JP2002005638A - Method and apparatus for inspecting sheet-like work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance inspection accuracy, when a sheet-like work is inspected by inputting the image thereof, even when the work is deformed or deflected. SOLUTION: The apparatus for inspecting a sheet-like work W, mounted on an inspection stage 14 while being applied with a glass plate 16, based on an image picked up by means of a line sensor camera 10 disposed above the stage, while moving the camera along the stage comprises a roller 18 which comes into contact with the surface of the glass plate 16, and a damper 20 for pressing the surface of the glass plate located close to the field of view of the camera by means of the roller with a substantially constant pressing force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for inspecting a sheet-like work, and more particularly to a method and an apparatus for inspecting a sheet-like work suitable for use in inspecting a sheet-like work such as a lead frame by image processing. .

[0002]

2. Description of the Related Art As shown in FIG. 6, a sheet-like work W such as a lead frame is generally imaged by a line sensor camera (imaging means) 10 under the illumination of coaxial epi-illumination 12, and an obtained image is obtained. Inspection and processing are performed.

[0003] However, the work W is often slightly deformed due to bending of the base material, handling during the manufacturing process, and the like. Therefore, as described above, the illumination light from the coaxial epi-illumination 12, that is, the illumination light from the light source (not shown) is reflected by the half mirror 12A, and under the epi-illumination in which the surface of the work W is irradiated in the first half, FIG. When the image is captured by the line sensor camera 10 as shown in FIG. 1, simply placing the work W on the inspection stage will cause the surface state to show the brightness difference as shown in FIG. May have an effect
This is the cause of false detection.

In order to suppress the deformation and deflection of the work W, the work W placed on the inspection stage 14 is placed on the glass plate 1 as shown in FIG.
6, and similarly sandwiched between the glass plates 16 as shown in FIG. 9, and a peripheral portion that does not catch on the work W is bolted through a frame portion (not shown) by a bolt 17 or a clamp lever (not shown) or the like. Clamping and holding are performed.

[0005]

However, when the sheet-like work W is sandwiched between the glass plates 16 as described above, the work W is pressed down from above only by the pressure of its own weight. Therefore, the effects of deformation and the like cannot be completely suppressed.

Further, as described above, the work W is placed on the glass plate 16.
In the case where the pressure for holding the work W is increased by clamping the periphery of the work W through the frame after being sandwiched by the frame, the force is not sufficiently transmitted to the center of the work W only by the clamp of the frame. Therefore, the effect of the clamp cannot be exerted over the entire surface of the work W.
The effects of deformation and deflection cannot be completely eliminated. In addition, if the peripheral portion is strongly sandwiched, there is no escape for the deflection of the material itself in the central portion, so that there is a problem that a portion where the deflection is concentrated and deformed easily occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and when a sheet-shaped work is input as an image and inspected, the inspection accuracy is improved even if the work is deformed or bent. An object of the present invention is to provide a method and an apparatus for inspecting a sheet-like work that can be improved.

[0008]

According to the present invention, a sheet-like work placed on an inspection stage and sandwiched between the stage and a glass plate superposed thereon is disposed above the stage. In the inspection method of a sheet-like work, in which the imaging means is imaged while moving the imaging means along the same stage, and the work is inspected based on the obtained image, a roller contacting the surface of the glass plate Is rotated together with the imaging means, the surface of the glass plate located near the visual field of the imaging means by the roller,
The above problem has been solved by pressing with substantially the same pressing force.

According to the present invention, there is also provided an image pickup means disposed on an inspection stage, wherein the sheet-like work sandwiched between the stage and a glass plate superposed thereon is arranged above the stage. According to the sheet-like work inspection apparatus for imaging while moving the imaging unit along the stage and inspecting the work based on the obtained image, a roller contacting the surface of the glass plate, the roller A moving means for rotating and moving together with the imaging means, and a pressing means for pressing the surface of the glass plate located near the visual field of the imaging means by the rollers with substantially the same pressing force. The above-mentioned problem has been solved.

That is, according to the present invention, when a sheet-like work sandwiched between an inspection stage and a glass plate superposed thereon is imaged from above by the imaging means, the vicinity of the visual field of the means is determined. The surface of the glass plate located at any position on the work can be pressed by a roller with substantially the same pressing force, so even if the work is deformed or bent,
It is possible to always take an image under a constant condition over the entire range, and it is possible to improve the inspection accuracy.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic side view showing a main part of a thin metal sheet (sheet-like work) appearance inspection apparatus according to a first embodiment of the present invention.

