JP2000193598A - Foreign matter detector of transparent ingot and production of transparent body using the same - Google Patents

Abstract

[PROBLEMS] To provide a foreign body ingot detecting apparatus capable of efficiently detecting a foreign body and a method of manufacturing a transparent body using the same with high productivity. An inspection light generating means for irradiating inspection light onto a transparent body ingot Ig cut into a plurality of transparent bodies f, an imaging means for imaging the transparent body ingot Ig, and an image taken by the imaging means 3 Position of transparent body ingot Ig and transparent body ingot Ig irradiated by inspection light
A moving means 4 for moving the irradiation position of the object, an image processing means 5 for receiving a foreign substance image signal of the foreign substance m present in the transparent body ingot Ig captured by the imaging means 3 and converting the foreign substance image signal into foreign substance information; Foreign matter detection of a transparent ingot having an output means 6 for outputting foreign matter information obtained by the image processing means 5 and a control means 7 for controlling the inspection light generating means 2, the imaging means 3, the moving means 4 and the image processing means 5. apparatus.

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 foreign matter in a transparent ingot and a method for manufacturing a transparent body using the same, and particularly to a foreign matter detecting apparatus for a transparent ingot capable of efficiently detecting foreign matter and using the same. The present invention relates to a method for producing a transparent body having high productivity.

[0002]

2. Description of the Related Art Transparent quartz glass photomasks used in the manufacture of electronic devices and liquid crystals are used as masters for baking electronic circuits and the like. Is not required to be included.

Conventionally, as shown in FIG. 16, a transparent quartz glass ingot from which a photomask material is cut out has a quartz glass ingot Ig placed on a turntable 61 before cutting, so that a worker H and a fluorescent lamp 62 are separated. A quartz glass ingot Ig is placed on the surface of the quartz glass ingot Ig, and a foreign substance in the quartz glass ingot Ig is visually inspected. First, the inspection is performed from the A side, and when the inspection of the A side is completed, the turntable 61 is rotated,
Inspect the B side. Further, the inspection of the C-plane and the D-plane is performed similarly, and the inspection is completed. Based on the inspection result, the photomask material f is cut out excluding the portion of the quartz glass ingot Ig where the foreign matter exists.

[0004]

The above-described inspection of foreign matter is performed by visual inspection of the worker H. Since this visual inspection requires skill in detecting small foreign matter, there is a high possibility that small foreign matter is missed. In addition, the detection accuracy of the foreign matter varied depending on the operator H.

[0005] For this reason, as shown in FIG. 17, the portion containing the foreign matter m in the quartz glass ingot Ig is cut,
If a photomask material with a foreign substance inside is detected in the post-inspection process, this photomask material is discarded as a defective product, which means that unnecessary cutting work was performed.
This has led to a decline in productivity.

Therefore, there has been a demand for a foreign body ingot foreign matter detection apparatus capable of efficiently detecting foreign matter and a method of manufacturing a transparent body with high productivity using the same.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and provides a foreign body ingot foreign matter detecting apparatus capable of efficiently detecting foreign matter, and a method of manufacturing a transparent body using the same with high productivity. With the goal.

[0008]

According to the first aspect of the present invention, there is provided an inspection light generating means for irradiating inspection light on a transparent body ingot cut into a plurality of transparent bodies. Imaging means for imaging the transparent ingot; moving means for moving the imaging position of the transparent ingot imaged by the imaging means; and receiving a foreign object image signal of a foreign substance present in the transparent ingot imaged by the imaging means. Image processing means for converting the foreign substance image signal into foreign substance information, output means for outputting the foreign substance information obtained by the image processing means, and control for controlling the inspection light generating means, imaging means, moving means and image processing means And a foreign matter detecting device for a transparent ingot.

[0009] In the invention of claim 2 of the present application, the moving means moves an imaging position of the transparent ingot imaged by the imaging means and an irradiation position of the transparent ingot irradiated by the inspection light. The gist of the invention is a foreign matter detection device for a transparent ingot according to item 1.

In the invention of claim 3 of the present application, the gist is that the moving means is a moving device for moving the transparent ingot, and is a foreign matter detecting device for a transparent ingot according to claim 2.

[0011] The invention of claim 4 of the present application is characterized in that the moving device is a foreign object detecting device for a transparent body ingot according to claim 3, wherein the moving device is moved one-dimensionally or three-dimensionally.

5. The transparent body ingot according to claim 1, wherein said inspection light generating means is a fluorescent lamp, and said image pickup means is a CCD sensor. The gist of the invention is that it is a foreign matter detection device.

According to a sixth aspect of the present invention, the inspection light generating means is a laser light oscillating device, and the image pickup means is a CCD sensor. The gist of the invention is that the device is a foreign body detection device for a body ingot.

In the invention of claim 7 of the present application, the gist of the invention is that the CCD sensor is a two-dimensional CCD sensor, and is a foreign matter detecting device for a transparent ingot according to claim 5 or 6.

The invention according to claim 8 of the present application, wherein the inspection light generating means is a laser light oscillating device, and the imaging means is an infrared imaging device. The gist of the invention is that it is a foreign matter detection device for a transparent body ingot.

In the invention of claim 9 of the present application, the gist is that the infrared imaging device is an infrared imaging camera, and is a foreign matter detection device for a transparent ingot according to claim 8.

