JP2010266268A - Detection method of abnormalities in prints - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems wherein since prints of dates such as best-before-dates and expiration dates, and prints of numbers such as production numbers and lot numbers are inspected for a black print color which occupies 90% or more of commercial prints under a visible light environment, it is still insufficient to detect the abnormalities and failures of prints such as missing prints and fading prints, and wherein a wide variety of packaging materials, colors and shape of the shipped products, and the speeding up of automatic machines in manufacturing processes also bring about no detection of the abnormalities in prints. <P>SOLUTION: The detection of the abnormalities in prints is ensured by applying a light of a wavelength by which the most suitable contrast and luminance difference are obtained by specifying a wavelength band in which the difference of the reflectance and the difference of the transmission are maximum, a wavelength band similar thereto, or another effective wavelength band using inks such as blue, green, red and purple having spectroscopic characteristics different from black in the print color. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、賞味期限・消費期限などの日付の印字や製造番号・ロット番号などの印字が必要な製品の印字異常の検知方法に関するものである。   The present invention relates to a method for detecting an abnormal printing of a product that requires printing of a date such as a best before date or a expiration date, or printing of a manufacturing number or lot number.

製造業における出荷前の印字検査工程において、印字異常を検知する方法は二通り存在する。一つは目視による検知である。目視は人間の判断に左右され人それぞれの基準の差異があり、確実性に欠け、高速な工程においては目視で印字異常を検知することは困難である。二つめは画像による検知である。ＣＣＤカメラで印字部分を撮影し、画像センサーで瞬時に適正か否かの判断を行うものである。これは撮影された画像の電子データと適正な印刷用イメージデータを画像センサーで比較する方法で、印刷用イメージデータを構成しているドットと撮影された電子データのドットを比較することによって印字異常を検知する技術が提案されている。   There are two methods for detecting a printing abnormality in a printing inspection process before shipment in the manufacturing industry. One is visual detection. Visual inspection depends on human judgment and there is a difference in the standard of each person, lack of certainty, and it is difficult to visually detect a printing abnormality in a high-speed process. The second is image detection. A printed part is photographed with a CCD camera, and an image sensor instantly determines whether it is appropriate or not. This is a method of comparing the electronic data of the photographed image with the appropriate image data for printing with an image sensor. By comparing the dots constituting the image data for printing with the dots of the photographed electronic data, printing errors A technique for detecting this has been proposed.

特開２００３−０５４０９５JP 2003-054095 A

しかしながら、以上の技術は商業印刷で90％以上を占める黒色の印字色と可視光域の環境下での印字検査が行われており、依然として印字のもれやかすれなどの印字異常や不良を検知するには不十分である。また、出荷製品の包装の素材・色・形の多種多様化と製造工程の自動化機械の高速化も印字異常を検知しないまま見落としてしまう原因となっている。
そこで、この発明は、印字異常の検知精度を確実にする装置を提供することを課題とする。 However, the above technologies have been inspected for black print color, which accounts for over 90% of commercial printing, and in the visible light environment, and still detect print abnormalities and defects such as print leakage and fading. Not enough to In addition, the diversification of materials, colors, and shapes of packaging for shipped products and the speeding up of automated machines in the manufacturing process have also caused oversight without detecting print errors.
Accordingly, an object of the present invention is to provide an apparatus that ensures the accuracy of detecting a printing abnormality.

以上の課題を解決するために、第一発明は、印字色に黒色以外のインクの色、青、緑、赤、紫などを用いることである。その利点は分光上の特性があることである。黒色はほとんどの光の波長に対して反射せず吸収してしまうために黒として認識される。青、緑、赤、紫などは各々の色の光の波長を反射し、他の波長は吸収もしくは透過するという特性を持ち、それぞれの色として認識される。黒色以外の色を選択することにより印字色と背景色、つまり包装色との相関関係を作り出すことができる。
また、第二発明は、第一発明によって作り出した色の相関関係から最適な照射照明を設定することである。印字色と背景色の反射率もしくは透過率を測定し、二つ以上の色の相関関係から反射率の差、透過率の差が最大の波長帯もしくはそれに準ずる波長帯やその他の効果的な波長帯を特定し、その波長帯に絞った照射照明を設定する。 In order to solve the above problems, the first invention is to use a color of ink other than black, blue, green, red, purple, or the like as a print color. Its advantage is that it has spectroscopic properties. Black is recognized as black because it absorbs almost all light wavelengths without reflection. Blue, green, red, purple, and the like reflect the wavelength of light of each color and absorb or transmit other wavelengths, and are recognized as the respective colors. By selecting a color other than black, a correlation between the print color and the background color, that is, the packaging color can be created.
The second invention is to set the optimum illumination illumination from the color correlation created by the first invention. Measure the reflectance or transmittance of the print color and the background color, and based on the correlation between two or more colors, the difference in reflectance, the wavelength band where the difference in transmittance is the maximum or the equivalent wavelength band, and other effective wavelengths A band is specified, and irradiation illumination focused on that wavelength band is set.

第一発明、または第二発明によれば、設定した波長帯の照明を被検査物である出荷製品の印字部分のエリアに外光を遮断して照射すると、最適な明暗差・輝度差の状態がＣＣＤカメラで撮影でき、撮影した画像データを画像センサーに送ることができるため、画像処理の精度が上がり印字異常の検知を確実にすることが可能となる。   According to the first invention or the second invention, when the illumination of the set wavelength band is applied to the area of the printed part of the shipment product, which is the inspection object, while blocking the external light, the optimum brightness difference / brightness difference state Can be photographed with a CCD camera, and the photographed image data can be sent to the image sensor, so that the accuracy of image processing is increased and it is possible to reliably detect a printing abnormality.

