JP2003148941A - Crack detecting device, and backing line using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device that can detect cracks of a glass substrate during conveyance of the glass substrate. SOLUTION: This device for detecting cracks of a glass substrate conveyed by a conveying system having a conveyer in its midway is provided with laser displacement sensors L1 , L2 , L3 set in positions capable of measuring the cracks of the glass substrate G under the condition where the glass substrate is conveyed by the conveyer C, and a signal processing means for extracting only crack portions of the glass substrate G out of outputs of the sensors L1 , L2 , L3 . The cracks a, b in the glass substrate G are detected by the laser displacement sensors to detect the cracks generated in the glass substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting the presence or absence of cracks in a glass substrate, and in particular, a glass used for examining the presence or absence of cracks in a large glass substrate as an electronic component such as a plasma display panel. The present invention relates to a board crack detection device.

[0002]

2. Description of the Related Art Generally, a glass substrate as an electronic component such as a substrate for a plasma display panel has a large number of constituent elements such as electrodes and ribs formed thereon. Is done. Specifically, prepare a heat-resistant setter that does not soften even during firing,
The glass substrate placed on the glass substrate is passed through the firing furnace, which prevents thermal deformation of the glass substrate and also prevents damage due to contact with the transport system. Recently, automatic processing using a robot or the like is generally used for placing the glass substrate on the setter or transferring the glass substrate from the setter.

[0003]

In the above glass substrate baking step, there is a possibility that the glass substrate may break after baking. Therefore, conventionally, in order to check for cracks, workers constantly monitor the glass substrates being transported,
When a crack was found, it was disposed of. However, due to improvements in production speed and unmanned operation, it has become essential to automatically detect cracks in the glass substrate and activate alarms.

The present invention has been made in view of the above background, and an object of the present invention is to provide a glass substrate breakage detecting device capable of detecting a breakage of a glass substrate during transportation. It is to provide a firing line using the same.

[0005]

In order to achieve the above object, a crack detecting device of the present invention is a device for detecting cracks in a glass substrate being conveyed by a conveying system in which a conveyer is in the middle, A laser displacement sensor installed at a position where the glass substrate can be measured for cracks while the glass substrate is being conveyed by the conveyor, and signal processing means for extracting only the cracked portion of the glass substrate from the output of the laser displacement sensor. It is characterized by having.

In order to achieve the same object, the crack detecting device of the present invention detects cracks in a glass substrate being conveyed by a conveying system having a direction changing conveyor for changing the conveying direction to the intersecting direction. The total number of devices installed at positions where the glass substrate can be measured for cracks at two locations while the glass substrate is being conveyed in each direction intersecting on the direction change conveyor.
It is characterized by having one laser displacement sensor and a signal processing means for extracting only the cracked portion of the glass substrate from the outputs of those laser displacement sensors.

The firing line of the present invention is arranged so as to connect the firing furnace body for firing the glass substrate while the glass substrate is carried on the heat-resistant setter and the inlet and outlet of the firing furnace body. Baking line equipped with a setter transfer conveyor, a substrate supply means for placing a glass substrate before firing on the setter in the middle of the setter transport conveyor, and a substrate receiving means for transferring the glass substrate after firing from the setter In the above, the crack detection device is installed between the exit of the firing furnace main body and the substrate receiving means in the setter transport conveyor.

In the above firing line, it is preferable that when a crack in the glass substrate is detected, the operation of transferring the broken glass substrate from the setter is not performed and an alarm is issued.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings by using specific examples.

The carrying system shown in FIG. 1 has a direction changing conveyor C for changing the carrying direction of the glass substrate G carried from the X direction to the Y direction intersecting with the glass substrate G. The crack detection device of the present invention is preferably applied to a transport system having such a direction changing conveyor, but is not particularly limited.

In the example shown in FIG. 1, three laser displacement sensors L ₁ , L ₂ and L are provided above the direction changing conveyor C for converting the conveying direction into the orthogonal direction and at the positions shown in the figure.
₃ are installed. That is, while the glass substrate G placed on the setter S is being conveyed in the X direction and the Y direction on the direction changing conveyor C, the glass substrate G is set at a position where the crack of the glass substrate G can be measured at each of two positions. ing. And those laser displacement sensors L
_It has signal processing means for extracting only the broken portion of the glass substrate G from the outputs of ₁ , L ₂ and L ₃ .

When the carrying direction changes from the X direction to the Y direction as described above, the carrying level of the setter S may change. In such cases, the sensor L ₁ must detect cracks during transport in both the X and Y directions. In that case, it is desirable to be able to change the sensor height automatically.

