Further, after the operation of the grindstone head 4 is stopped, not only the dressing of the grindstone head 4 but also the horizontal adjustment of the grindstone head 4 may be performed. Further, dressing of the grindstone head 4 and horizontal adjustment of the grindstone head 4 may be automatically performed by a mechanism such as the dressing stone driving mechanism 21 under the control of the controller 10. In addition, while the grinding apparatus is stopped, an operator may replace the dressing stone for dressing the grindstone head 4 with the liquid crystal panel substrate and perform horizontal adjustment of the grindstone head 4.

  In the present embodiment, as shown in FIG. 5, the liquid crystal panel substrate 8 has a liquid crystal layer 8b between the TFT substrate 8c, that is, a substrate in which a thin transistor is patterned on a glass substrate, and the color filter 8a. An encapsulated substrate. Of these three layers (8a, 8b, 8c), the portion to be ground by the grindstone 3 is a color filter 8a.

  When the liquid crystal panel substrate 8 is ground by the grinding apparatus, if an excessive pressure is applied to the liquid crystal panel substrate 8, the liquid crystal panel substrate 8 is not so large in mechanical strength that the liquid crystal panel substrate 8 is chipped and cracked. Further, the occurrence of alignment unevenness occurs. Therefore, in the present embodiment, if the value of the vibration amplitude of the grinding wheel head 4 specified by the signal received from the AE sensor 7 in the determination unit exceeds the reference value for a predetermined time, the controller 10 rotates the grinding wheel head. A predetermined command signal is transmitted to each of the motor 5 and the grinding wheel head axial movement motor 6 to stop the rotation of the grinding wheel head 4 and the movement of the grinding wheel head 4 in the axial direction.

  Further, after the operation of the grindstone head 4 stops, the controller 10 transmits a predetermined command signal to the grindstone head axial movement motor 6 and moves the grindstone head axially so that the grindstone head 4 moves away from the liquid crystal panel substrate 8. The motor 6 is driven. Thereby, the grindstone head 4 moves away from the liquid crystal panel substrate 8.

  Thereafter, the controller 10 causes the dressing stone drive mechanism 21 to grip the liquid crystal panel substrate 8 to move it to another position, and then mount the dressing stone on the suction jig 8 of the table 1. Thereafter, the controller 10 transmits a predetermined signal to each of the grinding wheel head rotating motor 5 and the grinding wheel head axial movement motor 6 so that the grinding wheel 3 is pressed against the dressing stone on the table 20. Move in the axial direction. Thereby, the dressing of the grindstone 3 is completed. Thereafter, in response to a command from the controller 10, the dressing stone drive unit removes the dressing stone from the suction jig 9 and executes a process for mounting the liquid crystal panel substrate 8 on the suction jig 9.

  When the grinding apparatus does not have the dressing stone drive mechanism 21, the operator can perform the exchange operation between the liquid crystal panel substrate 8 and the dressing stone.

  In FIG. 6 and FIG. 7, the value of the detection signal of the AE sensor is displayed together with the grinding time. FIG. 6 is a graph showing detection values of the AE sensor in a state where excessive pressure is not applied to the liquid crystal panel substrate 8. FIG. 7 is a graph showing the detection value of the AE sensor when an excessive pressure is applied to the liquid crystal panel substrate 8.

  As can be seen by comparing FIG. 6 and FIG. 7, a state in which an excessive pressure is applied to the liquid crystal panel substrate 8 and a state in which an excessive pressure is not applied to the liquid crystal panel substrate 8 are detected signals of the AE sensor 7. Can be distinguished by a certain threshold. Therefore, if the value of the detection signal of the AE sensor 7 exceeds a reference value, for example, 6 V, for a predetermined time, for example, 10 seconds, the controller 10 determines that an abnormal pressure has been applied to the liquid crystal panel substrate 8, and the grindstone head The rotation motor 5 and the grinding wheel head axial movement motor 6 are stopped. According to this, it is possible to prevent an excessive pressure from being applied to the liquid crystal panel substrate 8 from the grindstone 3.

  However, the detection value of the AE sensor when stopping the rotation of the grinding wheel head 4 around the axis and the movement along the axial direction and the time during which the detection value is continuously detected are not limited to the above values. Any device may be used as long as it can prevent the occurrence of problems such as damage to the liquid crystal panel substrate 8.