The inspection apparatus of this embodiment has a coaxial line sensor camera (imaging means) 10 substantially the same as that shown in FIG. 6 and a half mirror 12A for reflecting illumination light from a light source. 8, and a sheet-like sheet placed on the inspection stage 14 and sandwiched between the stage 14 and the glass plate 16 superposed thereon, as in the case of FIG. The work W can be imaged by the line sensor camera 10.

In this embodiment, the line sensor camera 10 and the coaxial epi-illumination 12 are integrally formed via a support member 13, and the illumination 12 is brought into contact with the surface of the glass plate 16. Roller 18 is
Attached via a damper (pressing means) 20, these line sensor camera 10, coaxial epi-illumination 12, roller 18
The damper 20 and the damper 20 together constitute an input unit 22.

The input unit 22 is moved up and down by a stage 24 for moving up and down.
When the unit 22 is set at a fixed height with respect to the glass plate 16, the roller 18 can contact the surface of the glass plate 16 with a substantially constant pressing force. ing. Also, when the line sensor camera 10 does not take an image, the roller 18 can be moved to a position where the roller 18 does not come into contact with the surface of the glass plate 16 by the stage 24 for vertical movement.

FIG. 2 shows an outline of the whole inspection apparatus of the present embodiment by image, and FIG. 3 is a control block diagram thereof.

In this inspection apparatus, the input unit 22 shown in FIG.
In addition to being movable up and down by the axis stage, the X-axis stage 26 and the Y-axis stage 28 scan (move) along the surface of the glass plate 16 on the inspection stage 14, that is, the work W in the direction of the arrow. The entirety of the work W can be sequentially imaged by the line sensor camera 10.

In the inspection apparatus of the present embodiment, the X-axis stage 26, the Y-axis stage 28 and the Z-axis stage 24
Are controlled by the stage controller 30, and when the respective stages are controlled and imaged, the control unit / image processing unit 32 processes the input image to perform the inspection. ing.

Next, the operation of the present embodiment will be described.

First, the operator places the sheet-like work W at a predetermined position on the inspection stage 14 automatically or manually, and the input unit 22 is moved by the Z-axis stage 24 so that the roller 18 is moved to the upper surface (surface) of the glass plate 16. The roller 18 is moved to the inspection start position in a state in which the roller 18 is raised to a position where the roller 18 does not come into contact, and then the roller 18 is lowered to a position where it comes into contact with the upper surface of the glass plate 16. Thereafter, while moving the workpiece W on the X-axis stage 26 and the Y-axis stage 28, the workpiece W is captured and an image is captured, and the captured image is sent to the image processing unit 32.
The inspection is performed, and when a defect is detected, information on the position is recorded.

FIG. 4 shows a specific example of the inspection process performed while moving the input unit 22. That is, the image of the work W is captured by the line sensor camera 10 (step 2). Here, in the case where a minute hole that does not penetrate the target surface is detected as a defect, when the image is captured under the coaxial epi-illumination 12, the defective portion becomes dark.

Next, in order to improve the inspection accuracy, preprocessing such as noise removal and position correction is performed on the captured image (step 4).

Thereafter, after the image is captured within a predetermined range, the image is binarized using a preset threshold (step 6), and the binarized image area is labeled (step 8), and the labeling is performed. A pass / fail judgment is made based on the area of the region thus determined. As described above, the inspection processing described above is performed on the entire surface of the work W by repeating the movement and the imaging in the inspection in units of the predetermined range (step 1).
0).

As described above, the final judgment at the time of the inspection based on the input image may be automatically performed based on the position of the defect, the number of occurrences, or the like, or may be determined by the judgment of a person.

According to the above-described embodiment, the workpiece W is imaged by the line sensor camera 10 while the glass 16 near the visual field of the line sensor camera 10 is constantly pressed down by the roller 18 with a constant pressing force. By doing so, it is possible to always input an image of a fixed image quality regardless of the location of the work W, so that the inspection accuracy can be improved.

FIG. 5 shows the coaxial epi-illumination 12 and the rollers 18 of the input unit 22 included in the inspection apparatus according to the second embodiment of the present invention.

The inspection apparatus of the present embodiment has two rollers 1
8 is an arm 1 rotatably supported by the illumination 12
8A and both arms 1
Except that the surface of the glass plate 16 can always be pressed down by the roller 18 with a constant pressing force by the spring (pressing means) 34 engaged between 8A.
This is substantially the same as the first embodiment.