図１は、この発明の一実施形態を示す側面図である。FIG. 1 is a side view showing an embodiment of the present invention.

この発明の一実施形態を、図１に示す。
波長帯を絞った照明１と３を被検査物である出荷製品５に照射する。この際の遮光板４と６で外光を遮断する。照射結果はＣＣＤカメラ２で撮影し、撮影した画像は画像センサーに送る。 One embodiment of the present invention is shown in FIG.
Illuminated products 1 and 3 having a narrow wavelength band are irradiated onto a shipment product 5 that is an inspection object. At this time, the light shielding plates 4 and 6 block external light. The irradiation result is photographed by the CCD camera 2 and the photographed image is sent to the image sensor.

さらに詳述すれば、出荷製品５はベルトコンベアなどから次々と搬送されてくる。ＣＣＤカメラ２の真下にきた時点で波長帯を絞った照明１と３を出荷製品５に照射する。４と６の遮光板で外光は遮断されているので、照射された波長帯の光は外光と混じることなく出荷製品５に直進し、印字部分の色を反射し、印字以外の部分は吸収もしくは透過する。反射した波長の色をＣＣＤカメラ２で撮影する。撮影した画像データは最適な明暗差・輝度差の状態であり、瞬時に画像センサーに送られる。
More specifically, the shipped products 5 are successively conveyed from a belt conveyor or the like. When it comes directly under the CCD camera 2, the shipping products 5 are irradiated with illuminations 1 and 3 with a narrowed wavelength band. Since the external light is blocked by the light shielding plates 4 and 6, the light in the irradiated wavelength band goes straight to the shipping product 5 without being mixed with the external light, reflects the color of the printed part, and other parts than the printed part Absorb or permeate. The color of the reflected wavelength is photographed by the CCD camera 2. The captured image data is in an optimal brightness / darkness / brightness difference state and is sent to the image sensor instantly.

この実施形態で取得し、画像センサーへ送る画像はＣＣＤカメラ２が白黒仕様の場合は、２５６階調のグレースケールで処理できる。しきい値補正などのコントラスト補正を施すことでより確実に検知処理ができる。ＣＣＤカメラ２がカラー仕様の場合、照射結果の印字色をあらかじめ測色して、ＲＧＢ値、ＣＭＹＫ値、ＸＹＺ値、ＬＡＢ値などの数値で登録し、近似色の範囲を設定しておけば、その数値範囲の色にコントラスト補正等の処理を施すことにより検知の精度が上がる。また、印字以外の背景色をあらかじめ測色して前述同様に処理すれば、その数値範囲を白色などの色に一括変換することにより、印字部分との対比が顕著になり検知処理の精度が上がる。   The image acquired in this embodiment and sent to the image sensor can be processed with a gray scale of 256 gradations when the CCD camera 2 is in monochrome. Detection processing can be performed more reliably by performing contrast correction such as threshold correction. If the CCD camera 2 is of color specification, the print color of the irradiation result is measured in advance, registered as numerical values such as RGB values, CMYK values, XYZ values, and LAB values, and an approximate color range is set. By performing processing such as contrast correction on the color in the numerical range, the detection accuracy is improved. If the background color other than printing is measured in advance and processed in the same manner as described above, the numerical range is converted into a color such as white at the same time, so that the contrast with the printed portion becomes conspicuous and the accuracy of the detection processing increases. .

出荷製品５の包装色が透明色の場合は、ＣＣＤカメラ２を５の真下に設置する。この場合、印字色と包装色の透過率で設定された照射照明１と３を照射しＣＣＤカメラ２で撮影すると同様の結果が得られる。   When the packaging color of the shipping product 5 is a transparent color, the CCD camera 2 is installed directly below 5. In this case, the same result can be obtained by irradiating the illumination lights 1 and 3 set by the transmissivity of the printing color and the packaging color and photographing with the CCD camera 2.

１ 照射照明
２ ＣＣＤカメラ
３ 照射照明
４ 遮光板
５ 出荷製品
６ 遮光板 DESCRIPTION OF SYMBOLS 1 Irradiation illumination 2 CCD camera 3 Irradiation illumination 4 Shading board 5 Shipment product 6 Shading board

Claims (2)

賞味期限・消費期限などの日付の印字や製造番号・ロット番号などの印字色に黒色以外の分光上の特性がある青、緑、赤、紫などのインクを用いて、その特性に応じた波長の照明を照射して印字異常を検知する装置。   Wavelengths according to the characteristics of inks such as blue, green, red, and purple, which have spectral characteristics other than black, such as printing of dates such as expiration dates and expiration dates, and printing colors such as production numbers and lot numbers. A device that detects printing errors by illuminating 請求項１において、印字色と包装色との間の反射率の差、透過率の差が最大の波長帯もしくはそれに準ずる波長帯やその他の効果的な波長帯を特定することにより最適な明暗差・輝度差の状態を作成して印字異常を検知する装置。
The optimum light and dark difference according to claim 1 by specifying a wavelength band in which the difference in reflectance and transmittance between the printing color and the packaging color is maximum, a wavelength band equivalent thereto, or other effective wavelength band. -A device that creates a brightness difference state and detects printing errors.