JP2002039953A - Glass substrate for storage medium and method and apparatus for detecting defect of glass vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a defect in a glass or on the surface thereof stably with high accuracy regardless of dust on the glass surface without requiring a clean room. SOLUTION: Light is projected to the outer circumferential side face of a glass substrate or the end face at the mouth of a glass vessel and a component of the light diffuse reflected at a defect in the glass substrate or on the surface thereof and outgoing therefrom is detected thus detecting a defect of the glass substrate. Light can impinge on the outer circumferential side face or the end face at the mouth without striking the glass surface when a holder matching the shape of the glass substrate or the glass vessel under inspection is employed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass substrate for a storage medium and bubbles, foreign matters, and shear marks (a series of bubbles generated when glass is cut) in a glass container such as a glass bottle and a glass tableware. ), A method and an apparatus for detecting defects such as scratches on the glass surface.

[0002]

2. Description of the Related Art A glass substrate for a storage medium is visually inspected in a clean room. In other words, this method is a method of selecting defective products when the surface of the glass substrate is illuminated by light.

In containers such as bottles and tableware, the amount of transmitted light is checked by irradiating the glass surface with light, and where there is a defect, the light is blocked or scattered to reduce the amount of transmitted light. There is a method of examining the amount of reflected light, and detecting the reflected light amount where there is a defect, because the amount of reflected light at that portion increases.

[0004]

According to the above-mentioned conventional method for detecting a glass substrate for a recording medium, if any dust, dirt or dirt adheres to the surface of the glass substrate, the portion shines. It is indispensable to remove the dust, dirt and dirt on the surface of the surface, and a clean room is required. In addition, when light is applied to the glass, the detection accuracy changes depending on the angle at which the light is applied, so that the method of applying the light must be adjusted by trial and error. Furthermore, since the detection accuracy changes depending on the individual difference of the inspector, there is a problem that stable inspection cannot be performed.

In the above-described conventional method for inspecting a glass container, dust, dirt, dirt, and the like adhering to the glass surface cause noise, so that it is actually very difficult to detect a defect having a size of 0.2 mm or less. There's a problem.

An object of the present invention is to make it possible to detect a defect inside or on the surface of glass with high accuracy in a stable manner without being affected by dust and dirt on the glass surface and without requiring a clean room. .

[0007]

According to the present invention, light is incident on the outer peripheral side surface of a glass substrate, and the light is irregularly reflected by a defect inside or on the surface of the glass substrate, and the light exits from the surface of the glass substrate. This is a method for detecting a defect of a glass substrate for a storage medium, wherein a defect of the glass substrate is detected by detecting incoming light.

According to another aspect of the present invention, there is provided a storage device comprising: a light source; and a holder which wraps the outer peripheral side surface of the glass substrate and prevents light from the light source from being irradiated to the outer peripheral side surface of the glass substrate. This is a device for detecting a defect of a glass substrate for a medium.

As shown in FIG. 4, light is not applied to the surface of the glass substrate 2 but from the side (from the outer peripheral side surface 2a) so as not to impinge on the surface of the glass substrate via the holder 4.
Inject into glass. If the length of the holder 4 is set to an appropriate length or more, a light projector or the like can be used as a light source without using a strict parallel light source of a type in which a laser sheet light source or a concave mirror is placed behind. The light that has entered the glass travels through the glass toward the opposite outer peripheral surface while being totally reflected at the glass interface, as indicated by the arrows.
If the glass has a defect 11 (bubble, foreign matter, shear mark, etc.), the light diffusely reflects and comes out of the glass from the surface of the glass substrate. Since no light is applied to the glass surface, light that emerges from the surface due to irregular reflection due to defects can be clearly detected. Therefore, stable detection is possible without overlooking a small defect. The position and size of the shear mark can also be clearly recognized. In addition, since the surface is not exposed to light, a certain amount of dust and dirt may adhere to the surface, and a clean room is not required.

In order to prevent the light from the light source from being radiated to a portion other than the outer peripheral side surface of the glass substrate, the outer peripheral portion of the glass substrate is mounted on a holder that wraps around half of the entire outer peripheral side surface of the glass substrate. Good. It is convenient to form the holder into a cylindrical shape and allow light from a light source to pass therethrough. If packing such as rubber is used for a portion of the holder that contacts the glass substrate, the packing is in close contact with the glass and light does not leak from the gap.

