JPS61112948A - Method for inspecting product by television camera - Google Patents

Abstract

PURPOSE:To make it possible to accurately inspect a product without running an image at the time of the analysis of the image, by moving a television camera in parallel to a product in turning relation to the feed speed of the product. CONSTITUTION:The cylinder rod 5 of a cylinder 4 is fixed to the side surface of a television camera 3, and a slider and a rail 6 made freely slidable to said slider and having a recessed part 7 laterally provided to the upper part thereof are further arranged below the television camera 3 so as to be parallel to a first feed means 2. An image analyser 13 is connected to the television camera 3 and performs the image analysis of the video signal sent from the television camera and an electric signal is sent to a discharge apparatus 8 corresponding to the analytical result to protrude a rod 9. At the sliding time of the camera 3, the position, where products 1a, 1b... pass, is detected by a product detection apparatus 11 and the cylinder 4 is operated, after a time t1 was elapsed from the point of time when the product was passed, to protrude the cylinder rod 5 and the protruding speed thereof is made same to the moving speed of the feed means 2.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a product inspection device, particularly a blow bottle.

This invention relates to a method for inspecting containers such as glass bottles for scratches, foreign matter, and the quality of printed products, painted products, and other products.

Prior Art Conventionally, this type of inspection has been carried out with the naked eye, but if this inspection work lasts a long time, the operator's eyes will become tired.
This method has the drawback of increasing inspection errors, and there is also a limit to the throughput of visual inspection by humans, so high-speed inspection cannot be expected. Therefore, in view of the labor and inaccuracy of this visual inspection, the quality of the product is inspected using a TV camera that manually sends video signals from a TV camera placed opposite the product to an image analysis device. An inspection method has been proposed.

However, in order to get a good idea of the product using a TV camera, it was necessary to stop the image of the product shown on the TV camera for a certain period of time and analyze the image. Therefore, as a method to freeze the image for a certain period of time, technologies have been proposed that mechanically stop the movement of the product itself when it passes in front of the TV camera, or technologies that use strobes or mechanical shutters. ing.

Problems to be Solved by the Invention If the transfer of the product is mechanically stopped, the transfer method is extremely complicated and intermittent transfer at high speed is virtually impossible.

Furthermore, the method of using a strobe to optically stop the image of the product has the problem of malfunctions caused by the light from the robot, reducing inspection accuracy.Furthermore, the method of using a mechanical shutter to take pictures intermittently However, the structure of the television camera is complicated and expensive, and the durability of the television camera is also reduced.

Means and Effects for Solving the Problems The present invention has been made in view of the above-mentioned problems.It involves photographing a product moving at a constant speed with a television camera, and performing image analysis on the video signal obtained from the television camera. Regarding the inspection method of sorting products according to the electrical output obtained by processing, this method involves inspecting products with a television camera, in which the television camera moves parallel to the television camera in synchronization with the conveyance speed of the products.

In other words, in the present invention, the television camera is synchronized with the passing speed of the product and moved parallel to the product, so that the positional relationship between the television camera and the product remains relatively the same for a certain period of time, and the image of the product captured by the television camera is will essentially stop for a certain period of time.

Example The present invention will be described in detail below based on the drawings.

In FIG. 1, 1a, lb, . . . are products to be inspected, and in this embodiment, they are transparent round containers. The present invention inspects the side surfaces of the products 1a, lb, etc. for defects such as foreign matter, dirt, and deformation.

Reference numeral 2 denotes a first conveyance means, which conveys the products 1a, lb, . . . on this first conveyance means at a constant speed. 3
are arranged so that the sides of the products 1a, lb. are photographed with a television camera. A cylinder rod 5 of a cylinder 4 is fixed to the side surface perpendicular to the conveying direction of the first conveying means 2 of the television camera 3, and a slider (not shown) is attached to the lower part of the television camera 3. The rail 6, which is movable and has a concave portion 7 horizontally disposed on its upper part, transmits the second return motion to the television camera 3 without any difficulty, and the television camera 3 reciprocates quickly and without any positional shake. This television camera 3 includes an image analysis device 1
3 is connected to the TV camera 3, and the video signal sent from the TV camera 3 is image-analyzed, and according to the analysis result, a discharge device is provided at the side end of the first conveyance means 2 at a downstream position from the TV camera 3. An electrical signal is sent to 8. The discharge device 8 is
The image analysis device 1 has a cylinder rod 9 that can protrude in a direction perpendicular to the flow direction of the first conveyance means 2.
The rod 9 protrudes in response to a signal from 3. The above rod 9
It is removed from the first conveyance means 2, placed on the second conveyance means 10 moving in a direction perpendicular to the first conveyance means 2, and carried out by the flow of the second conveyance means 10.

When the television camera 3 slides, the product detection device 11 detects the positions through which the products 1a, lb, . . . pass. This product detection device 11 is located on the side of the first conveyance means 2 and upstream from the position of the television camera 3 in the flow direction of the product, and detects whether or not the product has passed by detecting optical changes. It is used to detect. After the product has passed and a certain time t1 has elapsed, the cylinder 4 is actuated so that the cylinder rod 5 protrudes. The protruding speed of the cylinder rod 5 is set to be the same as the moving speed of the first conveyance means 2, and the retracting speed of the rod 5 is set to be faster than that, so that the rod 5 can quickly return to the retracted position. To control this speed, a speed control valve (not shown) is provided at each discharge side port to adjust the displacement amount. By adjusting the discharge amount of cylinder 4 in this way, cylinder rod 9
The ejection speed can be precisely controlled,
The relative position between the television camera 3 and the product can be maintained reliably, and the protruding cylinder rod 9 will not cause any vibration. The above is a description of the apparatus according to the embodiment for carrying out the method of the present invention.