  Next, the grinding process performed in the controller 10 of the grinding apparatus of this Embodiment is demonstrated using FIG. In the grinding process of the present embodiment, as shown in FIG. 8, it is first determined in step S1 whether or not grinding has started. If it is determined in step S1 that grinding has not started, the process of step S1 is repeated. Note that the start of grinding is determined by the operation of the operation unit 11 by the user.

  On the other hand, if it is determined in step S1 that the grinding process has been started, a process of moving the grindstone head 4 toward the liquid crystal panel substrate 8 at a constant moving speed S is executed in step S2. That is, the controller 10 drives the grindstone head axial movement motor 6 so that the grindstone head 4 moves toward the liquid crystal panel substrate 8, and the grindstone head rotation motor so that the grindstone head 4 rotates about the axis. 5 is rotated. Thereby, the grindstone head 4 approaches the liquid crystal panel substrate 8 along the axial direction while rotating around the axis.

  Next, in step S3, it is determined whether grinding of the liquid crystal panel substrate 8 is completed. In the present embodiment, the controller 10 determines that grinding is complete when the movement distance of the grinding wheel head axial movement motor 6 reaches a predetermined value. The controller 10 may determine that the grinding of the liquid crystal panel substrate 8 has been completed when a predetermined time has elapsed since the start of grinding or immediately after the grindstone 3 contacts the liquid crystal panel substrate 8. In any case, it is determined whether or not the grinding has been completed in accordance with a criterion for determining whether or not the grinding incorporated in the controller 10 should be terminated in advance. This determination process will be described in detail in the second embodiment.

  In this determination process, if it is determined that the grinding of the liquid crystal panel substrate 8 has been completed, the controller 10 outputs signals for stopping the driving of the grinding wheel head rotating motor 5 and the grinding wheel head axial movement motor 6 respectively. Send. Thereafter, the process of step S1 is repeated again.

  On the other hand, if it is determined in step S3 that the grinding process has not been completed, it is determined in step S4 whether or not the detected value of the AE sensor 7 continues for a predetermined time and is greater than the reference value K. In step S4, if the detected value of the AE sensor 7 continues for a predetermined time and is not larger than the reference value K, the processes of S2 to S4 are repeated. On the other hand, if the detected value of the AE sensor 7 becomes larger than the reference value K for a predetermined time in step S4, the grindstone head 4 is moved away from the liquid crystal panel substrate 8 after the grindstone head 4 is stopped in step S5. Let In step 4, it may be determined whether or not the average value of the detection values of the AE sensor 7 within a predetermined time exceeds the reference value K.

  Thereafter, dressing of the grindstone 3 is performed in step S6. In the dressing of the grindstone 3, as described above, the controller 10 performs the dressing so that the liquid crystal panel substrate 8 is removed from the suction jig 9 of the table 1 and then the dressing stone is mounted on the suction jig 9. The stone drive mechanism 21 is controlled. In this state, the grindstone 3 is pressed so as to contact the dressing stone.

  In this embodiment, the dressing of the grindstone 3 shown in step S6 is automatically performed under the control of the controller 10. However, after the operation of the grindstone head 4 stops and the grindstone head 4 moves away from the liquid crystal panel substrate 8, the liquid crystal panel substrate 8 is removed from the suction jig 8 of the table 1 by the operator's manual work, and the suction jig 8 A dressing stone may be mounted on the top. In addition, after step S6 is complete | finished, the process of step S1 is performed again.

  According to the grinding apparatus of the present embodiment, in step S4, for example, the condition that the detection value of the AE sensor 7 continues for a predetermined time and becomes larger than the reference value K, and within the predetermined time of the detection value of the AE sensor 7 If either of the condition that the average value of the AE sensor 7 exceeds the reference value K and the condition that the detected value of the AE sensor 7 exceeds the reference value is satisfied, the operation of the grindstone head 4 is stopped and the grindstone head 4 is moved to the liquid crystal panel. Move away from the substrate 8. This prevents a large pressure from being applied to the liquid crystal panel substrate 8 from the grindstone head 4. Therefore, chipping and cracking of the liquid crystal panel substrate 8 and occurrence of uneven alignment of the liquid crystal panel substrate 8 are prevented.

(Embodiment 2)
Next, the grinding apparatus of Embodiment 2 of this invention is demonstrated using FIGS. 9-11. The grinding apparatus of the present embodiment is substantially the same as the grinding apparatus of the first embodiment, but differs from the grinding apparatus of the first embodiment in the grinding process shown in FIG.

