JP2526745B2 - Tile unit inspection method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining whether a tile unit produced in a tile unit production process has tiles touching each other or overlapping each other.

[0002]

2. Description of the Related Art FIG. 2 is a plan view showing a tile unit 1. The tile unit 1 has four, nine, or more tiles 2, 2, ... Arranged so that the overall planar shape is a square or a rectangle, and each tile 2, 2 ,.
The connection sheets 3 are attached and connected to each other on the back surfaces or on the glazed surfaces. The connecting sheet 3 is usually made of kraft paper or cloth.

In order to manufacture this tile unit 1, as shown in FIG. 3, the tile 2 is fitted into each grid of the tile alignment board 5 having the grid-shaped partition frame 4, and then the tile 3 is placed.
The sheet 3 is attached so as to straddle it (FIG. 4). Thereafter, the connected body of the tiles 2 is released from the alignment board 5 to obtain the tile unit 1.

[0004]

In the manufacturing process of this tile unit, as shown in FIG.
A defective product may occur due to the tile 2 deviating from the regular position.

Conventionally, such defective products are found and removed by visually inspecting all products, but the labor cost is significantly increased, and the determination is likely to vary.

[0006]

A tile unit inspection method according to claim 1 is a tile unit inspection method in which a plurality of tiles are connected by a sheet, and a tile unit tile in an imaging device having a large number of pixels. The joint at the corner and its vicinity are imaged, the brightness of each pixel on the line intersecting the joint is detected, and if even one of the pixels on the line has a brightness equivalent to the joint, the tiles Is characterized in that it is determined that the two are separated.

The inspection method of the tile unit according to claim 2 is
2. The tile unit inspection method according to claim 1, wherein the entire tile unit is imaged, the position of the edge of each tile is specified from the brightness of each pixel, and the position of the edge is inspected based on the specified position of the edge. The feature is that the joint and its vicinity are set.

[0008]

According to the tile unit inspection method of the present invention, the tile corners of the tile unit are imaged by the image pickup device, and the presence or absence of contact between tiles is determined from the brightness data of each pixel.
That is, the brightness is scanned in the direction crossing the joint, and if the joint is detected as a result, it is determined that the tiles do not abut or overlap each other at the corner portion.

According to this method, the inspection of the tile unit can be automated, and the labor cost can be greatly reduced.

According to the tile unit inspection method of the second aspect, it is possible to reliably select the joint portion of the tile unit, accurately specify the position of the joint to be inspected, and detect the joint width.

[0011]

EXAMPLES Examples will be described below with reference to the drawings.

FIG. 1 is a manufacturing process diagram of a tile unit. As described above, the nine tiles 2 are loaded into the nine tiles of the tile alignment board 5 by the tile transfer machine in the state of being turned over. Then, the sheet 3 is attached so as to connect the nine tiles 2 to each other.

Next, the CCD camera 6 is used for the tile unit 1
Is imaged. 7 is a fluorescent lamp. It is determined from the imaged data whether the product is a non-defective product or a defective product, and the non-defective product is taken out from the aligning board 5 according to the normal route and sent to the shipping process.

The tile unit inspected in this embodiment is composed of nine so-called 100-square tiles of about 100 mm × 100 mm arranged in a square lattice and connected by sheets (see FIG. 2). The CCD camera has a total of 655
36 (256 x 256) or 262144 (512)
X512) or more pixels, and the intensity of light detected by each pixel (reflected light intensity) is 64.
Alternatively, it is converted into a 256-level brightness signal and then input to a computer.

This computer carries out the following processes (1) to (3).

The average brightness of the tile exposed surface at the center of each tile is calculated.

A zone where the lightness is lower than the average lightness by a predetermined value or more is found around the tile, the tile edge is specified, and the center position of the tile is specified from this.

An inspection area is set near the corner of each tile.

With respect to each inspection area, the brightness of pixels located on a line extending in the direction orthogonal to the tile edge is continuously detected. The brightness scanning is performed on the entire inspection area.

If the joint is detected in the scanning direction even at one place, it is determined that there is no contact between the tiles in the corner portion.

Next, the above-mentioned processes (1) to (4) will be individually described in detail.

Calculation of the average brightness of the tile exposed surface in the center of each tile.

Tile unit No. 6 in the center of the 9 tiles
As shown in the figure, a spot area having a diameter of about 30 mm is set, and pixels that sense this area are specified. The number of pixels per spot is 36.

In the computer, the brightness of each spot is calculated so as to average the reflected light intensities of all 36 pixels for each of the above-mentioned areas (spots) defined for each of the nine tiles. The calculated brightness is T _{1 to} T ₉ .