According to a tenth aspect of the present invention, the foreign matter information is the foreign matter position information of the transparent ingot according to any one of claims 1 to 9, wherein the foreign matter information is position information of the foreign matter. It is a gist.

In the invention of claim 11 of the present application, the foreign matter information is type information of the foreign matter, and the gist is a foreign matter detecting device for a transparent ingot according to claim 3 or 8 or 9. .

In the invention according to claim 12 of the present invention, the transparent body ingot is a quartz glass ingot, and the transparent body is a photomask material.
It is a gist of the present invention, which is a device for detecting foreign matter in a transparent ingot according to any one of the above.

According to a thirteenth aspect of the present invention, there is provided a transparent ingot to be detected, which is cut into a plurality of transparent bodies, irradiates the transparent ingot with inspection light, and moves the imaging position to the transparent ingot. The whole is imaged to image a foreign substance present in the transparent ingot, an image signal of the imaged foreign substance in the transparent ingot is received, the image signal is converted into foreign substance information, foreign substance information is output, and the output foreign substance is output. The gist of the present invention is to provide a method for manufacturing a transparent body, characterized by cutting a transparent body from a transparent body ingot so as to exclude a portion where a foreign substance is present based on information.

According to a fourteenth aspect of the present invention, the transparent body ingot is a quartz glass ingot, and the transparent body is a photomask material. It is a gist.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an apparatus for detecting a foreign substance in a transparent body ingot according to the present invention and a method of manufacturing a transparent body using the apparatus.

As shown in FIG. 1, the foreign matter detecting apparatus 1 for a transparent ingot according to the first embodiment includes a plurality of transparent bodies, for example, a transparent body ingot cut into a photomask material, for example, a quartz glass ingot Ig. Inspection light generating means for irradiating inspection light, for example, a fluorescent lamp 2, and imaging means for imaging foreign matter m such as bubbles or metal powder present in a quartz glass ingot Ig, for example, a one-dimensional CCD sensor 3, and this CCD sensor 3 The imaging position of the transparent body ingot Ig to be imaged and the transparent body ingot I irradiated by the fluorescent lamp 2
moving means for moving the irradiation position of g, for example, a lift table device 4 which is a moving device; an image processing device 5 which receives an image signal of a foreign substance from the CCD sensor 3 and uses this image signal as foreign substance information; Output means for outputting the foreign substance information obtained in step 5, for example, display 6;
And a control device 7 for controlling the power supply 2a, the CCD sensor 3 and the image processing device 5.

As shown in FIG. 2, the image processing device 5 as an image processing means has an image processing function unit 5a and a camera control function unit 5b. Implement camera control function. The image processing function unit 5a corresponds to the image processing unit of the present invention, and the camera control function unit 5b of the image processing device 5 and the control function unit 7a of the control device 7 correspond to the control unit of the present invention. The output unit 6 may be directly connected to the image processing device 5 or may be connected to the image processing device 5 via the control device 7 if the foreign object information obtained by the image processing device 5 is output.

The camera control function may be provided in the control device 7. Further, the image processing device 5 and the control device 7 may be integrally configured as a unit.

The fluorescent lamp 2 is normally used for a CCD sensor, and irradiates a quartz glass ingot Ig mounted on a lift table device 4 with inspection light. This is for capturing an image of the quartz glass ingot Ig, and has a range where the image capturing field of view is larger than the width of the quartz glass ingot Ig.

The fluorescent lamp 2 and the CCD sensor 3 are arranged so as to sandwich the lift table device 4 between the fluorescent lamp 2 and the CCD sensor 3 and are arranged on the same optical axis.
The region irradiated with the quartz glass ingot Ig by C
The CD sensor 3 captures an image.

The lift table device 4 includes an irradiation position of the inspection light to the quartz glass ingot Ig and a CCD.
A lift table main body 4a on which a quartz glass ingot Ig is mounted, a servo motor 4b for raising and lowering the lift table main body 4a, and a lift for moving an imaging position of the sensor 3 in a vertical direction (Z-axis direction). It comprises a position detecting device for detecting the vertical position of the table body 4a, for example, a linear scale 4c.
The linear scale 4c is provided on one side of the lift table body 4a so that the fluorescent lamp 2 does not hinder the irradiation of the quartz glass ingot Ig.

The control device 7 controls the image processing device 5 and the fluorescent lamp 2, and further controls the servomotor 4b based on the position information from the linear scale 4c to control the elevation of the lift table body 4a.

Next, a cutting apparatus used in a method of manufacturing a transparent body from a transparent body ingot inspected by using the transparent body ingot foreign matter detecting apparatus according to the present invention will be described.

As shown in FIG. 3, the transparent body ingot cutting device 11 includes a cutting blade portion having a driving device (not shown), for example, a band saw 12, and a device base 13 provided opposite to the band saw 12. It has a mount 14 for the quartz glass ingot Ig movably provided above, and a feeder 15 for feeding the mount 14 in the horizontal linear direction (X-axis). The feed device 15 is rotatably provided on the device base 13, and a screw shaft 15 a screwed through a screw portion (not shown) provided on the bottom surface of the device base 13.
And a servo motor 15b for rotating the screw shaft 15a, and a cutting device control means 16 for controlling the servo motor 15b and the band saw 12.

