JP4714847B2 - Ink supply monitoring device - Google Patents

Description

  The present invention relates to an ink supply monitoring device and an ink supply monitoring method for continuously inspecting the characteristics of ink to be supplied in a non-contact manner in a printing machine to which ink having invisible characteristics is supplied.

  In recent years, due to remarkable development of color copiers and computers, many cases of counterfeiting such as various securities and valuable printed matter have occurred. From such a tendency, it is a common practice to use ink having invisible characteristics as one of the means for preventing forgery in printing various securities and valuable printed matter.

  As inks having invisible characteristics, generally known techniques include infrared inks characterized by spectral reflectance in the infrared region, fluorescent light-emitting inks that emit light when irradiated with ultraviolet light, and magnetic properties by adding materials that contain magnetism. There are magnetic inks characterized by having a DNA ink and DNA inks containing DNA for authenticity determination.

  As a method for inspecting a printed matter using ink having invisible characteristics, a printed matter inspecting method for detecting the magnetic quantity possessed by the ink and its apparatus (for example, see Patent Document 1) have been proposed. As an ink with invisible characteristics, for example, an ink containing magnetism and an ink not containing magnetism are used, and the design is divided into two parts and printed, with one design having magnetism and the other design having magnetism. As a print portion that does not have, it is confirmed by scanning the surface of the printed matter with a measuring device having a magnetic detection head, and an invisible function is guaranteed.

  Infrared inks include inks that have reflection characteristics in the infrared region and inks that have absorption properties. Using these ink properties, inks that exhibit the same color in the visible light region and have reflection properties in the infrared region There are inks that use a pair of inks having absorption characteristics (hereinafter referred to as “infrared reflection absorption pair inks”).

  As for the composition of anti-counterfeit printed matter with infrared reflection absorbing pair ink, generally one design is divided into two printing parts, one is printed with ink that reflects infrared light and the other is printed with ink that absorbs infrared light. Has been. Since the two inks appear to be the same color in the visible light region, they appear to be printed with one ink to the naked eye.

  In addition, security printed matter using infrared absorbing ink does not use any special material, there is no restriction on the color of the visible image to be formed, it has excellent concealment of the image pattern formed by infrared absorption, infrared pattern There is an infrared absorbing printed matter (see, for example, Patent Document 2) that does not require the formation of a white-based concealing printing layer even when forming a color image. In this printed matter, one design is divided into two printing areas, one of which is printed with an ink of an infrared transmitting ink and the other is an ink of an infrared absorbing ink (hereinafter referred to as “infrared transmitting and absorbing pair ink”). If the infrared transmitting / absorbing pair ink is the same color (small color difference) in the visible light region, it will appear as one pattern to the naked eye.

  When a printed matter with such a design is viewed using an infrared camera that can convert infrared light into visible light and can be seen, only the portion printed with ink that absorbs infrared light is visible. It can be seen that the portion printed with ink that reflects or transmits light has disappeared. In the infrared camera, an infrared light source and a light receiving unit are configured by a CCD camera or a photodiode, and are used as a general device for checking the quality of printed matter using infrared ink.

  In addition, in the printing process or inspection process of printed matter using two or more kinds of inks having different spectral characteristics in the infrared region, an infrared sensor is mounted above the printing machine etc., and printed sheets of securities printing products The printed surface inspection apparatus converts the infrared reflected light of the printed product into visible light to obtain image data, and inspects the printed product by comparison with reference image data recorded in advance (see, for example, Patent Document 3). .) Has been proposed.

  Further, in a printing machine that supplies ink using magnetism in invisible characteristics, an ink characteristic detection element is provided in an ink fountain of the printing machine, and a method for online inspection of magnetic characteristics of security ink having invisible characteristics and An apparatus (see, for example, Patent Document 4) has been proposed. During printing, a change in magnetism is detected and anomalies are detected when the magnetic properties of the magnetic ink are deficient or diluted due to an incorrect ink supply, or when magnetic ink is mixed with ink that does not contain magnetism.

JP 2001-1506 A Japanese Patent Laid-Open No. 10-244747 JP-A-10-337935 JP-T-2004-507378

  According to Japanese Patent Laid-Open No. 2004-26883, one magnetic design is divided into two print areas, and the amount of magnetism held by the ink is detected from a printed matter having a design that is printed with ink having magnetism on one side and ink not containing magnetism on the other. By comparing with the magnetic measurement result of a normal printed matter, an ink supply error can be found. However, since it is an off-line sampling inspection, it is difficult to inspect the entire printed matter and it is inefficient because it takes time.