  First, the problems of the conventional grinding apparatus will be specifically described. FIG. 9 shows a state before the grindstone 3 is dressed and a state after the grindstone 3 is dressed. The grindstone 3 is relatively large when not dressed. Therefore, in a grinding apparatus in which the distance between the lower surface of the grindstone head 4 and the upper surface of the table 1 at the start of grinding is constant, the distance 32 between the upper surface of the liquid crystal panel substrate 8 and the lower surface of the grindstone 3 is relative. Small.

  On the other hand, the grindstone 3 is relatively small after dressing. Therefore, in a grinding apparatus in which the distance between the lower surface of the grindstone head 4 and the upper surface of the table 1 at the start of grinding is constant, the distance 33 between the lower surface of the grindstone head 4 and the upper surface of the table 1 is relatively large. That is, the lessened grindstone 3 is positioned far from the liquid crystal panel substrate 8 by a distance 31 as compared to the undressed grindstone 3. Therefore, if the moving amount of the liquid crystal panel substrate 8 is controlled by the moving distance of the grindstone head 4, the grinding amount of the liquid crystal panel substrate 8 varies depending on the size of the grindstone 3.

  That is, in this embodiment, when the controller and the roller 10 monitor the amount of movement of the grindstone head 4 in the axial direction and control the amount of grinding of the liquid crystal panel substrate 8 based on the amount of movement, the size of the grindstone 3 is increased. If the distances are different, the grinding amount of the liquid crystal panel substrate 8 is also different.

  However, as described below, if the timing at which the grindstone head 4 contacts the liquid crystal panel substrate 8 can be detected, the liquid crystal panel is measured by measuring the axial movement amount of the grindstone head 4 calculated from the timing. The grinding amount of the substrate 8 can be controlled.

  According to this, it is possible to prevent the variation in the grinding amount of the liquid crystal panel substrate 8 caused by the variation in the size of the grindstone 3. That is, if the movement amount in the axial direction of the grindstone head 4 after the grindstone 3 comes into contact with the liquid crystal panel substrate 8 is controlled, the grinding amount for each liquid crystal panel substrate 8 can be set regardless of the size of the grindstone 3. It can be set to a substantially constant value.

  Next, a sensor for detecting the timing at which the grindstone head 4 contacts the liquid crystal panel substrate 8 will be described. FIG. 10 is a diagram for explaining that the timing at which the grindstone head 4 contacts the liquid crystal panel substrate 8 can be easily grasped using the AE sensor. As can be seen from FIG. 10, the detected value of the AE sensor 7 is almost zero before the grindstone head 4 contacts the liquid crystal panel substrate 8, but after the grindstone head 4 contacts the liquid crystal panel substrate 8, The detection value of the AE sensor rises at once.

  According to this, the timing at which the grindstone head 4 contacts the liquid crystal panel substrate 8 can be detected by the controller 10 monitoring the detection value of the AE sensor. Therefore, the controller 10 can vary the moving speed in the axial direction of the grindstone head 4 before and after the grindstone head 4 contacts the liquid crystal panel substrate 8.

  Next, the grinding process of the grinding apparatus according to the present embodiment will be described. In the grinding process of the grinding apparatus according to the present embodiment, first, in step S11, it is determined whether grinding has started. If it is not determined in step S11 that grinding has started, the processing in step S11 is repeated. Note that the start of grinding is determined by the operation of the operation unit 11 by the user. On the other hand, if it is determined in step S11 that the grinding process has been started, a process of moving the grindstone head 4 toward the liquid crystal panel substrate 8 at a constant movement speed S is executed in step S12.

  Next, in S13, it is determined whether or not the detection value of the AE sensor 7 is continuously larger than the reference value L for a predetermined time. In step S13, if the detected value of the AE sensor 7 continues for a predetermined time and is not larger than the reference value L, a process of moving the grindstone head 4 toward the liquid crystal panel substrate 8 at a constant moving speed S in step S12. Repeated.

  In order to detect that the grindstone 3 has come into contact with the liquid crystal panel substrate 8, the average value within a predetermined time of the amplitude of the vibration of the grindstone head 4 specified by the detection value of the AE sensor 7 in step S13 is determined by the determination unit. It may be determined whether or not a reference value has been exceeded. Further, if an extremely large pressure is applied to the liquid crystal panel substrate 8 even for a moment, it may be determined that the grindstone 3 has contacted the liquid crystal panel substrate 8 in step S13. Furthermore, any determination method may be used as long as it can detect that the grindstone 3 has contacted the liquid crystal panel substrate 8.

