TWI610075B - Film inspection device and film inspection method - Google Patents

Abstract

Due to the high added value associated with film applications, It is also required to have a high degree of accuracy, and it is necessary to inspect small irregularities that are deformed very shallowly. Therefore, a thin film inspection device and inspection method are provided.

The present invention is formed as a thin film inspection device, which It is provided with: a light source; a circular aperture that removes the scattered light component of the light emitted by the light source; a plate lens having a thickness of a plate shape and a convex shape on the side formed into parallel light by the light passing through the circular aperture; Convex lenses are lenses of the same shape that are set facing each other and that converge light; a knife edge that removes scattered light components at the focal point of the focused light; and imaging that captures the light that has been focused The lens inspects the above-mentioned parallel light through a film to be inspected.

Description

Film inspection device and method

The present invention relates to a thin-film inspection device and a thin-film inspection method capable of inspecting uneven defects occurring during the manufacturing stage of a thin film such as a polarizing film and an optical film in a manufacturing process.

Conventionally, shallow unevenness defects occurring in a thin film are visually inspected in a state close to a final product such as a liquid crystal television or a smartphone.

However, the inspection system of the inspection device is extremely difficult, and the in-line inspection at the early stage of the manufacturing process cannot be realized.

In addition, there is an inspection device that uses the same method as the projection method used for streak inspection of glass, etc., but the inspection range is small, and in-line inspection cannot be applied.

Therefore, the present invention provides a thin film inspection device and a thin film inspection method that are based on a Schlieren optical system and are compatible with a line sensor camera used in thin-line inspection.

In addition, a convex lens is made of acrylic lens or resin Fresnel lens instead of a glass lens, thereby making it practical and large.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2000-275188

A defect inspection device used in a thin film manufacturing line is mainly a person using a line sensor camera.

Film defects include foreign matter, insects, and undissolved defects of raw materials, that is, gel or fish eye, damage, and unevenness.

In the lighting, a fluorescent lamp, a halogen lamp, or a metal halide lamp is used as a light emitting source, a linear light guiding light source using linearly arranged optical fibers and irradiating, a linear LED light source having LED chips arranged, and the like.

In the conventional technology, depending on the type of defect, it is difficult to detect if there are no plural optical systems such as an optical system for detecting foreign bodies, insects, gels, an optical system for detecting damage, and an optical system for detecting unevenness.

In addition, it has been suggested that if a special light source such as obliquely irradiating the irradiation direction of the illumination to the damage is not used, the irradiation method or inspection method that is difficult to detect and is specialized to a defect type is used.

Along with the high added value of film applications, high levels of film accuracy are also required, and it is necessary to check for small irregularities such as very shallow deformation.

According to the first invention of the present invention, a thin-film inspection device is provided, which is provided with: a light source; a circular aperture that removes scattered light components of light emitted from the light source; and the light passing through the circular aperture is formed into parallel light. A convex lens having a thickness of a plate shape and a convex shape on the side; a lens having the same shape as the aforementioned convex lens is arranged in a facing manner, and a convex lens that focuses light; removes scattering at a focal position of the light after the light is collected A knife edge of a light component; and an imaging lens that captures the collected light, and passes the parallel light through a film as an inspection target to perform inspection.

According to a second aspect of the present invention, a thin-film inspection device is formed by forming a convex lens having a thickness of a plate-like shape and a convex side surface using an acrylic material.

According to a third aspect of the present invention, a thin-film inspection device is formed by forming the imaging lens into a single focus lens.

According to a fourth aspect of the present invention, a thin-film inspection method is provided. The thin-film inspection method includes: a light source; a circular aperture that removes a scattered light component of light emitted by the light source; and the light passing through the circular aperture is formed as parallel light A convex lens having a thickness of a plate shape and a convex shape on the side; a lens having the same shape as the aforementioned convex lens is arranged in a facing manner, and a convex lens that focuses light; removes scattering at a focal position of the light after the light is collected A knife edge of a light component; and a thin film inspection device of an imaging lens that captures the collected light, passes the parallel light through the thin film as an inspection target, and moves the thin film to continuously inspect the thin film.

According to the present invention, it is possible to provide a thin film inspection device capable of simultaneously inspecting small defects such as damage, or defects with shallow unevenness by using a combination of parallel light and the schlieren effect obtained by a knife edge and the focus obtained by a single focus lens. And thin film inspection methods.

1‧‧‧ light source

2‧‧‧ circular aperture

3‧‧‧ convex lens

4‧‧‧ convex lens

5‧‧‧Blade

6‧‧‧ camera lens

7‧‧‧ Line Sensor Camera

8‧‧‧ Slide

FIG. 1 is a side view of a thin film inspection apparatus of the present invention.

Fig. 2 is a top view of a thin film inspection apparatus of the present invention.