Identification of the center position of the tile. With respect to the central tile, that is, the tile to which T ₅ is added in FIG. 6, a lightness lower than the tile exposed surface lightness T ₅ of the spot portion by a predetermined value is set as the threshold I ₅ . This I ₅
Is a threshold value that distinguishes the tile surface from the joint.

As shown in FIG. 7, check areas K _{1 to} K ₄ of 32 × 12 mm are set in the central portions of the four sides of the square tile.

For each of the check areas K _{1 to} K ₄ ,
Scan across the entire area in the direction transverse to the joint.
Pixels with the threshold value I ₅ or more (tile surface imaging pixels)
Select and calculate the tile edge coordinates.

The center coordinates of the tile surface are calculated from the tile edge coordinates calculated by calculating the four sides of the tile.

From the measured value of one sheet at the center, the others are calculated at a pitch of 100 mm.

Inspection area setting.

The planned center position of the nine tiles is about 1
Although it is a grid point of a grid of 00 mm, the center of the tile is actually deviated from this grid point. Therefore, the tile center coordinates obtained in step 3 are set as the actual tile center position.

Based on the actual position of each tile, 8 × 6 mm inspection areas J _{1 to} J ₂₄ are set in the vicinity of the corners of each tile as shown in FIG. A total of 24 inspection areas are set for each tile unit. Lightness scanning In each of the inspection areas J _{1 to} J ₂₄ , lightness scanning is performed in the direction orthogonal to the joint 8. A large number of line segments 9 in FIG. 10 each represent a scanning line. That is, the brightness of the pixel is detected along each line segment 9.

If the tiles 2 are separated by a distance more than the detectable distance with the joint 8 interposed therebetween, the joint threshold value K ₁ is lowered at at least one position on the scanning line as shown in FIG. When the end faces of the tiles 2 and 2 are in contact with each other, or when one of the tiles 2 is riding on the other tile, the brightness of the pixels on the scanning line 9 running in that portion is all higher than the threshold value K _1. growing.

If scanning is started in one inspection area J _K and a joint is found on the way, the scanning in that area may be stopped. As a precaution, the entire scanning area is scanned. You may.

[0035] In the brightness scanning of the judgment, if the brightness even in one of the total scanning lines 9 of a test region J _K is detected, the tiles 2,2 comrades in the examination region J _K is Judge that there is no contact. When no brightness is detected in all the scanning lines 9 in a certain inspection region J _K , it is determined that the tiles 2 and 2 are in contact (contact or overlapping) in the inspection region J _K.

It is detected how many tiles 2 and 2 are in contact with each other among all the inspection areas J _{1 to} J ₂₄ . If this number exceeds the allowable number (usually 0. If the inspection standard may be weak, for example, 1 or 2), the tile unit is determined as a rejected product.

[0037]

As described above, according to the methods of claims 1 and 2, it is possible to automatically determine the presence or absence of contact between tiles in a tile unit. Particularly, according to the method of claim 2, this determination can be accurately performed. Therefore, according to the present invention,
The quality inspection of tile units can be unmanned, and the quality control level can be made uniform.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of a tile unit.

FIG. 2 is a plan view of a tile unit.

FIG. 3 is a perspective view showing a method for manufacturing a tile unit.

FIG. 4 is a cross-sectional view showing the same method.

FIG. 5 is a plan view of a defective tile unit.

FIG. 6 is a plan view of a tile unit showing measurement spots.

FIG. 7 is a plan view showing a check area.

FIG. 8 is a plan view showing an inspection area.

FIG. 9 is a schematic diagram showing a difference in brightness between a tile and a joint.

FIG. 10 is a plan view showing a scanning line.

[Explanation of symbols]

 1 tile unit 2 tiles 3 sheets 5 tiles alignment board 8 joints 9 scanning line

Claims (2)

(57) [Claims] 1. A method of inspecting a tile unit in which a plurality of tiles are connected by a sheet, wherein an image of a tile unit corner portion of a tile unit and its vicinity is imaged by an image pickup device having a large number of pixels, A tile unit characterized by detecting the brightness of each pixel on the intersecting line and determining that the tiles are separated if one of the pixels on the line has a brightness corresponding to the joint. Inspection method. 2. The method of inspecting a tile unit according to claim 1, wherein the entire tile unit is imaged, the edge position of each tile is specified from the brightness of each pixel, and the position of the edge is specified based on the specified edge position. A method for inspecting a tile unit, wherein a joint to be inspected and a portion in the vicinity thereof are set.