JPS61169749A - External surface inspection for article - Google Patents

Abstract

PURPOSE:To judge video information on a number of objects to be inspected introduced continuously with ease in comparison with a reference product information, by comparing video signals between the reference product and the object being inspected in real time. CONSTITUTION:An object A to be inspected is photographed to be converted into digital from analog and the video signal is applied to a comparison circuit 15. The comparison circuit 15 is made up of a real time comparison circuit 16 which compares the signal with a numeral of a reference product AS memorized into a memory circuit 12 and an allowable range comparison circuit 17. A specified pixel of the memory circuit 12 and a specified pixel of the video of the object A are made to coincide with a synchronous command circuit 18 with the pixel of a predetermined specified position as reference, then, both pixel signals are delivered sequentially synchronizing each other to be fed into a real time comparison circuit 16, which judges the difference (voltage difference) between both the signals and the results are applied into the next allowable range comparison circuit 17 to determine whether the difference is within the allowable range or not. The propriety of the signal (voltage) of each pixel is judged with the measuring range B of the video of the object A and when deficiency is found, a proper command is issued or a display lamp comes on.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates primarily to a method for inspecting the external surface of small articles such as tablets.

Conventional technology Conventionally, tablets are manufactured using a tablet press.

During penetration, visual inspection reveals electrical charges, cracks, and chips.

We perform inspections for printing stains, quality of engravings, etc.

However, people's intuitive judgment ability fluctuates depending on their physical condition and fatigue, and testing standards are not necessarily constant.

Moreover, it is inefficient and costly. As a means to improve this problem, a method of optical inspection using a TV camera or the like has been proposed. In this method, a standard product is photographed in advance with a TV camera, etc., image information of the surface is memorized, the specimen is then photographed under the same conditions, and the image information is compared with the above standard image information in a comparison circuit -ζ. , to judge the quality.

Problems to be Solved by the Invention In this case, a large number of tablets, etc. are continuously fed at high speed, and therefore, comparison and judgment must be carried out in a very short period of time. However, as an image sensor, for example, a CCD type solid-state image sensor (hereinafter referred to as C
When using a CD-type imager), the number of pixels (transfer electrodes) that make up the Wi surface is extremely large (for example, 5cIIx
Approximately on the Sell screen! 50,000 pieces) are arranged. Therefore, the memory circuit requires a corresponding number of memory elements, and the comparator circuit also requires a corresponding number of elements. Moreover, the comparison operation involves inputting the standard S@ information and sample image information into the above-mentioned numerous comparison elements and detecting the difference between them, which requires a considerable amount of time and effort until the first sample is sent. Even if you use a computer, it is extremely difficult to process the process within a short period of time.

One object of the present invention is to easily compare and judge the image information of a large number of specimens introduced in succession at high speed with the stored standard product information.

Means for Solving the Problems The present invention for achieving the above object will be explained based on FIGS. 1 to 4 corresponding to the embodiments.
is photographed by the imaging camera 4 (or S), and the video signal is A/D converted 111 and input to the recording circuit 12.

Next, the subject person is photographed, the resulting video signal is A/D converted, and the video signal is applied to the comparison circuit IFJ. This single circuit is equipped with a real-time comparison circuit 1G, and is characterized in that it compares the video signal of specimen A and the video signal of the standard product in real time.

Since both video signals are compared in real time,
Although each image is composed of a very large number of pixels, it is easy to compare them at high speed, and therefore it is possible to reliably measure articles (specimens) that are sequentially fed in at high speed.

EXAMPLE FIG. 1 The wooden example shown below shows an example in which the present invention is applied to the inspection of the outer surface of a tablet (hereinafter referred to as a specimen) sent out from a punching machine. No.! rg! The inspection machine 1 shown in J includes a pair of adsorption drums i! , II, and each suction drum 2.3 is provided with a recess for storing the specimen A to be measured and a standard tablet (hereinafter referred to as standard product) AS. After being sucked and stored, the specimen (or the specimen AS at 111) on the suction drum 2 is transferred to the suction drum 8 with its front and back turned upside down. An imaging camera 4.5 and a light source, for example, a strobe 6.1, which momentarily emits light are mounted on each suction drum 2.1. ), and the other camera 5FIL and strobe 1 are arranged to photograph the back side.