FIG. 3 is a flowchart showing a flow after imaging.

In FIGS. 1 and 2, 1 is a light source, and an LED, a halogen lamp, or a metal halide lamp is used to form a point-like light emitting state. In order to establish an optical system, point light sources are extremely important.

2 is a circular diaphragm, and the scattered light component of the light emitted from the light source 1 can be removed. For a circular aperture, for example, the smaller the diameter of the point light source generated by the circular aperture, the more vivid the image becomes. However, if the diameter is reduced, the amount of light will decrease, and the camera on the light receiving side will not be able to image. Therefore, the diameter is preferably about 0.5 mm to 3.0 mm, for example.

Reference numeral 3 is a convex lens, and the lens shape is formed into a plate shape having a thickness of about 20 mm to 30 mm when measuring parallel light with a line sensor, and is formed as a convex lens having a convex side surface.

In addition, when the overall shape of a convex lens is enlarged, generally, materials such as glass are used to make it. However, it is difficult to manufacture a lens having a width (diameter) of 200 mm or more in terms of cost or practicality. In the present invention, a transparent acrylic material or the like is used as the lens material. The convex lens also includes a plano-convex lens, a lenticular lens, and a Fresnel lens.

4 is a convex lens, and is a lens having the same shape as the convex lens 3. The convex lens 3 and the convex lens 4 are arranged to face each other. Thereby, parallel light can be formed between the convex lens 3 and the convex lens 4. This parallel light is transmitted through the thin film to be inspected, and thin film inspection can be performed.

5 is a knife edge, and the effect of blocking the scattered light can be obtained by being prepared at the light collecting position.

Reference numeral 6 is an imaging lens that forms a portrait into an in-line sensor camera 7.

7 is a line sensor camera, which captures images.

8 is a slider, which has the function of moving the inspection film.

The imaged data obtained by the line sensor camera is sent to the image processing board.

In the image processing board, image processing corresponding to the defect image is performed, the defect location is specified, and the defect portion is specified by the classification of the shape.

As shown in FIG. 3, the post-imaging processing is to perform shading correction on the captured image and perform image processing.

After that, a three-dimensional processing is performed through a two-dimensional filter.

In addition, through the size filter, the defective part is identified, the image of the defective part is cut out, the defect is distinguished, the classification is performed by the size of the defect, the defective part is displayed, and an external warning is issued.

[Example 1]

For example, an image of an inspection using the film inspection apparatus of the present invention is shown.

An image of each of the sample films No. 01, 02, and 03 is shown.

In addition, as a comparative example, the inspection results obtained by the conventional inspection device (the conventional optical system 1 transmission, the conventional optical system 2 diffuse transmission, the conventional optical system regular reflection) and the microscope (x30) are also displayed. Camera portrait.

In the inspection image (inventive optical system) of the film inspection device of the present invention, in any of the three types of samples, a depression is also reflected in the center of the image, and the film defects can be clearly displayed.

In contrast, none of the comparative examples (the conventional optical system 1 transmission, the conventional optical system 2 diffuse transmission, the conventional optical system regular reflection, microscope (x30)) showed no defects.

Therefore, in the present invention, inspection can also be performed for defects that could not be inspected in the past, and inspection can be performed with high accuracy.

[Industrial availability]

The present invention provides a thin film inspection device and inspection method capable of simultaneously inspecting small defects such as damage, or defects with shallow irregularities.

1‧‧‧ light source

2‧‧‧ circular aperture

3‧‧‧ convex lens

4‧‧‧ convex lens

5‧‧‧Blade

6‧‧‧ camera lens

7‧‧‧ Line Sensor Camera

8‧‧‧ Slide

Claims (2)

A thin-film inspection device, comprising: a light source; a circular aperture that removes scattered light components of light emitted by the light source; and a plate having a thickness and a side surface having a thickness of parallel light formed by the circular aperture. A convex lens that is convex; a convex lens that has the same shape as the convex lens and is configured to face and concentrate light; a knife edge that removes scattered light components at the focal position of the collected light; and An imaging lens that captures light with the collected light, passes the parallel light through a film as an inspection target, and inspects irregularities that occur during the manufacturing stage of the film during the manufacturing process. A thin film inspection method using a light source, a circular aperture that removes scattered light components of light emitted by the light source, and a plate having a thickness and a side surface with parallel light formed by the light passing through the circular aperture. A convex convex lens; a convex lens having a lens having the same shape as the convex lens in an opposite manner and condensing light; a knife edge that removes scattered light components at the focal position of the collected light; and The film inspection device of an imaging lens that performs imaging with the light after the light passes the parallel light through the film as an inspection target to move the film, thereby continuously inspecting the irregularities that occur during the production of the film during the manufacturing process.