JPS6239700B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for inspecting foreign matter or color change that has adhered to or mixed into industrial products, medicines, foods, etc., and in particular, detects the presence or absence of foreign matter by detecting the contrast with the foreign matter. This is how it was done.

This type of inspection in the production process includes visual inspection, and observation using a monitor equipped with a television camera. The latter example is a method used when visual inspection is not possible during the manufacturing process, but is essentially the same as visual inspection.

However, these inspection methods have the disadvantage that they require a lot of labor, that individual differences appear in the judgment criteria, and that the quality tends to vary.

Therefore, an object of the present invention is to provide an inspection method that requires less labor and does not cause variations in quality.

In order to achieve this object, the present invention photographs the object to be inspected with a television camera, detects any portion of this video signal that exceeds or falls short of a reference value, and A signal for quality determination is obtained.

The method of the present invention will be explained in detail below.

In Figure 1, 1 is an input terminal (not shown) that receives a composite video signal from a television camera that photographs the object to be inspected. For example, a composite video signal of a uniform level corresponding to the color is supplied, and if colored deposits or contaminants are present, a part of the signal level is supplied with a change.

Reference numeral 2 denotes a buffer amplification section, which has the effect of amplifying the composite video signal supplied to the input terminal 1. Reference numeral 3 denotes a comparison section which has the function of comparing the composite video signal level from the input terminal 1 with a reference level. The reference level set by the comparison section 3 is made to match the color tone of the object to be inspected, which is considered to be rejected, for example, due to deposits, and if the object to be inspected has colored deposits or contaminants, the standard level is A signal higher than the level or, conversely, lower than the level is supplied to the polarity selection section 5 at the next stage. The comparison section 3 is composed of a reference voltage generation section 4b that obtains a reference level, and a sensitivity adjustment section 4a that can arbitrarily adjust the reference level in accordance with the composite video signal of the object to be inspected.

The polarity selection section 5 obtains a signal exceeding the reference level and a signal below the reference level from the comparison section 3, and has the operation of selecting one of them. This selection is made depending on the color tone of the object to be inspected. If the color tone is bright and the deposits or contaminants are dark, select a signal that does not meet the standard level, and if the opposite is true, select a signal that exceeds the standard level. It is something to do.

Reference numeral 6 denotes a pause time control section, which has the function of removing a portion of the composite video signal supplied to the input terminal 1 other than the video signal. The purpose of this is to facilitate subsequent operations by removing unnecessary signal components.

Reference numeral 7 denotes a logic section, which is constituted by an AND circuit and has the function of sending out the logical output of the output of the polarity selection section 5 and the output of the pause time control section 6.

8 is a buffer amplification section, and 9 is a mixing section, which connects the output of the logic section 7 amplified by the buffer amplification section 8 and the input terminal 1.
and a composite video signal amplified by the buffer amplification section 2, and the output thereof is supplied to an output terminal 11 for a monitor television, not shown in the figure. Note that in the displayed image, if there is a different colored deposit or contaminant in the object to be inspected, that part will be displayed as a bright spot.

Reference numeral 10 denotes a storage section which has the function of storing the output of the logic section 7 amplified by the buffer amplification section 8. This stored content is output to the output terminal 12 and used as a signal for determining the quality of the inspected object.

Next, the operation will be explained with reference to the time chart shown in FIG. 1a is a composite video signal sent out from a television camera and supplied to input terminal 1, 3L is a reference level set by comparator 3, and this figure shows brightness in the video signal that exceeds reference level 3L. A portion 1H and a portion 1L smaller than this are shown. In other words, the color tone of the object to be inspected is not uniform;
Different colors indicate the presence of deposits and contaminants.

This composite video signal 1a is supplied to a mixing section 9 via a buffer amplification section 2, and is also supplied to a comparison section 3 and a pause time control section 6, where it is combined with a signal below the reference level 3L. A signal that exceeds the threshold is detected. 3a is the output of the comparator 3, the bright part of the object to be inspected is at H level, and the dark part is at L level.
level and is supplied to the polarity selection section 5.