Generally, the cracks that occur in the glass substrate are lateral cracks a or vertical cracks b as shown in FIG. Then, as shown in FIG. 2A, when conveyed in the X direction on the direction changing conveyor C, the lateral crack a passes below the _two laser displacement sensors L ₁ and L ₂ , This lateral crack a can be measured. In addition, as shown in FIG. 2B, when the direction change conveyor C is conveyed in the Y direction, the vertical crack b passes below the two laser displacement sensors L ₁ and L ₃ . This vertical crack b can be measured. Then, the laser displacement sensor sends the outputs of L ₁ , L ₂ and L ₃ to the signal processing means to generate a position signal, and the presence / absence of a crack is determined by this position signal. FIG. 3 is a graph showing an example of a position signal obtained on a glass substrate having a crack, and a part α in this graph shows a portion having a crack.

The cracks in the glass substrate G are not limited to the raw glass, but also in the glass substrate on which various constituent elements are formed such as the substrate of the plasma display panel, the height of these constituent elements is higher than the depth of the crack. Since it is relatively small, it is possible to measure with a laser displacement sensor by setting the reacting displacement to be large. In the actual operation, as shown in the graph of FIG. 3, the laser displacement sensor also reacts on the outer peripheral portion of the glass substrate. Therefore, by performing a process that cancels the reaction of that portion, the glass substrate is cracked. It is preferable to detect only one.

FIG. 4 is a plan view schematically showing an example of a baking line in which the above-mentioned crack detection device is installed. The illustrated baking line is used for baking a glass substrate of a plasma display panel. .

In FIG. 4, reference numeral 10 denotes a firing furnace main body for firing a glass substrate while transporting the glass substrate placed on a heat-resistant setter S, and heats the glass substrate G together with the setter S from room temperature to a peak temperature. A heating unit for heating and a cooling unit for returning to normal temperature are provided thereafter. Then, a setter transport conveyor 20 is arranged so as to connect the inlet 11 and the outlet 12 of the firing furnace body 10, and the setter transport conveyor 20 is located near the inlet of the firing furnace body 10 and is a glass before firing. A substrate supply means 30 for mounting the substrate G on the setter S and a substrate receiving means 40 for transferring the glass substrate G after firing from the setter S are provided.

The setter conveyor 20 is a setter S.
In order to circulate and use the above, six conveyors C _{1 to} C ₆ are connected from the outlet 12 to the inlet 11 of the firing furnace body 10. Also, the substrate supply means 30 and the substrate reception means 4
0 is arranged adjacent to the conveyor C ₅ , and the setter S stops at these two positions on the conveyor C ₅ for a predetermined time in order to transfer the glass substrate G. Then, three laser displacement sensors constituting the crack detecting device are installed above the direction changing conveyor C ₀ located at the corners of the conveyors C ₃ and C _{4 in} the same arrangement pattern as shown in FIG.

In the firing apparatus shown in FIG. 4, the firing furnace body is
The setters S are arranged in a line in 10 to burn the glass substrate G.
The processing is performed. Then, the setter transport conveyor 20
Then, the second conveyor C₂Is transported quickly at
Conveyor C₃And conveyor C_FourDirection change in the corner of
Conveyor C₀Check for cracks in glass substrate G
To be done. And normally, there is no crack in the glass substrate G.
And the fifth conveyor C _FiveThe board is delivered at
Be seen. That is, the fifth conveyor C_FiveThen first
Ter S is stopped at the substrate receiving means 40 for a predetermined time.
In the meantime, the glass substrate G after firing is set by a robot by a robot.
Transfer from above. Then the substrate in the empty state
Proceed to the supply means 30, and then again for a predetermined time
The glass substrate G before firing is stopped by the robot while it is stopped.
Mounted on the setter S, with the glass substrates G stacked
And the next 6th conveyor C₆Be transported to.

The glass substrate G of the plasma display panel is not free from cracks during firing.
The crack may be, for example, a lateral crack a or a vertical crack b as shown in FIG. If there is such a crack, the robot of the substrate receiving means 40 cannot hold it when it is transferred from C ₅ on the conveyor, and the fragments are scattered on the transfer conveyor to stop the work. In order to prevent such a situation, when a crack is detected by the crack detection device installed at the direction changing conveyor C ₀ , the operation of the robot is interrupted and the operation of transferring the broken glass substrate G from the setter S is performed. Do not do it. Then, in order to perform a quick process, it is preferable to issue an alarm.

Although the embodiments of the present invention have been described above, the crack detecting device and the firing line using the same according to the present invention are not limited to the above-described embodiments, and the gist of the present invention is not limited. It goes without saying that various modifications can be made without departing from the range.