  In step S13, if the detected value of the AE sensor 7 continues for a predetermined time and is larger than the reference value L, the moving speed of the grindstone head 4 is set to a moving speed T lower than the moving speed S described above. Thereafter, in step S15, the process of moving the grindstone head 4 toward the liquid crystal panel substrate 8 at a constant moving speed T slower than the moving speed S is continued.

  Next, in step S16, it is determined whether grinding has been completed. Whether or not the grinding is completed is determined by detecting that the distance traveled by the grindstone head 4 after the grindstone 3 contacts the liquid crystal panel substrate 8 has reached a predetermined value, or whether the grindstone 3 is in the liquid crystal panel. It is desirable that this is performed depending on whether a predetermined time has elapsed after contacting the substrate 8.

  Specifically, when the grindstone 3 starts the timer immediately after the detected value of the AE sensor 7 exceeds the reference value L in step S13, and the timer counts a predetermined time in step 16, the grinding is completed. It may be determined. The reason that the completion of grinding can be recognized by such determination is that the time measured by the timer and the liquid crystal panel substrate are assumed under the assumption that the axial movement amount of the grindstone head 4 per unit time is substantially constant. This is because the grinding amount of 8 is considered to be substantially proportional. According to this, the completion of grinding can be determined without providing a further sensor for detecting the completion of grinding.

  Further, the grinding device may have a distance sensor that can measure the movement amount of the grinding wheel head 4 in the axial direction. In this case, the movement amount in the axial direction of the grindstone head 4 obtained by the distance sensor is input to the controller 10. Thereafter, in step S <b> 16, the completion of grinding is determined by the amount of movement of the grindstone head 4 after contacting the liquid crystal panel substrate 8. According to this, even when the grinding amount per unit time varies, the actual grinding amount of the liquid crystal panel substrate 8 can be accurately detected.

  If it is not determined in step S16 that the grinding of the liquid crystal panel substrate 8 has been completed, the process of step S15 for pressing the grindstone head 4 against the liquid crystal panel substrate 8 at a constant moving speed T slower than the moving speed S described above is continued. The On the other hand, if it is determined in step S16 that the grinding has been completed, the process of determining whether or not the grinding process has been started is repeated in S11.

  According to the grinding process of the second embodiment shown in FIG. 11, the detection value of the AE sensor 7 continues for a predetermined time and is larger than a value indicating that the grindstone head 4 has contacted the liquid crystal panel substrate 8. If so, the moving speed of the grindstone head 4 is set to a moving speed T lower than the moving speed S until the grindstone head 4 contacts the liquid crystal panel substrate 8.

  According to this, the grindstone head 4 is moved at a relatively large moving speed S until the grindstone head 4 contacts the liquid crystal panel substrate 8, and after the grindstone head 4 contacts the liquid crystal panel substrate 8, the liquid crystal panel substrate. The moving speed T suitable for grinding of 8 can be reduced. According to such control, it becomes possible to shorten the time required for grinding while preventing the occurrence of chipping, cracking and alignment unevenness of the liquid crystal panel substrate 8.

(Embodiment 3)
Next, a grinding apparatus according to Embodiment 3 of the present invention will be described. The grinding wheel device of the present embodiment is substantially the same as the grinding device of the first embodiment, but differs from the grinding device of the first embodiment in the grinding process shown in FIG.

  As shown in FIG. 12, it is determined in step S111 whether the grinding process has started. If it is determined in step S111 that the grinding process has not been started, the process of S111 is repeated. On the other hand, if it is determined in step S111 that the grinding process has been started, a process of moving the grindstone head 4 toward the liquid crystal panel substrate 8 at a constant moving speed S is executed in step S112.

  Next, in step S113, it is determined whether or not the detection value of the AE sensor 7 is continuously larger than the reference value L for a predetermined time. If the detected value of the AE sensor 7 is not larger than the reference value L in step S113, the process of moving the grindstone head 4 toward the liquid crystal panel substrate 8 at a constant moving speed S is continued in step S112. In step S113, if the detection value of the AE sensor 7 continues for a predetermined time and becomes larger than the reference value L, a process of reducing the moving speed of the grindstone head 4 from the moving speed S to the moving speed T in step S114. Is executed.