Therefore, in the cutting device 11, the quartz glass ingot I attached to the mounting base 14 via the mounting plate 17 is provided.
g by the command of the cutting device control means 16
5b, the screw shaft 15a can be operated to move to a predetermined position. Further, a display 6 connected to the image processing device 5 of the foreign matter detection device 1 described above is arranged near the cutting device control means 16.

Next, an apparatus for detecting foreign matter in a transparent ingot according to the first embodiment and a method for manufacturing a transparent body using the same will be described.

In the pre-process, the quartz glass ingot Ig heated in an electric furnace and molded by a molding machine and then polished to form a rectangular parallelepiped is free from foreign matter such as bubbles and metal powder. It is inspected by the foreign object detection device 1 for existence.

First, the cut surface p of the quartz glass ingot Ig is placed horizontally (the lift table body 4a) on the lift table body 4a where the quartz glass ingot Ig is positioned at the lowest position.
(Parallel to the vertical axis) and placed vertically. Next, the fluorescent lamp 2 is turned on via the power supply 2a in accordance with a command from the control device 7 to irradiate the lowest portion of the quartz glass ingot Ig. On the other hand, the CCD sensor 3 via the image processing device 5 at the command of the control device 7 causes the lowermost portion of the quartz glass ingot Ig irradiated with the fluorescent lamp 2, for example, the first photomask material f to be cut. Site f1 corresponding to
Start imaging from the lower end f1e. Further, the lift table main body 4a is continuously raised by a command from the control device 7, and the rectangular parallelepiped quartz glass ingot Ig is continuously imaged by the CCD sensor 3.

For example, the image processing device 5 and the control device 7
Is calculated in accordance with the program, and 1 of the photomask material f
If the foreign substance information is output for every thickness equivalent to a sheet, the image signal of the imaged region f1 is processed by the image processing device 5 and output, and is stored in the storage unit of the image processing device 5. Display 6 and control device 7
Is output to In this step, if there is no foreign matter in the portion f1 corresponding to the first sheet, the display 6 does not display anything.

On the other hand, the lift amount of the lift table body 4a which is raised by the servo motor 4b is the linear scale 4c.
And is stored in the control device 7 as position information of the quartz glass ingot Ig.

Further, a portion f2 corresponding to the second sheet irradiated on the fluorescent lamp 2 by the CCD sensor is imaged, and an image signal of the imaged portion f2 is image-processed by the image processing device 5 and output in the same manner as described above. Are stored in the storage unit of the image processing device 5 and output to the display 6 and the control device 7. In this step, the portion f2 corresponding to the second sheet
If there is a foreign matter m2 in the image processing apparatus 5 as shown in FIG.
And the size of the foreign matter m2 is stored in the storage unit. Further, the same process as described above is repeated, and an image of the portion f3 corresponding to the third sheet is taken. In this step, when the foreign matter m3 exists in the portion f3 corresponding to the third sheet,
As shown in FIG. 4B, the size of the foreign substance m3 is output from the image processing apparatus 5 to the display 6 as foreign substance information and stored in the storage unit.

In the same manner as described above, imaging is performed up to the portion fn corresponding to the n-th sheet, and the detection of foreign matter in the quartz glass ingot Ig is completed.

The detected foreign matter m can be displayed as shown in FIG. 4C on the three-dimensional view of the quartz glass ingot Ig.

As described above, in the present embodiment, the CCD sensor for imaging the quartz glass ingot Ig in a planar manner, and the feeding device 15 for moving the imaging position of the quartz glass ingot Ig in a direction perpendicular (perpendicular) to the imaging surface. With this function, foreign substances can be detected over the entire surface of the rectangular parallelepiped quartz glass ingot Ig, so that the foreign substances can be reliably detected.

Next, a method of manufacturing a photomask material using the quartz glass ingot Ig inspected by the transparent ingot foreign substance detecting device 1 of the first embodiment will be described.

The quartz glass ingot Ig for which foreign object detection has been completed is transferred from the lift table main body 4a to the mounting plate 17 provided on the upper surface of the mounting table 14 of the cutting device 11, and fixed to the mounting plate 17 with an adhesive.

FIG. 4 shows the foreign matter detection status of the quartz glass ingot Ig inspected by the foreign matter detecting device 1 described above.
(A) and / or the display 6 arranged near the cutting device control means 16 in the state shown in FIG.
Will be displayed. For example, since no foreign matter exists in the portion f1 corresponding to the first sheet, the cutting device control means 16 is controlled to drive the servo motor 15b and rotate the screw shaft 15a. By the rotation of the screw shaft 15a, the mount 14 is fed by a predetermined amount, for example, by the thickness of the photomask material. Thereafter, the band saw 12 is operated to cut the quartz glass ingot Ig to the thickness of the photomask material. Next, a portion f1 corresponding to the second and third sheets
Since there are foreign substances m2 and m3 in the table, cutting between the second sheet f2 and the third sheet f3 is not performed, but cutting between the third sheet f3 and the fourth sheet f where no foreign matter is present. Thereafter, cutting is performed in the same manner to obtain a photomask material f from the quartz glass ingot Ig.

