JPH10339622A - Recess and projection inspection method of molding surface and reading methods of cathode-ray tube mark - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily read a mark and to easily find a flaw by applying light from a point- shaped light source at the rear surface side of a thin sheet-shaped molding to the molding from the rear surface, transmitting and refracting it, and forming a real image of light intensity distribution corresponding to the recessed and projected parts of the molding. SOLUTION: The light of a light source L is set to a point-shaped light source 3 at a hold H and is radially applied from the hole H to the rear surface of a thin sheet-shaped molding 1. The applied light is refracted while it is being transmitted through the thin sheet- shaped molding 1, and a real image 4 corresponding to recessed and projected parts 2 is formed behind the thin sheet-shaped molding 1. The image 4 is projected on a translucent screen, light intensity distribution that is clearer than visual inspection is given, and only the real image 4 can be observed without interfering reflected light from a perimeter. An optical system 5 is provided behind the real image 4, an area sensor 6 is provided in the position of a second-stage real image 7 where an image is formed for detecting, and the image is converted to an electronic image. The electronic image is reproduced as an optical image corresponding to the recessed and projected parts 2 so that it can be subjected to visual inspection, thus reducing mutual interference between the thin sheet-shaped molding 1 and the optical system 5 and increasing freedom in inspection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, television tubes, personal computer displays, other glasses,
The present invention relates to a purposeful image and an inspection method for such surface irregularities for identifying or inspecting the presence or absence of irregularities (for example, markings and scratches for inspection) on the surface of a molded article made of plastic or the like.

[0002]

2. Description of the Related Art A glass CRT used for a cathode ray tube, a display of a personal computer, and the like is manufactured by molding using a molten glass mold. The concave and convex engraving is given.

[0003] However, since the stamped portion of the mold is worn by being repeatedly used for molding the CRT, the unevenness of the stamped CRT is gradually reduced according to the number of times the mold is used (50 to 60 microns). Becomes 20 to 30 microns), the sharpness of the stamp is lost, and the reflected light of the light entering from the surroundings becomes an obstacle, making it difficult to read at the time of inspection, and even if the inspection result such as the angle dimension is obtained. However, there is a problem that it is not possible to associate them with the model number / part number.

[0004] The above problems exist not only in the reading of the inscriptions on the glass molded products, but also in the inspection for the presence or absence of flaws generated on them. In other words, the scratches are irrelevant to the number of uses of the mold, and as the number of uses increases, the number,
In some cases, small scratches are not easily found by visual inspection and are easily overlooked.

[0005] Further, plastic molded products are usually engraved for the same purpose as above, and although not as much as glass molded products, with the increase in the number of uses of the mold,
There is a problem in that the mold is worn, the unevenness of the stamp is gradually reduced, and the sharpness of the stamp is lost. In addition, there is also a problem that small scratches are not easily found by visual inspection and are easily overlooked.

[0006]

[Problems to be solved by the invention]

(1) Since the molding die for glass molded products and plastic molding gradually wears according to the number of uses, the irregularities of the stamps for identification of the model number and product number on the surface of the molded product during molding are gradually increased. It becomes smaller, loses its sharpness, and becomes difficult to read during inspection. (2) Furthermore, small scratches generated on the surface of the molded product are not easily found by visual inspection and are easily overlooked.

The present invention provides a method that can solve these problems, that is, it makes it extremely easy to read an inscription on a transparent or translucent thin plate made of glass or plastic and to find a scratch. The purpose is to provide a method that can be used.

[0008]

[Means for Solving the Problems]

(First Means) The method for inspecting the unevenness of the surface of a molded article according to the present invention is a method for inspecting the unevenness (2) on the surface of a transparent or translucent thin sheet-shaped molded article (1). A substantially point-like light source (3) is arranged on the back side of the product (1), and (B)
The light emitted from the light source (3) is applied to the sheet-like molded product (1) from the back side, transmitted and refracted, and (C) the unevenness (2) of the sheet-like molded product (1) A corresponding real image (4) having a light intensity distribution is formed.

That is, in order to achieve the above object, the present invention provides a method for imaging the irregularities 2 on the surface of a transparent or translucent thin plate-shaped molded product 1. A substantially point-like light source 3 is disposed, and light emitted from the light source 3 is irradiated from the back side of the thin plate-shaped molded product 1 and refracted while transmitting the light. (A) A real image 4 corresponding to the unevenness 2 of the thin plate-shaped molded product 1 is formed behind the thin plate-shaped molded product 1 according to the preceding paragraph.