Camera 4. g allows for TV cameras etc.

Preferably, a camera using a CCD type solid-state image sensor is used. This CCD type camera is convenient for storing and retrieving image signals.

The procedures for determining the quality of the specimen A using the cameras 4 and 5 are the same, and the procedure for testing the specimen A using one of the cameras 4 will be described below.

FIG. 241 is a schematic process diagram of the inspection method of the present invention. First, take a picture of the surface of the standard product As with camera 4 as described above,
The video signal is stored in a temporary storage circuit 10 and applied to a measurement range calculation circuit 11. Generally, when taking pictures with a camera, s! The image waveform around the periphery of the quasi-product (including the specimen) is disturbed and distorted, so it is preferable to remove the capsule from the measurement range. Akira! There is a method of Imlm-1sat. This determines the center point of imaging.

A measurement range is set around this point and has a slightly smaller diameter than the outer circumference.

In Figure 1+, n indicates the measurement range. This measurement range B
The video signal (voltage) of each one element in the memory circuit 1! is memorized.

At the same time, a video signal is applied to the tolerance calculation circuit 1s, and the tolerance range of each pixel is set. This is to set a preset tolerance range (1! pressure difference), but 1!
1. There may be a slight deviation between the screen of S and the screen of the person being tested. In consideration of this, the maximum difference in voltage of each pixel within the range of the deviation is also taken into account for determination, and each of the one or more operations is performed using a computer.

Next, the sample person is photographed, A/D converted, and the image signal is applied to a comparison circuit 16. This comparison circuit 16 performs real-time comparison to compare the value of the drifting product As stored in the storage circuit 1. It consists of a circuit 16 and a tolerance comparison circuit 1f.

As mentioned above, the specimen A moves with a change in height and distance, and the measurement time interval between specimens is extremely short. Therefore, the comparison judgment process using a normal computer, that is, the stored information of each pixel in the storage circuit 12 is input to the elements of the comparison circuit, and , it is time-consuming to select a pixel at a corresponding position in the image of specimen A and input that information to the comparison element.

In addition, the number of pixels constituting both times is several hundreds of thousands of grams, as mentioned above, which requires a considerable amount of time and is inappropriate for high-speed processing.

Therefore, the invention of the tree is to perform this comparison in real time. This real-time processing refers to memory circuit 1! The information from the image data and the video information of the subject are synchronized and continuously fed out for the first time, and the difference is detected by performing the m-th judgment. That is, with reference to a pixel at a predetermined specific position, the memory circuit 1! The synchronization command circuit 18 matches the specific pixel of the image with the specific pixel of the image of the subject, and then both pixel signals are synchronized and sent sequentially to the real-time comparison circuit 16. (voltage difference) and primary tolerance comparison circuit 1
Apply to Ding.

A comparison is made to see if the difference is within an acceptable range.

This determines whether the signal (II pressure) of each pixel in the measurement range B of the image of the test KA is good or bad, and if it is bad, an appropriate command is issued or an indicator light is turned on.

Effects of the Invention As described above, the purpose of the invention is that the video signals of the drifting product and the specimen are compared in real time, so the comparison can be made at high speed. Therefore, it is extremely effective for inspecting the surface of mochi powder, etc., which is sent out at high speed from a hammer.

[Brief explanation of drawings]

FIG. 1 is a schematic process diagram of the external surface inspection method of the present invention. No.! The figure is a schematic explanatory diagram of the test, FIG. 8 is a plan view of a standard product and a specimen, and FIG. 4 is an explanatory diagram of real-time comparison processing. 4. Is is an imaging camera, ! Mushrooms are memory circuits. 1@ is the real-time comparison circuit, and the person is the sample. AS is a snow quality product. Patent issued: Odai, MutuTru Co., Ltd., etc.
1 person Figure 1 Figure 2

Claims (1)

[Claims] In an external surface inspection method in which a standard product and a specimen are each photographed and their surface conditions are compared to determine pass/fail, the standard product is photographed in advance using an imaging device, the standard video signal is A/D converted and input into a storage circuit, and then External surface inspection of an article, characterized by A/D converting a video signal obtained by photographing a specimen, and sequentially extracting the video signal and a standard video signal from the storage circuit in synchronization for comparison and judgment in real time. Method.