Although the present invention has been specifically described above, the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the gist thereof.

For example, as the pressing means, the damper 20 is used.
The spring and the spring 34 are not limited and may be any as long as they have the same function.

Further, as the roller, an adhesive roller whose surface is formed of an adhesive material capable of cleaning the glass surface may be employed. In this case, since the glass surface can be cleaned almost simultaneously with the imaging of the work W, there is also an advantage that erroneous detection due to the influence of foreign matter can be reduced.

Although a line sensor camera is shown as the image pickup means, an area sensor camera may be used. or,
The illuminating means is not limited to the above-mentioned coaxial incident illumination, but may be a transmissive illumination for illuminating the work from below.

[0032]

As described above, according to the present invention,
When inspecting a sheet-like work by inputting an image, even if the work is deformed or bent, the inspection accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an enlarged main part of an inspection apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an outline of the entire inspection apparatus of the present embodiment.

FIG. 3 is a block diagram illustrating an outline of a control system of the inspection apparatus according to the embodiment;

FIG. 4 is a flowchart showing a processing procedure of an inspection according to the embodiment;

FIG. 5 is a schematic side view showing an enlarged main part of an inspection apparatus according to a second embodiment of the present invention.

FIG. 6 is a schematic side view showing a conventional image input method in an image.

FIG. 7 is an explanatory diagram showing a conventional problem as an image.

FIG. 8 is an explanatory diagram showing an image of a conventional work set method.

FIG. 9 is an explanatory view showing another method of a conventional workset using an image.

[Explanation of symbols]

 W ... Sheet work 10 ... Line sensor camera 12 ... Coaxial epi-illumination 14 ... Inspection stage 16 ... Glass plate 18 ... Roller 20 ... Damper 22 ... Input unit 24 ... Vertical movement (Z axis) stage 26 ... X axis stage 28 ... Y-axis stage 34 ... spring

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahiko Soeda 1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (72) Inventor Masashi Nishida 1-chome, Ichigaya-cho, Shinjuku-ku, Tokyo No. 1 Dai Nippon Printing Co., Ltd. F-term (reference) 2F065 AA49 AA58 BB01 CC02 DD00 FF01 HH00 HH13 JJ02 JJ25 LL00 LL02 MM07 PP04 PP24 QQ00 QQ05 QQ34 UU04 2G051 AA90 AB02 AC15 CA03 CA04 EA11 EB11

Claims (10)

[Claims] 1. An image pickup device arranged above an inspection stage, wherein a sheet-like work placed on an inspection stage and held between the stage and a glass plate overlaid on the inspection stage is imaged by the imaging means. In the method of inspecting a sheet-like work for imaging while moving the means along the same stage and inspecting the work based on the obtained image, a roller contacting the surface of the glass plate is rotationally moved together with the imaging means. A sheet-like work inspection method, wherein the roller presses the surface of the glass plate located near the visual field of the imaging means with substantially the same pressing force. 2. The method according to claim 1, wherein the roller is formed integrally with an input unit including the imaging unit. 3. The apparatus according to claim 2, wherein said roller is mounted on said input unit via a pressing means.
Inspection method of the sheet-like work described in 1. 4. The inspection method of a sheet-like work according to claim 2, wherein the input unit includes a coaxial incident illumination, and the roller is attached to the illumination. 5. The inspection method according to claim 3, wherein the pressing means includes a damper or a spring. 6. A sheet-like work placed on an inspection stage and held between the stage and a glass plate superimposed on the stage by an image pickup means arranged above the stage. In a sheet-like work inspection apparatus for imaging while moving means along the same stage and inspecting the work based on the obtained image, a roller contacting the surface of the glass plate; A sheet-like work comprising: moving means for rotating together with the pressing means; and pressing means for pressing the surface of the glass plate located near the visual field of the imaging means by the roller with substantially the same pressing force. Inspection equipment. 7. The inspection apparatus according to claim 6, wherein the roller is formed integrally with an input unit including the image pickup unit. 8. The apparatus according to claim 7, wherein said roller is attached to said input unit via a pressing means.
The sheet-like work inspection apparatus according to any one of the preceding claims. 9. The sheet-like work inspection apparatus according to claim 7, wherein the input unit includes coaxial incident illumination, and the roller is attached to the illumination. 10. The inspection apparatus according to claim 8, wherein the pressing means includes a damper or a spring.