JPS61170637A - Method and device for detecting front and rear faces of tile - Google Patents

Abstract

PURPOSE:To detect the front and rear faces of a tile by irradiating light with inclined angle on the tile surface to move in a fixed direction and by detecting the brightness difference on the tile surface by passing through the tile surface under a visual sensor. CONSTITUTION:A tile 10 is transferred in the arrow mark direction by a belt 1. The photoelectric switch for detection of a tile connected to a photodetector 4b is turned on at the time when the tip 10a of the tile 10 cuts off the light between a light projector 4a and photodetector 4b, and the detection of the difference of brightness on the surface of the tile 10 by the light irradiated from the light source 2 of 60W is started. A visual sensor 3 transmits to a digitization converting part 7 the brightness signal by catching the differential brightness of the surface of the tile 10. The converting part 7 converts the brightness signal into digital signal and transmits to a front and rear face deciding part 8. The deciding part 8 counts the digital signals from the time when the light between the projector 4a and detector 4b is cut off by the tile 10 until the finishing of its cut-off. It is then compared with the reference value and the front and rear faces of the tile is decided.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method and apparatus for detecting the front and back sides of tiles, particularly unglazed tiles that have irregularities such as ridges on one side. Specifically, the present invention relates to a method and apparatus for detecting the front and back sides of a tile that has an uneven portion on one side that causes a dark area due to a shadow caused by an oblique light beam to the tile surface.

BACKGROUND OF THE INVENTION A conventional device for determining whether a tile is front or back uses a difference in reflectance (the presence or absence of gloss) t between the front and back surfaces of a glazed tile to detect the front and back sides.

Problems to be Solved by the Invention The above-mentioned equipment can only be applied to tiles that have been glazed and fired, and cannot be applied to unglazed unglazed tiles because there is no difference in gloss between the front and back surfaces. . Therefore, the identification of the front and back sides of unglazed ceramics was done visually. On the other hand, determining whether the unglazed product is front or back is important in the tile manufacturing process because the glaze is applied to the front side of the tile, so it is necessary to send the unglazed product to the glazing process with the top surface facing up. The inspector's visual judgment of front and back is inefficient and contributes to lowering the tile manufacturing efficiency.

Accordingly, a main object of the present invention is to provide a method and apparatus for automatically detecting the surface and surface of tiles, including unglazed unglazed tiles.

Another object of the present invention is to provide a method and apparatus for automatically and reliably feeding unglazed tiles with their upper surfaces facing up to the glazing process.

Means for Solving the Problem The present inventor discovered that when light is projected onto a tile surface at a certain angle, a shadow is produced on the back surface of the tile due to irregularities such as the backside of the surface, and that this shadow is detected by a visual sensor. The inventors have discovered that it is possible to determine whether a tile surface is front or back by sensing the tile surface, and have arrived at the present invention.

That is, the method of the present invention irradiates light onto a tile surface moving in a certain direction at an angle of inclination to the tile surface, and detects the brightness difference that may occur due to the irradiation of the tile surface with a visual sensor at a predetermined position. , the front and back of tiles with different surface conditions.
It is characterized by determining the back side.

The above method includes: (1) a tile conveying belt 1; (2) a light source 2 for irradiating light at an oblique angle to the tile surface on the belt; and (2) detecting the difference in brightness in the direction of the moving tile irradiated with light. This is carried out by a detection device having a visual sensor 3 installed at a predetermined position above the belt 1, and a determiner 8 that determines whether the tile surface is front or back based on the difference in brightness detected by the visual sensor. can.

By installing a light emitter 4a on the lower side and a light receiver 4b on the upper side across the position of the tile conveying belt 1 which is below the visual sensor (that is, under the sensing area of the visual sensor), the belt 1 The time when the upper tile begins to pass under the visual sensor 3 (that is, the time when it begins to pass through the bright/dark detection area of the visual sensor) and the time when it finishes passing is detected, and detection by the visual sensor 3 is started and ended by this detection. can be done.

Further, a reversing machine 6 is provided at a position downstream of the visual sensor 3 of the tile conveying belt 1, so that when the tile is conveyed with the back side facing up, the tile is reversed via the control device. Can be configured.

The light irradiation angle of the light source 2 with respect to the tile surface may be selected so that the shadow caused by the back legs is clearly detected by a visual sensor normally provided vertically above the conveyor belt 1. The illumination angle will generally range from about 10 degrees to about 70 degrees.

When a working tile surface is irradiated with light, if the tile surface is the back surface, a shadow of the light will be created due to irregularities such as the back legs on the back surface. That is, the enlarged longitudinal section of the tile shown in FIG. When the tile 10 passes directly under the visual sensor 3 due to light irradiation, only a bright part (front side) or a difference in brightness (back side) is generated, the visual sensor 3 detects the difference in brightness (difference in brightness) on the surface of the tile 10. Detects and determines whether it is front or back. If necessary, a front/back determination signal is sent to the control device, and based on the command from the control device, the tile determined to be front/back is reversed by the reversing machine 6 installed downstream of the visual sensor on the tile conveying belt. be able to.

Concrete example A specific example of the present invention will be described below with reference to the accompanying drawings.