In addition, in the production of printed matter using infrared transmission / absorption paired ink according to Patent Document 2, if a mistake occurs at the ink supply stage, even if it cannot be detected by online visual inspection, it disappears from the region visible with the infrared camera. Ink supply errors can be found because the area is different from the normal product image.
However, the off-line inspection using an infrared camera or the like is a sampling inspection of the printed material, so that it is difficult to inspect the entire amount of the printed material, and the measurement takes time, which is inefficient.

  As described in detail above, the method of inspecting a sampled printed matter, which is a conventional off-line inspection method, takes a long time to find an ink supply error even if a supply error occurs due to an incorrect ink insertion. There were many problems that occurred. In order to recover the invisible function, it is necessary to clean the printing press and replace the ink. In addition, because it is a non-continuous off-line inspection, when sampling is performed during printing, sampling is not performed at the timing when an ink supply error is committed, and if sampling is performed after the ink has been supplied correctly, There was a problem that an abnormal product that lost the usefulness of the invisible function printed on was not found.

Therefore, an inspection apparatus according to Patent Document 3 has been proposed, and sampling is not performed at the timing when an ink supply error is made, which is one of the problems of offline inspection, by online inspection of the entire amount of printed matter on a printing press. This solves the problem of overlooking the occurrence of abnormal products that have lost the usefulness of the invisible function when the ink is sampled after the correct ink supply.
However, since this method is also an inspection of printed products, the discovery is slow even if an ink supply error occurs, and if an abnormality is detected, there is a problem that many abnormal products that have already been printed have occurred. It was.

Further, as another method for inspecting the entire amount of printed matter online without taking time for sampling, an inspection apparatus and an inspection method according to Patent Document 4 have been proposed.
This method also does not sample at the timing when an ink supply error is committed, which is one of the problems of off-line inspection. Solves the problem of missing outbreaks.

  However, since the magnetic characteristic detection element is immersed in the ink in the ink fountain, the apparatus of Patent Document 4 has a complicated structure such as an integrated structure of the ink stirrer provided in the ink fountain and the magnetic characteristic detection element. Installation and maintenance on the printing press are complicated. When the inspection object is high-viscosity ink, there is a concern that the magnetic property detection element is clogged and the detection sensitivity is lowered. In addition, in order to produce a normal printed matter when an abnormality due to an ink supply error is detected, in addition to cleaning the ink fountain, the magnetic property detection element to which the ink that has been supplied incorrectly does not have to be cleaned. However, there is a problem that the work load is larger than that of the non-contact type inspection method.

  Therefore, in the present invention, instead of an off-line inspection after printing, in the ink supply stage, which is a pre-printing stage, the ink inside the inker is inspected on-line and further in a non-contact manner, so that early detection of an error in ink placement can be achieved. It is an object of the present invention to provide an ink supply monitoring device and a monitoring method for reducing a cleaning work load after an error in ink insertion or preventing an error in ink insertion.

  The ink supply monitoring device of the present invention is a monitoring device for continuously and non-contactly inspecting the characteristics of ink having invisible characteristics supplied to a printing press, and the ink having invisible characteristics supplied to a printing press. The inspection unit that continuously inspects the characteristics of the ink, the control unit that compares the measured value of the ink that was inspected by the inspection unit with the measurement reference range that is stored in advance, and the determination result in the control unit It consists of a display alarm section to inform the person.

  The inspection unit of the ink supply monitoring apparatus of the present invention has an irradiation means for irradiating a specific light source suitable for the invisible characteristic and an invisible characteristic irradiated with the specific light source for the ink having the invisible characteristic supplied to the printing press. It comprises light receiving means for receiving reflected light from the ink it has.

  The inspection unit of the ink supply monitoring device of the present invention has at least a corresponding characteristic for each of the characteristics of the ink supplied to the printing press, or each of the areas where the ink is supplied when the ink having the same characteristics is supplied to a plurality of positions. It consists of arranging one inspection part.

  The control unit of the ink supply monitoring device of the present invention provides a reference range and a determination result set based on a measurement value obtained by the inspection unit when ink having invisible characteristics is normally supplied, and relationship information at the time of determination. A storage unit for storing, a determination unit for comparing the reference range stored in the storage unit with the measured value of the invisible characteristic ink supplied to the printing press, and determining whether or not it is within a preset reference range; Command means for stopping the printing press when the judgment result by the means is defective is provided.