  The determination unit determines whether the average value within a predetermined time of the amplitude of vibration of the grindstone head 4 specified by the detection value of the AE sensor 7 in step S13 exceeds the reference value, whereby the grindstone 3 is liquid crystal. It may be detected that the panel substrate 8 is touched. Further, in step S <b> 113, it may be determined that the grindstone 3 has contacted the liquid crystal panel substrate 8 when an extremely large pressure is applied to the liquid crystal panel substrate 8 even for a moment. Furthermore, any determination method may be used as long as it can be recognized that the grindstone 3 is in contact with the liquid crystal panel substrate 8.

  Next, in step S115, it is determined whether the grinding process has been completed. If it is determined in step S115 that the grinding process has been completed, the process of step S111 is repeated. On the other hand, if it is determined in step S115 that the grinding process has not been completed, it is determined in step S116 whether or not the detected value of the AE sensor is continuously greater than the reference value K for a predetermined time. In step S116, if the detection value of the AE sensor continues for a predetermined time and is not larger than the reference value K, the processing of step S114 to step S116 is repeated. In step S116, if the detected value of the AE sensor continues for a predetermined time and becomes larger than the reference value K, the grindstone head 4 is stopped and then the grindstone head 4 is separated from the liquid crystal panel substrate 8 in step S117. Thus, the process of moving is executed.

  In order to prevent damage or the like of the liquid crystal panel substrate 8, whether or not the average value within a predetermined time of the amplitude of vibration of the grindstone head 4 specified by the detection value of the AE sensor 7 in the determination unit exceeds a reference value. May be determined. In addition, if an extremely large pressure is applied to the liquid crystal panel substrate 8 even for a moment, the detection value of the AE sensor 7 exceeds the reference value L even for a moment if the liquid crystal panel substrate 8 may be damaged. In this case, the movement and rotation of the grinding head 4 may be stopped, and the grinding wheel head axial movement motor 6 may be controlled so that the grinding wheel head 4 is separated from the liquid crystal panel substrate 8. Furthermore, any determination method may be used as long as damage to the liquid crystal panel substrate 8 can be prevented.

  Next, in step S118, a process for dressing the grindstone 3 is executed. The processing for dressing the grindstone 3 is the same as the processing for dressing the grindstone described in the first and second embodiments.

  According to the grinding process of the present embodiment described above, when the pressure is excessively applied to the liquid crystal panel substrate of the grinding apparatus of the first embodiment, the grindstone head 4 is stopped and the grindstone head 4 is moved away from the liquid crystal panel substrate 8. Both the process of moving the grindstone head 4 and the process of reducing the moving speed of the grindstone head 4 immediately after the grindstone head 4 contacts the liquid crystal panel substrate 8 are executed. Therefore, according to the grinding apparatus, both the effects of the grinding apparatus of the first embodiment and the effects of the grinding apparatus of the second embodiment can be obtained by one AE sensor.

  Whether or not the grinding performed in step S116 has been completed is determined based on whether or not the distance traveled by the grindstone head 4 after the grindstone 3 contacts the liquid crystal panel substrate 8 has reached a predetermined value, or Desirably, this is performed depending on whether or not a predetermined time has elapsed since the grindstone head 4 contacts the liquid crystal panel substrate 8.

  Specifically, as in the second embodiment, the timer is started immediately after the grindstone 3 continues the detection value of the AE sensor 7 for a predetermined time in step S113 and exceeds the reference value L. It may be determined that grinding has been completed when the timer counts a predetermined time. According to this, the completion of grinding can be determined without providing a further sensor.

  Further, as in the second embodiment, it is determined whether grinding is completed based on the value of a signal received from a distance sensor that measures the amount of movement of the grindstone head 4 after contacting the liquid crystal panel substrate 8. Also good. According to this, even when the grinding amount per unit time varies, the actual grinding amount of the liquid crystal panel substrate 8 can be accurately detected.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a top view of the grinding device of an embodiment. It is the II-II sectional view taken on the line in FIG. It is a block diagram which shows the control system of the controller of the grinding device of embodiment. It is a figure for demonstrating the table with which the dressing stone of the grinding device of embodiment was mounted | worn. It is a figure for demonstrating the structure of a liquid crystal panel substrate. It is a graph which shows the state in which the detection value of the AE sensor of the grinding device of an embodiment is a normal value. It is a graph which shows the state in which the detection value of the AE sensor of the grinding device of an embodiment is an abnormal value. 3 is a flowchart for explaining a grinding process of the grinding apparatus of the first embodiment. It is a figure for comparing the state before and after a grindstone is dressed with a dressing stone. It is a graph for demonstrating that the timing which a grindstone head contacted the liquid crystal panel board | substrate can be recognized with the detection signal of an AE sensor. 6 is a flowchart for explaining a grinding process of the grinding device of the second embodiment. 10 is a flowchart for explaining a grinding process of the grinding apparatus according to the third embodiment.