In this cutting step, as in the prior art, the detection of the foreign matter is insufficient and the presence of the foreign matter is overlooked, and the foreign matter m2,
The second sheet f2 and the third sheet f which should be defective due to the presence of m3
3 also cuts off the portion containing no foreign matter in the same way, and discards the second sheet f2 and the third sheet f3 as defective after cutting, unlike the second sheet f2 and the third sheet Since the cutting of the eye f3 is not performed, the waste of the cutting operation can be eliminated, and the productivity of the photomask material can be increased.

In the first embodiment, the position of the foreign matter m is displayed by using the display 6 as the output means, and the portion f where the foreign matter m is present is not cut. It is also possible to use a printer to print out the portion f where the foreign matter m is present on paper and not to cut the portion f where the foreign material m is present.

Further, as shown in FIG.
Is connected to the cutting device control means 16, and the position information of the foreign matter m stored in the storage section of the image processing device 5 is taken out to the control device 7 and sent to the cutting device control means 16 to detect the foreign matter m. If the cutting position of the band saw 12 is controlled so as to avoid the foreign matter m and minimize the waste material, the cutting position of the band saw 12 can be automatically set without the intervention of an operator, which is efficient and efficient. is there.

Next, a foreign substance detecting device for a transparent body ingot according to a second embodiment will be described.

The same parts as those of the foreign matter detecting device 1 for a transparent body ingot according to the first embodiment will be described with the same reference numerals.

As shown in FIG. 6, a foreign object detecting device 21 for a transparent body ingot according to the second embodiment includes a fluorescent lamp 2 for irradiating inspection light onto a quartz glass ingot Ig, and a two-dimensional CCD.
A sensor 22; a moving unit 23 for moving an imaging position of the quartz glass ingot Ig captured by the CCD sensor 22 and an irradiation position of the quartz glass ingot Ig irradiated by the fluorescent lamp 2; the image processing device 5; It has a display 6 for outputting foreign matter information obtained by the processing device 5, and a control device 7 for controlling the fluorescent lamp 2, the CCD sensor 22 and the image processing device 5.

The moving means 23 is formed so that a table 23a on which the quartz glass ingot Ig is mounted can be moved three-dimensionally, and an X-axis table 23b on which the table 23a is slidably mounted, and a table 23a. A screw shaft 23c for moving the screw shaft 23a in the horizontal X direction, and a servo motor 23d for rotating the screw shaft 23c
And the Y-axis table 2 on which the X-axis table 23b is slidably mounted.
The table 23a is moved in the Y-axis direction by using a screw shaft (not shown) for moving the screw 3e in the horizontal Y-axis direction and a servomotor (not shown) for rotating the screw shaft. A Z-axis table 23f on which a Y-axis table 23e on which the 23b is placed is mounted so as to be movable in the vertical Z-axis direction;
Screw shaft 23 rotatably mounted on 3f
g, and a servomotor (not shown) for rotating the screw shaft 23g to move the table 23a in the Z-axis direction.

Next, the quartz glass ingot I using the quartz glass ingot foreign matter detecting device 21 of the second embodiment is used.
A method for detecting g will be described.

First, the quartz glass ingot Ig is placed on the table 23a located at the rearmost position and the lowest position. Next, the focal point of the CCD sensor 22 and the irradiation position of the fluorescent lamp 2 are divided into cells each of which is assumed to be a plurality of small rectangular parallelepiped quartz glass ingots Ig, for example, one of the first imaging layers.
It is adjusted to the imaging part p (1, 3, 1) in the third row and the third column. This cell is assumed to be calculated by the image processing device 5 and the control device 7 according to a program.

The servo motor is operated by the control device 7 to rotate the screw shaft, and the X-axis table 23b
At the same time, the table 23a is retracted, and the imaging site p (1,..., 1st row, 1st column of the first imaging layer of the quartz glass ingot Ig
The center part of (1) and (1) is positioned at the focal point of the CCD sensor 22. Note that the CCD sensor 22 has a depth of focus, and the entire imaging region p (1, 1, 1) is clearly imaged by focusing on the center of the imaging region p (1, 1, 1). Thereafter, the control device 7 controls the CCD sensor 22 and the CCD sensor 22 controls the imaging part p (1, 1, 1).
Is imaged.

The image signal of the imaged region p (1,1,1) is output after being subjected to image processing by the image processing device 5, and is stored in the storage unit of the image processing device 5 and transmitted to the display 6 and the control device 7. Is output. In this step, if there is no foreign matter in the imaging part p (1, 1, 1), no display is displayed on the display 6, while the control device 7 outputs the servo motor based on the output from the image processing device 5. 23
By driving d, the screw shaft 23c is rotated, the table 23a is moved in the X-axis direction, and the imaging sensor p (2, 1, 1) is focused on the CCD sensor 22, and the imaging sensor p (1,. The imaging part p (2, 1, 1) is imaged in the same manner as the imaging of (1, 1), and the image signal of the imaged imaging part p (2, 1, 1) is subjected to image processing by the image processing device 5. The output is stored in the storage unit of the image processing device 5 and output to the display 6 and the control device 7. In this step, when the foreign matter m is present in the imaging portion p (2, 1, 1), the foreign matter information is output from the image processing device 5 to the display 6 as foreign matter information, and the location and size of the foreign matter m are stored in the storage unit. Is stored.