In the case of detecting light that is diffusely reflected due to a defect and emerges from the front or rear surface of the glass, automatic detection becomes possible by using a detecting means such as a CCD camera.

Further, according to the present invention, light is incident on the end face of the mouth of the glass container, and the light is diffusely reflected by a defect inside or on the surface of the glass of the glass container and emerges from the glass surface of the glass container. This is a method for detecting a defect of a glass container, wherein the defect of the glass container is detected by detecting light.

Further, the present invention provides a glass having a light source and a holder which wraps around the mouth of the glass container and prevents light from the light source from being emitted to an area other than the end of the mouth of the glass container. It is a device for detecting a defect of a container.

When the light is incident on the glass from the upper end surface of the mouth so that the light does not impinge on the surface of the glass container via the holder, instead of irradiating the light on the surface of the glass container, the light is emitted similarly to the case of the glass substrate. Travels through the glass while undergoing total reflection at the glass interface. If there is a defect in the glass, the light diffusely reflects out of the glass surface and out of the glass. Since no light is applied to the glass surface, light that emerges from the surface due to irregular reflection due to defects can be clearly detected. Therefore, stable detection is possible without overlooking a small defect. Further, since no light is applied to the glass surface, some dust and dust may adhere to the glass surface.

In order to prevent the light from the light source from being emitted to the area other than the end face of the glass container, it is necessary to mount the glass container so as to enclose the glass container opening in a holder conforming to the shape of the opening of the glass container. Good. If packing such as rubber is used for a portion of the holder that contacts the glass container, the packing is in close contact with the glass and light does not leak from the gap.

When detecting light that is diffusely reflected due to a defect and emerges from the surface of the glass container, automatic detection becomes possible by using a detecting means such as a CCD camera.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments. FIG. 1 is a plan view of the detection device 1 of the embodiment, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, FIG. 3 is a top view of the holder 4 with the lid 7 removed, FIG. FIG. 5 is an explanatory view of the detection device 10 according to the embodiment, and FIG. 6 is a perspective view of the holder 13.

The detection device 1 shown in FIGS. 1 to 4 is a defect detection device for a glass substrate for a storage medium, and has a light source 3 and a holder 4. The light source 3 is a linear light source and is stored inside the case. The holder 4 has a flat cylindrical shape, one end of which is connected to the case of the light source 3 and the other end of which the glass substrate 2 is mounted. The light of the light source 3 passes through the inside of the holder 4 and the glass substrate 2
Incident on the outer peripheral side surface 2a. As shown in FIGS. 2 and 3, a portion of the holder 4 on which the glass substrate is mounted wraps substantially half of the outer peripheral portion of the glass substrate 2 by semicircular packings 5 and 6 so that light does not leak. Has become. A cover 7 is provided on the portion, and a packing 6 is provided on the lower surface of the cover 7.
Is glued. The mounting of the glass 2 is performed by opening the lid 7, placing the end of the glass 2 on the packing 5, and covering the lid 7. In addition, in the portion where the glass substrate is mounted, both the main body of the holder 4 and the lid 7 have a semicircular cutout in order to detect light coming out of the surface of the glass substrate. It is not required for both lids, but only for one of them.

As shown in FIG. 2, the glass substrate 2 is
The detection means 9 is provided above the dark box 8 as C.
The CD camera is set. Light emitted from the light source 3 passes through the inside of the holder 4 and enters the outer peripheral side surface 2a of the glass substrate 2 as indicated by an arrow. If there is no defect in the glass substrate, the incident light passes through the inside of the glass while being totally reflected at the interface of the glass, and goes out of the dark box through the exit 8a on the opposite side. In this case, since no light is emitted from the glass surface, the detecting means 9 does not detect the light. When the glass substrate has a defect, light passing through the inside of the glass substrate is irregularly reflected by the defect and emerges from the surface of the glass substrate. Therefore, the detecting means 9 detects the light, and it is detected that the glass substrate has the defect. You.