[0021]

According to the invention as set forth in claim 1, the breakage detecting device is a device for detecting breakage of a glass substrate being conveyed by a conveying system in which a conveyer conveys the glass substrate by the conveyer. It is characterized by having a laser displacement sensor installed at a position where the crack of the glass substrate can be measured while being conveyed, and a signal processing means for extracting only the broken portion of the glass substrate from the output of the laser displacement sensor. Therefore, the crack can be detected during the transportation of the glass substrate.

A crack detecting device according to a second aspect of the present invention is a device for detecting a crack in a glass substrate being conveyed by a conveying system having a direction changing conveyor for changing the conveying direction to the intersecting direction. Then, in the state where the glass substrate is conveyed in each direction intersecting in the direction change conveyor, a total of three laser displacement sensors installed at positions where the cracks of the glass substrate can be measured at two points, respectively, and their lasers. Since it is characterized by having a signal processing means for extracting only the cracked portion of the glass substrate from the output of the displacement sensor, cracks in any direction on the glass substrate can be detected by any of the laser displacement sensors. The sensor can reliably detect cracks occurring in the glass substrate.

In the firing line according to the present invention, the firing furnace main body performs the firing of the glass substrate while the glass substrate is placed on the heat-resistant setter, and the inlet of the firing furnace main body. A setter conveyer arranged to connect the outlet, a substrate supply means for placing a glass substrate before firing on the setter in the middle of the setter conveyer, and a substrate for transferring the glass substrate after firing from the setter In a firing line equipped with a receiving means, the crack detection device having the above-mentioned configuration is characterized by being installed between the exit of the firing furnace main body of the setter transport conveyor and the substrate receiving means. Even if a crack occurs, the presence or absence of the crack can be detected during the transportation. Then, when the crack of the glass substrate is detected, the operation of transferring the broken glass substrate from the setter is not performed,
In addition, by configuring to issue an alarm, it is possible to prevent the broken glass substrate from scattering and prevent a situation in which work is stopped and productivity is reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an installation example of three laser displacement sensors that constitute a crack detection device of the present invention.

FIG. 2 is an explanatory diagram showing a method of detecting cracks in a glass substrate by a laser displacement sensor installed as shown in FIG.

FIG. 3 is a graph showing an example of a position signal obtained on a glass substrate having a crack.

FIG. 4 is a plan view schematically showing an example of a firing line in which a crack detection device is installed.

[Explanation of symbols]

G glass substrate L ₁ , L ₂ , L ₃ laser displacement sensor S setter a, b crack 10 firing furnace body 11 inlet 12 outlet 20 setter conveyor 30 substrate supply means 40 substrate receiving means C direction conversion conveyor C ₀ direction conversion conveyor C _{1 to} C ₆ conveyor

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2F065 AA02 AA06 AA12 AA15 AA20                       AA31 AA49 AA60 BB01 BB22                       CC21 DD06 FF09 FF23 FF42                       FF68 GG04 JJ05 MM03 PP15                       QQ25 QQ28 TT03 TT08                 2G051 AA42 AA90 AB03 BA10 CA20                       DA06                 4G015 EA00                 4K050 AA04 BA07 EA02 EA04                 4K056 AA12 CA10 FA11 FA23

Claims (4)

[Claims] 1. A device for detecting the breakage of a glass substrate being carried by a carrying system on the way of a carrying conveyor, wherein the breaking of the glass substrate can be measured while the glass substrate is being carried by the conveyor. A crack detection device comprising a laser displacement sensor installed at a position and signal processing means for extracting only a cracked portion of a glass substrate from the output of the laser displacement sensor. 2. An apparatus for detecting breakage of a glass substrate being conveyed by a conveying system having a direction changing conveyor for converting a conveying direction to an intersecting direction, wherein the glass substrates cross each other on the direction changing conveyor. In the state of being conveyed in the direction of, the total of three laser displacement sensors installed at the positions where the cracks of the glass substrate can be measured at two locations, respectively, and only the cracked portions of the glass substrate from the outputs of those laser displacement sensors. A crack detection device having signal processing means for extracting. 3. A sintering furnace main body for sintering a glass substrate while transporting the glass substrate on a heat-resistant setter, and a setter conveying conveyor arranged so as to connect an inlet and an outlet of the sintering furnace main body. And a substrate receiving means for transferring a glass substrate before firing onto the setter and a glass receiving means for transferring the glass substrate after firing from the setter in the middle of the setter conveyor. Alternatively, the crack detection device according to item 2 is installed between the outlet of the baking furnace main body of the setter transport conveyor and the substrate receiving means. 4. The firing line according to claim 3, wherein when a crack in the glass substrate is detected, the operation of transferring the broken glass substrate from the setter is not performed and an alarm is issued.