Further, the same steps as described above are repeated, and when the imaging of the imaging site p (n, 1, 1) is completed, the servo motor is operated by the control device 7 to rotate the screw shaft, and the table is moved together with the X-axis table 23b. 23a to Y
The central portion of the imaging region p (1, 2, 1) in the first row and second column of the first imaging layer of the quartz glass ingot Ig is positioned at the focal point of the CCD sensor 22 in the axial direction. Thereafter, the same imaging process as described above is performed, and when the imaging is performed up to the imaging site p (n, n, n), the foreign object detection is completed.

The quartz glass ingot Ig for which the foreign substance detection has been completed utilizes the foreign substance information output to the output means in the same manner as in the first embodiment, and eliminates the waste of the cutting process from the quartz glass ingot Ig to the photomask. Cut out.

In the foreign substance detecting device 21 according to the second embodiment, a quartz glass ingot Ig imaging region p (1,1,.
1) to p (n, n, n), since the image is divided and imaged, the foreign substance m can be imaged more clearly, and the foreign substance can be easily found.

Next, a foreign substance detecting device for a transparent ingot according to a third embodiment will be described.

The same parts as those of the foreign matter detecting device 1 of the transparent body ingot of the first and second embodiments will be described with the same reference numerals.

As shown in FIG. 7, a foreign substance detecting device 31 for a transparent body ingot according to the third embodiment includes an inspection light generating device for irradiating a quartz glass ingot Ig with inspection light, for example, a laser light oscillation device 32, A three-dimensional CCD sensor 33, a moving means 34 for moving an imaging position of the quartz glass ingot Ig imaged by the CCD sensor 33 and an irradiation position of the quartz glass ingot Ig irradiated by the laser beam, the image processing device 5, It has a display 6 for outputting foreign substance information from the image processing device 5, and a control device 7 for controlling the laser light oscillation device 32, the CCD sensor 33 and the image processing device 5.

The moving means 34 includes a table 34a on which the quartz glass ingot Ig is slidably mounted, a pressing plate 34b for moving the quartz glass ingot Ig on the table 34a in the horizontal X-axis direction, and a pressing plate 34b. It has a screw shaft 34e that presses 34b via a connector 34c and a threaded portion 34d, and a servo motor 34f that rotates the screw shaft 34e.

The table 34a has a through hole 34g for imaging on the optical axis of the laser beam oscillator 32 and the CCD sensor 33.
Are drilled.

Next, the quartz glass ingot I using the quartz glass ingot foreign matter detecting device 31 of the third embodiment is described.
A method for detecting g will be described.

First, the pressing plate 3 waiting at the rearmost position
4b, the quartz glass ingot Ig is placed on the table 34a with its longitudinal direction horizontal. Next, the servo motor 34f is driven by a command from the control device 7 to rotate the screw shaft 34e, and the quartz glass ingot Ig is pressed by the pressing plate 34b via the screwing portion 34d and the connector 34c, and the quartz glass ingot Ig is removed. It is located at the forefront part, for example, a part h1 corresponding to the first sheet of the photomask material h to be cut. Thereafter, the control device 7 operates the laser light oscillation device 32 to oscillate the laser light L, and the CCD sensor 33 starts imaging the part h1. At the start of imaging, the servo motor 34f is driven by a command from the control device 7 to
e, the quartz glass ingot Ig is moved at a predetermined speed by the pressing plate 34b on the table 34a, and a portion h passing through the imaging through hole 34g is irradiated with the laser light L to be imaged by the CCD sensor 33. . In the imaging process by the CCD sensor 33, the image signal from the CCD sensor 33 is subjected to image processing by the image processing device 5 and output, and is stored in the storage unit of the image processing device 5 and output to the display 6 and the control device 7. You. FIG. 8 shows an image-processed output. When foreign matter m such as foam or metal powder is present, the output level is increased, and it is possible to clearly grasp at which part h of the quartz glass ingot Ig the foreign matter m is present. .

Therefore, the photomask f is cut out from the quartz glass ingot Ig without wasting the cutting process by utilizing the foreign matter information as in the first and second embodiments.

In the third embodiment, since the laser beam L is irradiated while moving the quartz glass ingot Ig to capture an image, it is possible to detect foreign substances quickly.

Next, a foreign substance detecting device for a transparent body ingot according to a fourth embodiment will be described.

The same parts as those of the foreign object detecting device 1 of the transparent body ingot of the first to third embodiments are denoted by the same reference numerals and described.

As shown in FIG. 9, a foreign substance detecting device 41 for a transparent ingot according to the fourth embodiment comprises a laser light oscillating device 32 for irradiating a quartz glass ingot Ig with a laser beam.
And an infrared imaging device, for example, an infrared imaging camera 42,
A moving unit 43 for moving an imaging position of the quartz glass ingot Ig imaged by the infrared imaging camera 42 and an irradiation position of the quartz glass ingot Ig irradiated by the laser light, the image processing device 5, and the image processing device 5. And a control device 7 for controlling the laser light oscillation device 32, the infrared imaging camera 42, and the image processing device 5.