5a and 5b are the outputs of the polarity selection section 5, of which 5a is a non-inverted output that is the output of the comparison section 3 as it is.In this case, the part of the object to be inspected that is brighter than the reference level becomes a white bright spot on the monitor TV. On the other hand, 5b is an output obtained by inverting the output of the comparing section 3, and even in this case, a portion of the object to be inspected that is darker than the reference level will appear as a white bright spot. The reason for this is that the portion 1L, which does not meet the reference level, is set to H level by the reversal operation. The details of the white bright spot appearing on the monitor TV will be explained later.

Outputs 5a, 5 selected by polarity selection section 5
b is supplied to the logic unit 7, where the logic output 7a is connected to the output 6a of the pause time control unit 6.
Or get 7b. Note that the output 7a is a case where the polarity selection section 5 selects a non-inverted output, and the output 7b is a case where an inverted output is selected.

The logic output 7a or 7b is then supplied to a mixing section 9 via a buffer amplification section 8, where it is mixed with the composite video signal 1a and supplied to an output terminal 11. 9a is the mixing section output when the logic output 7a is supplied to the mixing section 9, and 9b is the mixing section output when the logic output 7b is supplied.

What is important here is that the mixing section output 9a,
9b is that even if the signal level does not reach the reference level 3L set by the comparator 3, or the signal level exceeds it, the signal level is sent out at a higher signal level. Deposits or contaminants of different colors present on the object to be inspected are displayed as white bright spots on the monitor television, making the confirmation work easier.

On the other hand, in the storage unit 10, when the logic output 7a or 7b is received, the outputs 10a and 10b are held at H level in any case, so that it is possible to detect deposits or contaminants of different colors on the object to be inspected. The presence is stored and can be used, for example, as a signal for determining the quality of the inspected object.

The above explanation is based on the assumption that the object to be inspected has deposits or contaminants of different colors.If the object to be inspected is normal, the polarity selection unit 5 selects which side. Even if the logic part 7
There is no output, and there are no white bright spots on the TV monitor screen. In addition, the storage unit 10
The output is at L level.

As is clear from the above explanation, the first invention is such that when there is a deposit or contaminant with a different color tone on the object to be inspected, this portion appears as a white bright spot. Because of this, it becomes clear at a glance whether the object to be inspected is good or bad, which has the effect of making inspection work easier. Note that even if there is a dark area on the object to be inspected due to foreign matter, it will appear as a white bright spot, making it easy to inspect paper for dirt or damage.
It is effective for detecting contaminants in foods, granular or powdered medicines, etc.

In addition, the second invention is such that when there is a deposit or a contaminant with a different color tone on the object to be inspected, the presence is detected and stored.
For example, it can be used as a signal source to automate the inspection of the object to be inspected and to obtain a display or alarm sound when an object is detected, making it possible to automate the inspection of whether the object is good or not. have an effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the inspection method according to the present invention, and FIG. 2 is a time chart of each part in FIG. DESCRIPTION OF SYMBOLS 1... Input terminal, 2... Buffer amplification section, 3... Comparison section, 5... Polarity selection section, 6... Pause time control section, 7... Logic section, 8... Buffer amplification section, 9 ...Mixing section, 10...Storage section.

Claims (1)

[Claims] 1 Compare the composite image signal obtained by photographing the inspected object with a reference level set in advance according to the color tone of deposits or contaminants on the inspected object, and determine whether the signal exceeds the reference level or the signal does not exceed the reference level. If a signal that exceeds the standard level is extracted, it is left as is; if a signal that is less than this level is extracted, it is inverted, and in addition to the composite image signal, the color tones attached to or mixed in the object to be inspected are extracted. A method for inspecting deposits or contaminants with different tones, which is characterized by displaying different foreign substances as white bright spots on a monitor.