Explanation of symbols

  1 table, 2 table rotation motor, 3 grinding wheel, 4 grinding wheel head, 5 grinding wheel head rotation motor, 6 grinding wheel head axial movement motor, 7 AE sensor, 8 liquid crystal panel substrate, 8a color filter, 8b liquid crystal layer, 8c TFT substrate, 9 suction jig, 10 controller, 11 operation unit, 21 dressing stone drive mechanism.

Claims (12)

A table on which a liquid crystal panel substrate can be installed;
A grindstone head to which a grindstone for grinding the liquid crystal panel substrate can be mounted;
A rotation motor for rotating the grinding wheel head about an axis;
A motor for moving the wheel head in the axial direction;
A controller for controlling the rotation motor and the movement motor;
A sensor that converts vibration information of the grinding wheel head into an electrical signal and transmits the electrical signal to the controller;
The controller, when the detection value of the sensor has a predetermined condition indicating that excessive pressure is applied from the grindstone head to the liquid crystal panel substrate, the rotation motor and the movement motor A grinding apparatus that controls the moving motor so that the grindstone head is separated from the liquid crystal panel substrate after being stopped.   2. The grinding apparatus according to claim 1, wherein the condition is established when an amplitude of vibration of the grinding wheel head specified by a detection value of the sensor continuously exceeds a reference value for a predetermined time.   The grinding apparatus according to claim 1, wherein the condition is established when an average value of a vibration amplitude of the grinding wheel head specified by a detection value of the sensor within a predetermined time exceeds a reference value.   The grinding apparatus according to claim 1, wherein the condition is established when an amplitude of vibration of the grindstone head specified by a detection value of the sensor exceeds a reference value. A table on which a liquid crystal panel substrate can be installed;
A grindstone head to which a grindstone for grinding the liquid crystal panel substrate can be mounted;
A rotation motor for rotating the grinding wheel head about an axis;
A motor for moving the wheel head in the axial direction;
A controller for controlling the rotation motor and the movement motor;
A sensor that converts vibration information of the grinding wheel head into an electrical signal and transmits the electrical signal to the controller;
The controller, when the detected value has a predetermined condition indicating that the grindstone has come into contact with the liquid crystal panel substrate, the grindstone head has previously been changed without changing the control mode of the rotation motor. A grinding apparatus for controlling the motor for movement so as to move in the axial direction at a movement speed smaller than the movement speed of.   The grinding apparatus according to claim 5, wherein the condition is satisfied when an amplitude of vibration of the grindstone head specified by a detection value of the sensor continuously exceeds a reference value for a predetermined time.   The grinding apparatus according to claim 5, wherein the condition is established when an average value within a predetermined time of an amplitude of vibration of the grindstone head specified by a detection value of the sensor exceeds a reference value.   The grinding apparatus according to claim 5, wherein the condition is established when an amplitude of vibration of the grindstone head specified by a detection value of the sensor exceeds a reference value. A table on which a liquid crystal panel substrate can be installed;
A grindstone head to which a grindstone for grinding the liquid crystal panel substrate can be mounted;
A rotation motor for rotating the grinding wheel head about an axis;
A motor for moving the wheel head in the axial direction;
A controller for controlling the rotation motor and the movement motor;
A sensor that converts vibration information of the grinding wheel head into an electrical signal and transmits it to the controller;
The controller has a predetermined time after the detection value indicates that the grindstone has contacted the liquid crystal panel substrate, or the axial movement motor has a predetermined distance. When it is determined that the grindstone head has been moved only in the axial direction, after the rotation motor and the movement motor are stopped, the movement motor is controlled so that the grindstone head is separated from the liquid crystal panel substrate. , Grinding equipment.   The grinding apparatus according to claim 9, wherein the condition is satisfied when an amplitude of vibration of the grindstone head specified by a detection value of the sensor continuously exceeds a reference value for a predetermined time.   The grinding apparatus according to claim 9, wherein the condition is established when an average value within a predetermined time of an amplitude of vibration of the grinding wheel head specified by a detection value of the sensor exceeds a reference value.   The grinding apparatus according to claim 9, wherein the condition is satisfied when an amplitude of vibration of the grindstone head specified by a detection value of the sensor exceeds a reference value.

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