Since the real image 4 corresponding to the irregularities 2 has a clearer light intensity distribution than visual observation, it is easier to read or to discover than the conventional direct observation of the irregularities 2 by visual observation. . (Second Means) The method for inspecting the surface unevenness of a thin plate-shaped molded product according to the present invention comprises the steps of: (A) refracting light incident through a position connecting a real image 4 in the first means so that the light is converged by an optical system 5; Then, a second-stage real image 7 is formed on the area sensor 6, and (B) the second-stage real image 7 is detected.
It is characterized in that it is converted into an electronic image.

That is, the second means includes the first means,
Further, the light incident through the position connecting the real images 4 is refracted by the optical system 5 so as to be converged, and then guided to the area sensor 6, where the second-stage real image 7 is formed and imaged.

[0012] If necessary, an operation of converting the image into an electronic image is added. (Third Means) The method for inspecting the unevenness of the surface of a thin plate-like molded product according to the present invention comprises: (A) a method of inspecting the surface unevenness 2 of a transparent or translucent thin plate-like molded product; 1. A substantially point-like light source 3 is disposed on the back surface side of (1), and (B) the light emitted from the light source 3 is radiated to the thin plate-shaped molded product 1 from the back side and transmitted and refracted. A real image 4 having a light intensity distribution corresponding to the irregularities 2 of the thin plate-shaped molded article 1 is formed. (D) Light incident through a position connecting the real images 4 is refracted by an optical system 5 so as to converge. , And is projected on a translucent screen 8. (Fourth Means) A method for reading a tube stamp according to the present invention is as follows.
(A) An approximately point light source 3 is arranged on the back side of a cathode ray tube,
(B) The light emitted from the light source 3 is irradiated from the back side of the cathode ray tube, transmitted and refracted.
(C) A real image 4 having a light intensity distribution corresponding to the marking of the cathode ray tube is formed.

Therefore, the operation is as follows. (1) According to the first means, the real image 4 corresponding to the unevenness 2
For example, when projected on a translucent screen, has a clearer light intensity distribution than visually, and
Since only the real image 4 can be observed without interference of the reflected light of the light entering from the surroundings, even if the mold is worn and the unevenness of the stamp is gradually reduced, it is compared with the conventional direct observation of the unevenness 2 by visual observation. Then, it is easy to read the engraved mark or to easily find a minute scratch. (2) Further, according to the second means, the optical system 5 is disposed at a position where the real image 4 is formed away from the thin plate-shaped molded product 1, and the area sensor 6 is disposed behind the optical system 5. The finger-to-finger interference between the thin plate-shaped molded product 1 and the optical system 5 is small,
The degree of freedom of reading and inspection work is increased. (3) According to the third means, a simple and inexpensive screen 8 is provided instead of the complicated and expensive area sensor 6. Compared with the second means, the cost of the apparatus is reduced. (4) According to the fourth means, the real image 4 corresponding to the CRT stamp has, for example, a clearer light intensity distribution than projected by projection when projected on a translucent screen,
Moreover, since only the real image 4 can be observed without being affected by the reflected light of the light entering from the surroundings, even if the unevenness of the engraving becomes smaller gradually, the engraving is performed in comparison with the conventional direct observation of the unevenness 2 by visual observation. Easy to read. Alternatively, it is easy to find even small scratches.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a view showing the original embedding of the device according to the first embodiment of the present invention.

On the left side of the center of FIG. 1, a transparent or transparent thin plate-shaped molded product 1 is placed. The thin plate-shaped molded product 1 is placed so that the surface having the irregularities 2 of the thin plate-shaped molded product 1 is on the right side and parallel to the vertical direction.

As the thin plate-shaped molded product 1, a glass molded product or a plastic molded product generally molded by a metal mold such as a CRT made of glass is intended, but is not necessarily limited thereto. .

As the unevenness 2, for example, for inspection or quality assurance, a mark generated by the same mold, such as a model number and a product number, or a scratch caused by the mold or other causes is considered.
Other equivalents are also included.

A light source L is placed on the leftmost end, and an opaque vertical plate P is placed on the right side of the light source L, and a small hole H is formed in the vertical plate P. The light passing through the hole H is configured to function as a substantially point light source 3 that enters the thin plate-shaped molded product 1 from the back side.

In the above configuration, when the light source L is turned on, the light becomes the substantially point light source 3 by the hole H, and the light is directed rightward from the hole H toward the back surface of the thin plate-shaped molded product 1 as shown in FIG. Irradiated radially.

The emitted light is refracted while passing through the thin plate-shaped molded product 1, and forms a real image 4 corresponding to the irregularities 2 slightly behind (several millimeters behind) the thin plate-shaped molded product 1. When the real image 4 is projected on, for example, a translucent screen 7 described later, the real image 4 has a clearer light intensity distribution than visually, and does not receive interference of reflected light of light entering from the surroundings. 4 becomes observable, so that even if the mold is worn and the asperities of the stamp become smaller gradually, the conventional asperities 2
The mark is easier to read or a minute flaw is easier to find as compared with direct observation by visual observation.