The moving means 43 includes an X-axis table 43b on which a table 43a on which a quartz glass ingot Ig is fixed is slidably mounted, a screw shaft 43c for moving the table 43a in the horizontal X direction, and a screw shaft 43c. And a servo motor 43d for rotating 43c.

Next, the quartz glass ingot I using the quartz glass ingot foreign matter detecting device 41 of the fourth embodiment is described.
A method for detecting a foreign substance of g will be described.

First, the quartz glass ingot Ig is placed on the table 43a waiting at the last retreat position (the front side in FIG. 9). Next, the servo motor 4 is controlled by a command from the controller 7.
By driving the screw shaft 43c by driving 3d, the quartz glass ingot Ig is moved, and the infrared imaging camera 42 is moved to the foremost part of the quartz glass ingot Ig, for example, the part i1 corresponding to the first piece of the photomask material to be cut. And the irradiation position of the laser beam L are adjusted.
Thereafter, the control device 7 activates the laser light oscillation device 32 to oscillate the laser light L, and the infrared imaging camera 42 starts imaging the part i1. At the start of imaging, the servo motor 43d is driven by the instruction of the control device 7 to rotate the screw shaft 43c, and the quartz glass ingot Ig placed on the table 43a is moved at a predetermined speed and irradiated with the laser light L. Then, the infrared imaging camera 42 takes an image of the entire quartz glass ingot Ig. In the imaging process by the infrared imaging camera 42, the image signal from the infrared imaging camera 42 is subjected to image processing by the image processing device 5 and output, stored in the storage unit of the image processing device 5, and transmitted to the display 6 and the control device 7. Is output.

FIG. 10 shows an output image subjected to image processing, showing a state in which no foreign matter such as bubbles or metal powder is present. FIG. 11 shows an output image in the case where foreign matter m is present. m is heated by the laser light L, so that the center of the foreign matter m is darkest and the color is radially light. FIG. 12 shows an output image of the optical image capture.

Therefore, the photomask is cut out from the quartz glass ingot Ig without waste of the cutting step by utilizing the foreign matter information as in the first to third embodiments described above.

In the fourth embodiment, since the heat distribution of the foreign matter m also affects the periphery of the foreign matter m, the image is displayed as an image larger than the size of the foreign matter m. It is easier to find the foreign matter m than the optical image recognition as shown in FIG.

Next, an apparatus for detecting foreign matter in a transparent ingot according to a fifth embodiment will be described.

The same parts as those of the foreign object detecting device 1 of the transparent ingot of the second and fourth embodiments are denoted by the same reference numerals and described.

As shown in FIG. 13, a foreign substance detecting device 51 for a quartz glass ingot according to the fifth embodiment includes a laser light oscillating device 32 for irradiating a laser beam L to a quartz glass ingot Ig, and an infrared imaging device, for example, an infrared ray Imaging camera 4
2, moving means 23 for moving the imaging position of the quartz glass ingot Ig imaged by the infrared imaging camera 42 and the irradiation position of the quartz glass ingot Ig irradiated by the laser light L, the image processing device 5, and the image Display 6 for outputting foreign matter information from processing device 5
And a control device 7 for controlling the laser light oscillation device 32, the infrared imaging camera 42, and the image processing device 5.

The moving means 23 has the same structure as the moving means of the second embodiment as shown in FIG. 6, and includes a table 23a, an X-axis table 23b, a screw shaft 23c, a servomotor 23d, , Y-axis table 23e
, Screw shaft 23h, servo motor 23i
, Z-axis table 23f, and screw shaft 23g
And a servo motor (not shown).
3a can be moved three-dimensionally.

Next, the quartz glass ingot I using the quartz glass ingot foreign matter detecting device 51 of the fifth embodiment will be described.
A method for detecting g will be described.

As shown in FIG. 13, the quartz glass ingot Ig is first placed on the table 23a located at the rearmost position on the X-axis, the intermediate position on the Y-axis, and the lowest position on the Z-axis. Next, the focal point of the infrared imaging camera 42 and the irradiation position of the laser beam L are set at the uppermost position, the center, and the position of the portion f1 corresponding to the first sheet of the photomask material of the quartz glass ingot Ig.
For example, it is adjusted to the imaging part j (1, k, 1). The control device 7 operates the servo motor to rotate the screw shaft, and the X-axis table 23b and the table 23 are rotated.
a is retracted in the Y-axis direction, and the imaging region j (1, 1, 1) in the first row and first column of the first imaging layer of the quartz glass ingot Ig.
The focus of the infrared imaging camera 42 is adjusted to the center of the camera.

Thereafter, the control device 7 controls the infrared imaging camera 42, and the infrared imaging camera 42 images the imaging site j (1, 1, 1). Imaged part j imaged
The (1, 1, 1) image signal is subjected to image processing by the image processing device 5 and output, and is stored in the storage unit of the image processing device 5 and output to the display 6 and the control device 7.
In this step, if there is no foreign matter in the imaging part j (1, 1, 1), the display 6 does not display any information, while the control device 7 outputs the servo motor 23i based on the output from the image processing device 5. Is driven to rotate the screw shaft 23h to move the table 23a to Y.
The imaging part j (1, 1, 1) is moved in the axial direction, and the infrared imaging camera 42 is focused on the imaging part j (1, 2, 1).
The imaging part j (1, 2, 1) is imaged similarly to the imaging of 1), and the image signal of the imaged imaging part j (1, 2, 1) is subjected to image processing by the image processing device 5 and output. Are stored in the storage unit of the image processing device 5 and output to the display 6 and the control device 7. In this step, when the foreign matter m exists in the imaging part j (1, 2, 1), the position, size, quantity, and material of the foreign matter m are output from the image processing device 5 to the display 6 as foreign matter information. Is displayed and the foreign substance information is also stored in the storage unit.