The detection device 10 shown in FIG. 5 is a defect detection device for a glass container such as a glass bottle and a glass tableware, and has a light source 12 and a holder 13. As shown in FIG. 6, the holder 13 is connected to the light source 12 by an optical fiber 14, and has a ring-shaped light emitting portion 13a on the lower surface. Such a device having a ring-shaped light emitting portion is a known device generally called an optical ring guide. A disc-shaped packing 15 and a ring-shaped packing 16 are attached to the lower surface of the holder 13, and a ring-shaped portion between the packings 15 and 16 serves as the light emitting portion 13a. The mouth of the glass container 11 is mounted in a ring-shaped gap between the packings 15 and 16. A CCD camera is set on the side of the glass container 11 as the detection means 9.

The light emitted from the light source 12 passes through the ring-shaped light emitting portion 13a of the holder 13 and the end face 1 of the mouth of the glass container 11.
1a. If there is no defect in the glass container, the incident light travels downward inside the glass while being totally reflected at the interface of the glass, and no light is emitted from the surface of the glass container, so that the detecting means 9 does not detect the light. . If the glass container has a defect, light passing through the inside of the glass is irregularly reflected by the defect and emerges from the surface of the glass. The detecting means 9 detects the light and detects that the glass container has a defect.

In the glass container 11 shown in FIG. 5, since the boundary between the peripheral wall and the bottom is bent at 90 °, light that has passed through the glass may not be totally reflected at the relevant portion but scattered from the glass surface. is there. In such a case, it is desirable that the mask 18 be placed near the bottom so that light scattered from the vicinity of the bottom is not detected by the detection unit 17. In the case of a shape that transitions smoothly from the peripheral wall to the bottom, such as a hemispherical bowl, light passing through the inside of the glass is totally reflected even near the bottom, passes through the glass, and emerges on the glass surface. Absent.

As described above, various shapes of glass containers can be inspected by using the holder having a shape corresponding to the shape of the mouth of the glass container.

The inspection apparatus of the embodiment is merely an example, and the inspection apparatus of the present invention can be variously modified from the embodiment except for the matters described in the claims. . For example, the light source 3 is not necessarily a linear light source but may be a point light source. A light source case is not necessary. The lid 7 of the holder 4 is not always necessary, and glass may be inserted from the end of the holder 4.

[0025]

The method and apparatus for detecting defects according to the present invention are not affected by dust and dirt on the surfaces of glass substrates and glass containers.
A clean room is not required, and the defect of the glass product can be detected stably and with high accuracy without being affected by individual differences among inspectors. In addition, it is easy to perform an automatic inspection by a detecting means such as a CCD camera.

[Brief description of the drawings]

FIG. 1 is a plan view of a detection device 1 according to an embodiment.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a top view of the holder 4 with the lid 7 removed.

FIG. 4 is an explanatory diagram of a detection method of the present invention.

FIG. 5 is an explanatory diagram of a detection device 10 according to another embodiment.

FIG. 6 is a perspective view of a holder 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Detector 2 Glass substrate 3 Light source 4 Holder 5 Packing 6 Packing 7 Lid 8 Dark box 9 Detecting means 10 Detector 11 Glass container 12 Light source 13 Holder 14 Optical fiber 15 Packing 16 Packing 17 Detecting means 18 Mask F Defect

Claims (6)

[Claims] 1. Light is incident on the outer peripheral side surface of a glass substrate,
A storage medium characterized by detecting a defect of the glass substrate by detecting light out of the light, which is irregularly reflected by a defect inside or on the surface of the glass substrate and emerges from the surface of the glass substrate. Defect detection method for glass substrate 2. A glass substrate for a storage medium, comprising: a light source; and a holder that wraps around the outer peripheral side surface of the glass substrate and prevents light from the light source from being emitted to a portion other than the outer peripheral side surface of the glass substrate. Defect detection device 3. The defect of the glass substrate for a storage medium according to claim 2, further comprising a detecting means for detecting light which is diffusely reflected by the defect of the glass substrate and emerges from the surface of the glass substrate. Detector 4. Light is incident on the end face of the mouth of the glass container,
A glass characterized by detecting a defect of the glass container by detecting light out of the light, which is irregularly reflected by a defect inside or on the surface of the glass of the glass container and emerges from the glass surface of the glass container. Container defect detection method 5. A disadvantage of a glass container comprising a light source and a holder which wraps around the opening of the glass container and prevents light from the light source from being emitted to the end of the glass container other than the end face of the glass container. Detector 6. The detecting apparatus according to claim 5, further comprising detecting means for detecting light which is diffusely reflected by a defect of the glass container and emerges from the surface of the glass container.