Further, an optical system 5 for refracting the incident light so as to converge the incident light is provided behind the position where the real image 4 is formed, and an area sensor 6 is disposed further behind the optical system 5.

Accordingly, the light that enters the optical system 5 through the position connecting the real image 4, transmits the light, and is refracted further forms the second-stage real image 7. Second stage real image 7
The area sensor 6 is disposed at a position connecting
The second stage real image 7 is detected and converted to an electronic image.

This electronic image is visually reconstructed as an optical image corresponding to the irregularities 2 by a converter not shown in FIG. According to the above configuration, while the position where the real image 4 is formed is very close to the thin plate-shaped molded product 1, the optical system 5 is arranged at a position away from the thin plate-shaped molded product 1 in front of it. Further, since the area sensor 6 is disposed behind the sensor, mutual interference between the thin plate-shaped molded product 1 and the apparatus of the present invention, particularly, the optical system 5, is reduced, and the degree of freedom of reading and inspection work is increased. (Second Embodiment) A second embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a view showing the original embedding of the apparatus according to the second embodiment of the present invention. As shown in FIG. 2, the configuration on the left side of the optical system 5 is the same as that in FIG.

Referring to the right side from the center of FIG.
Instead of the area sensor 6, a translucent screen 8 for projecting the second-stage real image 7 is arranged. It should be noted that a photographing device (not shown in FIG. 2) may be arranged behind the screen 8 so that an image corresponding to the unevenness can be viewed through the photographing device.

According to the above configuration, since the screen 8 is simple and inexpensive, the burden on the apparatus is reduced even when including a photographing apparatus (not shown) as compared with the screen having the complicated and expensive area sensor 6. You can do it.

The effect of the size of the hole H of the vertical plate P on the image will be described.
The image corresponding to becomes dense, and when reading the engraved,
Because fine scratches on the surface appear clearly. The hole H is preferably slightly larger because the engraving may be blurred and reading may be difficult. Therefore, conversely, when inspecting a fine flaw, it is desirable to reduce the diameter of the hole H.

[0028]

Since the present invention is configured as described above, it has the following effects. (1) Even if the mold is worn and the unevenness of the mark becomes gradually smaller, the mark becomes easier to read as compared with the conventional direct observation of the unevenness 2 by visual observation.

Further, it is easy to find even small scratches. (2) Interference between the thin plate-shaped molded product 1 and the apparatus of the present invention is small, and the degree of freedom of reading and inspection operations can be increased. (3) By providing a simple and inexpensive screen 8 instead of the complicated and expensive area sensor 6, the cost of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a view showing an original embedding of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an original embedding of an apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Thin-plate-shaped molded product 2 ... Unevenness 3 ... Light source 4 ... Real image 5 ... Optical system 6 ... Area sensor 7 ... Second stage real image 8 ... Screen H ... Hole L ... Light source P ... Vertical plate

Claims (4)

[Claims] 1. A method for inspecting the surface irregularities (2) of a transparent or translucent thin plate-like molded product (1), comprising: (A) a substantially point-like light source ( And (B) irradiating the light emitted from the light source (3) to the thin plate-shaped molded product (1) from the back side and transmitting and refracting the light; and (C) the thin plate-shaped molded product. A method for inspecting unevenness of a molded product surface, wherein a real image (4) having a light intensity distribution corresponding to the unevenness (2) of (1) is formed. (A) A light incident through a position connecting the real image (4) according to claim 1 is refracted so as to be converged by an optical system (5), and is refracted by a second stage on an area sensor (6). A method for inspecting irregularities on the surface of a thin plate-shaped molded product, wherein a real image (7) is formed, and (B) the second-stage real image (7) is detected and converted to an electronic image. 3. A method for inspecting unevenness (2) on the surface of a transparent or translucent thin plate-like molded product (1), wherein (A) a substantially point-like light source ( And (B) irradiating the light emitted from the light source (3) to the thin plate-shaped molded product (1) from the back side and transmitting and refracting the light; and (C) the thin plate-shaped molded product. A real image (4) having a light intensity distribution corresponding to the unevenness (2) of (1) is formed, and (D) light incident through a position connecting the real image (4) is converged by the optical system (5). A method for inspecting unevenness of the surface of a thin plate-shaped molded product, wherein the surface is refracted and projected onto a translucent screen (8). 4. A method for reading a tube engraved mark, wherein (A) a substantially point-like light source (3) is arranged on the back side of the cathode ray tube, and (B) light emitted from the light source (3) is irradiated from the back side of the cathode ray tube. And (C) forming a real image (4) having a light intensity distribution corresponding to the engraving on the cathode ray tube.