In the apparatus of the present invention shown in FIG. 1, tiles 10 are conveyed in the direction of the arrow by a tile conveying belt 1. tile 1
When the tip 10a of the tile 1O blocks the light between the emitter 4a and the receiver 4b, the tile detection photoelectric switch connected to the receiver 4b is turned on, and the light emitted from the 60W light source 2 on the surface of the tile 1O is turned on. Detection of brightness difference starts. Visual sensor f- which is the camera part of Technosuf 1X (product name)
3 captures the difference in brightness on the surface of the tile 10 and sends a brightness signal to the digitization converter 7 of the Technosph 1X. The converting section 7 converts the bright/dark signal into a digital signal and sends the signal to the front/back determining section 8 . The determining unit 8 counts the digital signals from the converting unit 7 from the time when the tile 10 blocks the light beam between the light projector 4a and the light receiver 4b until the time when the tile 10 stops blocking the light beam.

A reference value is set in the determination unit 8, and the count value of the digital signal is compared with the reference value to determine whether the tile surface is front or back.

For example, four double-sided recesses 11a as shown in FIG.
When the back surface of the tile having ~lld'i passes directly under the visual sensor 3, the shadows of the recesses 11a to 11lid will sequentially pass directly under the visual sensor 3, so there will be four brightnesses due to the four shadows. The difference is captured by sensor 3.

The digital signal for one shadow is 1, and the digital signal count on the back side of the tile is 4. On the other hand, in the determination unit 8, the standard value is set to 3 for tiles of normal size (for example, dimensions 100 x 100 fields) having the back side shown in FIG. If it is less than 3, it is determined to be heads. This count value is theoretically O when the surface of the tile is on the upper side, but taking into consideration the case where brightness signals due to dirt etc. are counted, a count value up to 2 is determined to be the surface. Note that the above numerical values are not limited, and the reference values can be changed appropriately depending on the number and shape of unevenness on the tile surface.

The determination of whether the surface of the tile 10 is front or back is stored in the determination unit 8. When it is determined that the tile 100 side is the back side, a light projector 5a and a light receiver 5 installed near the entrance of the reversing machine 6 shown in FIG.
When it is detected by b that the tile 1o has been transported to a position near the entrance of the reversing machine 60, the reversing machine 6 is activated by a signal from the determination unit 8 to rotate the tile 10 by 1800 times.
Place the 1° tile face up.

A specific example of the reversing machine 6 is shown in FIG. When a signal for reversing the tile 10 is sent from the front/back determining unit 8, the air cylinder 13 is activated in time with the reversal timing photoelectric switch connected to the light receiver 5b, and the disc-shaped rotary plate 9 is rotated in the direction of the arrow. Push the rubber inner surface 9a of the rotating plates 9, 9'.

9a' is brought into contact with both sides of the tile 10. Rotating plate 9
．． 9' is a drive belt 12 while sandwiching the tile 10;
12' and rotates 180 degrees, so tile 10
is reversed by 1800 so that the surface is on the upper side.

After rotating 180°, the rotating plate 9 returns to its original position.

A specific example of the method of the present invention is shown in the processing block diagram in Figure 5. In FIG. 5, the visual sensor 3 detects tile 1.
A brightness difference of 0.10', 10'', etc. is detected, and the brightness/darkness signal is converted into a digital signal by the digitization conversion unit 7 and sent to the front/back determination unit 8.The tile determined to be front or back by the determination unit 8 10, 10', 10''... are shift registers 14
Then, the head and tail determinations are digitized into 0 (for example, heads) or 1 (for example, tails) and sent to the data selector 15. On the other hand, the detection signal of the presence or absence of a tile by the light emitting/receiving sections 4a and 4b is (g) a count signal, and the light emitting/receiving section 5a.

The tile carry-in detection signal to the reversing machine 6 by 5bK is (c)
The signals are collected as a count signal 6 and sent to the data selector 15 as a select signal.

Based on the digital signal (0 or l) of each tile collected in the data selector 15 and the selection signal, the air cylinder 13 is operated via the timing device 17 for the tile determined to be the back side, and the air cylinder 13 is activated to change the tile surface. Invert. As the visual sensor 3 and the digitization converter 7, for example, ■Technos product (Model 71X,) -
9 can be used.

Effects of the Invention According to the present invention, it is possible to automatically and efficiently determine the front and back sides of a tile having a gold main surface in bright and dark areas using oblique light.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a specific example of the device of the present invention;
The figure is a vertical cross-sectional view of a tile to explain the shadow caused by the back side of the tile; Figure 3 is a plan view showing the brightness and darkness of the back side of the tile with the back side; Figure 4 is a specific example of a reversing machine. and FIG. 5 is a processing block diagram of the method of the present invention.

Claims (2)

[Claims] (1) The tile surface that can be generated by light irradiation by irradiating light onto a tile surface moving in a certain direction at an angle of inclination with the surface and passing the tile surface under a visual sensor installed at a predetermined position. A method for detecting front and back sides of tiles with different surface conditions on the front and back, characterized by detecting a difference in brightness on the top and determining whether the tile surface is front or back based on the detected difference in brightness. (2) A tile conveyance belt, a light source for irradiating light at an oblique angle to the tile surface on the belt, and the irradiated moving tile installed at a predetermined position above the belt. A visual sensor for detecting the difference in brightness of a surface,
A tile front/back detection device comprising: a determiner for determining whether the tile surface is front/back based on the brightness difference detected by the visual sensor.