The location of the foreign matter m is displayed as an imaging part j (k, k, k) determined from the feed amount of the moving means 23, and the size of the foreign matter m is determined by the infrared imaging camera 42 and the imaging part j (k, k). , K) is calculated from the distance and the ratio between the cell and the number of pixels of the foreign matter, the quantity of the foreign matter m is determined by counting the number of which the size is calculated, and the material is the specific heat of the material determined by the heat distribution. And the specific heat of the material previously obtained and stored.

As shown in FIG. 14, the same steps as described above are repeated, and when the imaging of the imaging site j (1, n, n) is completed, the controller 7 operates the servomotor 23d to drive the screw shaft 23c. While rotating, the table 23a is advanced in the X-axis direction together with the X-axis table 23b while maintaining the positions in the Y-axis and Z-axis directions, and the imaging part corresponding to the second piece of the photomask material of the quartz glass ingot Ig The center of j (2, n, n) is located at the infrared imaging camera 42.
Focus on. The image of each cell is taken in the reverse order with respect to the above-described portion of X = 1 (the portion corresponding to the first photomask material). Complete.

In the foreign substance detection device 51 of the fifth embodiment, the position, size, quantity and material of the foreign substance m can be displayed as shown in FIG. Further, the detected foreign matter m can be displayed as shown in FIG. 4C on the three-dimensional view of the quartz glass ingot Ig.

Further, as a display method other than the display of the foreign material name, the color of the cell is displayed according to the amount of the foreign material, the size of the foreign material, and the material of the foreign material, so that the foreign material in the quartz glass ingot Ig can be more easily displayed. The existence position, the existence amount, and the material can be determined, and the photomask material can be cut out with high productivity while avoiding the foreign matter m in the quartz glass ingot Ig.

[0088]

As described above, according to the apparatus for detecting foreign matter in a transparent ingot according to the present invention, foreign matter present in the transparent ingot can be reliably detected.

Further, according to the method for manufacturing a transparent body according to the present invention, the transparent body can be cut out from the transparent body ingot with high productivity without waste.

If the image pickup position and the irradiation position are moved by the moving means, foreign matters in the rectangular parallelepiped transparent ingot can be easily detected.

If the moving means is a mounting table that moves one-dimensionally or three-dimensionally, foreign substances in a rectangular parallelepiped transparent ingot can be easily detected even by using a one-dimensional imaging device.

If a fluorescent lamp is used for the inspection light generating means and a CCD sensor is used for the image pickup means, the transparent foreign matter can be detected reliably and efficiently.

If a laser beam is used for the inspection light generating means and a CCD sensor is used for the image pickup means, it is possible to reliably and efficiently detect the foreign matter on the transparent body.

If a two-dimensional CCD sensor is used as the CCD sensor, foreign matter in a rectangular parallelepiped transparent ingot can be detected easily and reliably even if the moving device for the transparent body is simplified.

If laser light is used for the inspection light generating means and an infrared imaging device is used for the imaging means, not only the position and size of the foreign matter but also the material of the foreign matter can be known.

If an infrared imaging camera is used as the infrared imaging device, the position of foreign matter,
Not only the size but also the material of the foreign matter can be known.

If the foreign substance information is the positional information of the foreign substance, the transparent body can be cut out while avoiding the part where the foreign substance exists, and the productivity of the transparent body production can be improved.

Although the foreign substance information is the type information of the foreign substance, the transparent body can be cut out while avoiding the part where the foreign substance is present, and it is convenient to find the step of mixing the foreign substance.

In the case where the transparent body ingot is a quartz glass ingot and the transparent body is a photomask material, it is possible to increase the productivity of the production of a photomask material in which the presence of particularly fine foreign substances is not allowed.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a first embodiment of a foreign matter detecting device for a transparent ingot according to the present invention.

FIG. 2 is an explanatory diagram of an image processing / control device used in the first embodiment of the foreign object detecting device for a transparent ingot according to the present invention.

FIG. 3 is an explanatory view of a cutting device used in the method of manufacturing a transparent body according to the present invention.

FIG. 4 is an explanatory diagram illustrating a display state of a foreign object output to an output device.

FIG. 5 is an explanatory view of a foreign matter detecting device and a cutting device for a transparent body ingot according to the present invention.

FIG. 6 is an explanatory view of a second embodiment of the foreign object detecting device for a transparent ingot according to the present invention.

FIG. 7 is an explanatory view of a third embodiment of the foreign matter detecting device for a transparent ingot according to the present invention.

FIG. 8 is an explanatory diagram showing a portion of a foreign object detected by a third embodiment of the foreign object detection device for a transparent ingot according to the present invention.

FIG. 9 is an explanatory diagram of a fourth embodiment of the foreign matter detecting device for a transparent ingot according to the present invention.