Next, the flow of the inspection method using these will be explained below. The products 1a, lb, . . . are transported at a constant speed by the first transport means 2. This is expressed as the slope of the straight line shown by the broken line on the graph shown in FIG. Here, to explain the flow of product 1d as an example, product 1d is
+II In front of the product detection device 11 (
When the light passes through point Δ in FIG. 2, it is sent to the analysis device 14 as an electrical signal.

After the product passes point A, the analyzer cylinder 4 is activated in advance. At this time, the position of the product 1d is at point B, and the position of the television camera 3 is from point B to the first conveying means 2.
It is located at the 0 point downstream of the point.

In other words, the product 1d that passed point A reaches 8 points after tl,
At that time, the cylinder 4 is at the zero point and starts operating. After the time t2 has passed since the cylinder started operating, the moving speed of the cylinder becomes equal to the transporting speed of the first conveying means, and at this position point, the product 1d and the television camera 3 are aligned on a straight line. The moving speed of TV camera 3 is product 1d
Since the moving speed is the same as that of , the relative positional relationship between the television camera 3 and the product 1d after passing the point D is maintained as it is when moving.

During t3 after passing point D, the television camera 3 moves while maintaining the positional relationship between the television camera 3 and the product 1d, starts to stop moving at point E, stops at point F, and then immediately Return the TV camera to point A. Next, when product 1d reaches point G, the next product 1e is located at point Δ, and is inspected in the same manner as 1d.

An image analysis device 13 analyzes the video signal taken when moving from point D to point E. In this analysis, for example, when using a photoelectric conversion method, if dirt or foreign matter is present on the surface of a product, it is captured as a shadow, outputted as an electrical signal, and the dirt or foreign matter is detected by changes in the electrical output. When a foreign object is detected in this way, and the foreign object is outside the allowable limit, the product detection device 15 measures the number of products passing through, and when the product 1d passes through the discharge device 8, the rod 9 is ejected. Then, the second conveying means 10 sends the sheets in a predetermined direction for sorting. TV camera 3 and product 1d
Since the time t3 during which the television camera 3 moves while maintaining its positional relationship with the video signal is a video signal that can be effectively used for image analysis, at least the scanning time of one screen of the television camera 3 is necessary. That is, t3 needs to be 16.7 milliseconds or more, and especially in the case of a mechanism that performs image analysis processing by pattern recognition, the scanning time for two screens, that is, 33.4 milliseconds or more is required.

Further, the time t1 manually set in the analysis device 14 is corrected within the circuit. In the above embodiments, the rising time t2 of the cylinder 4 changes each time.

The position of the television camera 3 and the product also shifts each time. Therefore, in the above embodiment, the image analysis device 13 detects this deviation, and feeds it back to the analysis device 14 to correct the setting of the time t and set it as tlo. .

As described above, in the above embodiment, the product 1 that moves at a constant speed
Located parallel to a, lb...
during which the television camera 3 is moved back and forth so that the relationship between the
This technology relates to the technology of sorting products according to the electrical output obtained by image analysis processing of video signals obtained from video signals, and is applicable not only to image analysis by photoelectric conversion but also to image analysis using a television camera such as image analysis by pattern recognition. It can be widely used, and if the positional relationship between the TV camera and the product shifts, the set time tl from when the shift between the product and the TV camera is detected until the cylinder operates.
By changing , the above positional relationship can be easily corrected.

Further, in the above embodiment, the position of the television camera 3 was set to the side of the product to photograph the side of the product, but the position of the television camera of the present invention is not limited to only the side; for example, from above. Alternatively, it is also possible to take a picture from below by any suitable means. Furthermore, it is also possible to organically analyze images by taking pictures with a plurality of television cameras. Further, in the above embodiment, an air cylinder was used as a means of moving the television camera, but the present invention is not limited thereto. For example, it is also possible to use a means of movement such as a hydraulic cylinder or a stepping motor. .

Further, the present invention can further increase inspection accuracy by using conventional optical image stopping methods such as the use of a strobe or a mechanical shutter.

Effects of the Invention As described above, the present invention provides a method in which a product moving at a constant speed is photographed by a television camera, and the video signal obtained from the television camera is image analyzed and inspected. Since it is moved parallel to the product in synchronization with the speed, the relative positional relationship between the TV camera and the product is fixed, and images do not flow during image analysis, allowing accurate inspection.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view showing an embodiment of the present invention. FIG. 2 is a partial plan view, and FIG. 3 is an explanatory diagram showing the flow of the product and the television camera.

Claims (1)

[Claims] Regarding a method of inspecting products with a TV camera, in which a product moving at a constant speed is photographed with a TV camera, and the video signal obtained from the TV camera is image-analyzed and the products are sorted according to the electrical output obtained. A method for inspecting a product using a television camera, which is characterized by moving parallel to the product in synchronization with the conveyance speed of the product.