FIG. 10 is an output diagram according to a fourth embodiment of the apparatus for detecting foreign matter in a transparent ingot according to the present invention.

FIG. 11 is an output diagram of foreign matter detected by a foreign matter detecting device for a transparent ingot according to a fourth embodiment of the present invention.

FIG. 12 is an output diagram of foreign matters in a transparent ingot by an optical system.

FIG. 13 is an explanatory view of a fifth embodiment of the foreign matter detecting device for a transparent ingot according to the present invention.

FIG. 14 is an explanatory diagram showing an imaging order of a fifth embodiment of the foreign object detecting device for a transparent ingot according to the present invention.

FIG. 15 is an explanatory view showing a state of foreign matter detected by a fifth embodiment of the foreign matter detecting apparatus for a transparent ingot according to the present invention.

FIG. 16 is an explanatory diagram of a conventional foreign matter detection method.

FIG. 17 is an explanatory view showing a state in which a photomask material is cut out from a quartz glass ingot.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Foreign substance detection device of transparent ingot 2 Fluorescent lamp 3 One-dimensional CCD sensor 4 Lift table device 4a Lift table main body 4b Servo motor 4c Linear scale 5 Image processing device 6 Display 7 Control device Ig Quartz glass ingot 11 Transparent device ingot cutting device DESCRIPTION OF SYMBOLS 12 Band saw 13 Device base 14 Mounting stand 15a Feeding device screw shaft 15b Servo motor 16 Cutting device control means 17 Mounting plate

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[Procedure amendment]

[Submission date] July 7, 1999 (July 7, 1999)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

FIG. 5

Continuing on the front page (72) Inventor Yasunori Kanamori 30 Soya, Hadano-shi, Kanagawa Prefecture, Toshiba Ceramics Co., Ltd. (72) Inventor Keisuke Yamazaki 30 Soya, Hadano-shi, Kanagawa Toshiba Ceramics Co., Ltd. ) Inventor Hironobu Nakazawa 30 Soya, Hadano-shi, Kanagawa F-term in the development laboratory of Toshiba Ceramics Co., Ltd. (reference) 2G051 AA56 AA61 AB06 AC04 BA10 CB02 DA07 EA12 3C069 AA01 CA04 CB05 EA01

Claims (14)

[Claims] 1. An inspection light generating means for irradiating inspection light to a transparent body ingot cut into a plurality of transparent bodies, an imaging means for imaging the transparent body ingot, and a transparent body ingot imaged by the imaging means. Moving means for moving the imaging position, image processing means for receiving a foreign object image signal of a foreign substance present in the transparent body ingot imaged by the imaging means, and converting the foreign object image signal into foreign substance information; And a control unit for controlling the inspection light generating unit, the image pickup unit, the moving unit, and the image processing unit. 2. The transparent body ingot according to claim 1, wherein the moving means moves an imaging position of the transparent body ingot imaged by the imaging means and an irradiation position of the transparent body ingot irradiated by the inspection light. Foreign matter detection device. 3. The apparatus for detecting foreign matter in a transparent ingot according to claim 2, wherein said moving means is a moving device for moving the transparent ingot. 4. The apparatus for detecting foreign matter in a transparent ingot according to claim 3, wherein the moving device is moved one-dimensionally or three-dimensionally. 5. The apparatus according to claim 1, wherein the inspection light generating means is a fluorescent lamp, and the imaging means is a CCD sensor.
5. The foreign matter detection device for a transparent body ingot according to any one of items 4 to 4. 6. The apparatus for detecting foreign matter in a transparent ingot according to claim 1, wherein said inspection light generating means is a laser light oscillating device, and said imaging means is a CCD sensor. . 7. The apparatus for detecting foreign matter in a transparent ingot according to claim 5, wherein the CCD sensor is a two-dimensional CCD sensor. 8. The foreign matter detection of a transparent body ingot according to claim 1, wherein said inspection light generation means is a laser light oscillation device, and said imaging means is an infrared imaging device. apparatus. 9. The apparatus according to claim 8, wherein the infrared imaging device is an infrared imaging camera. 10. The apparatus for detecting foreign matter in a transparent ingot according to claim 1, wherein the foreign matter information is position information of a foreign matter. 11. The foreign matter detecting device for a transparent ingot according to claim 3, wherein the foreign matter information is type information of the foreign matter. 12. The apparatus for detecting foreign matter in a transparent ingot according to claim 1, wherein the transparent ingot is a quartz glass ingot, and the transparent body is a photomask material. 13. A transparent body ingot to be detected, which is cut into a plurality of transparent bodies, is prepared, an inspection light is irradiated on the transparent body ingot, and the entire transparent body ingot is imaged while moving the imaging position to obtain a transparent body. A foreign object present in the body ingot is imaged, an image signal of the imaged foreign object in the transparent body ingot is received, the image signal is converted into foreign object information, foreign object information is output, and a foreign object is detected based on the output foreign object information. A method for manufacturing a transparent body, comprising cutting a transparent body from a transparent body ingot so as to exclude a part to be transparentized. 14. The method for manufacturing a transparent body according to claim 13, wherein the transparent body ingot is a quartz glass ingot, and the transparent body is a photomask material.