  The display alarm unit of the ink supply monitoring apparatus of the present invention includes a display unit that displays a determination result determined by the control unit and / or related information at the time of determination, and an alarm unit that issues an alarm.

  The invisible characteristic ink used in the ink supply monitoring apparatus of the present invention is an infrared ink having different spectral characteristics in the infrared region, and the irradiation unit has a specific light source to be irradiated with infrared light.

  The ink supply monitoring method of the present invention is a monitoring method for continuously and non-contactly inspecting the characteristics of ink having invisible characteristics supplied to a printing press, and is a specific light source adapted to the characteristics of the target ink. By irradiating the ink, receiving the reflected light from the ink, determining whether the amount of received light is within the normal reference range stored in advance, and transmitting the determination result to the operator This is an ink supply monitoring method.

  The ink supply monitoring method of the present invention is characterized by irradiating a specific light source, receiving reflected light, and making a determination for each ink characteristic or when ink having the same characteristic is supplied to a plurality of parts. And

  The ink supply monitoring method of the present invention is characterized by issuing a stop command to the printing press when the determination result is defective.

  The ink supply monitoring method of the present invention is characterized by issuing a display and / or an alarm in order to transmit a determination result to an operator.

As described above, in the ink supply monitoring apparatus of the present invention, even if there is an ink supply mistake during printing that cannot be confirmed with the naked eye under visible light, the ink characteristics inside the inker are not determined by sampling inspection of the printed matter. It is possible to quickly find by online inspection, and it is possible to minimize the amount of abnormal products generated without the usefulness of the invisible function. In addition, since it is an on-line inspection, unlike the sampling inspection of printed matter, it is possible to inspect the ink characteristics of all the printed products.

  Compared with the method of detecting an ink supply error using a contact sensor as described in Patent Document 4, the ink supply monitoring device of the present invention is a non-contact type, so that the sensitivity due to the contamination of the detection portion is reduced. There is no reduction, and it is possible to select an arbitrary mounting position that can irradiate the ink to be inspected with a specific light source, and the structure is simple, which is convenient for maintenance.

  When the ink supply monitoring device of the present invention is installed in the apparatus for supplying ink to the inker unit in a different form from the installation of the ink supply monitoring device of the present invention in the inker unit of the printing press, the ink supply Since errors can be detected not only during printing but also in the ink supply stage before the start of printing, it is possible to prevent the occurrence of abnormal products that have lost the usefulness of the invisible function.

  As a printing machine equipped with the ink supply monitoring apparatus of the present invention, any machine can be used as long as the invisible characteristic ink that can be detected by the inspection unit of the present invention is used. For example, at least two types of ink containing at least invisible characteristic ink, such as an ink manufacturing apparatus that produces invisible characteristic ink, an apparatus that packs invisible characteristic ink in a container, and a transport apparatus that transports a container containing the manufactured invisible characteristic ink Applicable to all cases such as use.

  As shown in FIG. 1, the ink supply monitoring apparatus of the present invention includes an irradiation unit that irradiates a specific light source suitable for the invisible characteristics of the ink to the ink supplied to the printing press, and an invisible light that is irradiated with the specific light source. An inspection unit 1 having a light receiving means for receiving reflected light from ink having characteristics, a determination means for determining whether or not a reference range stored in advance in a storage means, and a determination result is a reference value The control unit 2 is provided with a command unit for stopping the printing press when it exceeds the limit, and the display alarm unit 3 is provided with a display unit for displaying a determination result in the control unit 2 and an alarm unit for issuing an alarm. ing.

  In addition, when the determination result exceeds the reference range, the display alarm unit stores the related information such as the detection location, the measured value, the production lot number, the determination date and time in the storage unit, so call these information, It has a function to display. These functions can be used to search for abnormal products when the target abnormal products and normal products are mistakenly mixed, or when the printing press stop means do not work for some reason, This is effective when it is necessary to investigate an ink supply error later, such as when an operator has overlooked.

  As the irradiation means of the inspection unit, an infrared sensor is considered when the target characteristic is an infrared characteristic, a non-contact type magnetic detection sensor when the characteristic is magnetic, and an ultraviolet sensor when the characteristic is fluorescent. However, the present invention is not limited to this, and any detection tool capable of appropriately detecting each characteristic may be used.

An ink supply monitoring method for inspecting the characteristics of ink having invisible characteristics supplied to a printing machine continuously and in a non-contact manner and finding an ink supply error will be described in detail with reference to the flowchart of FIG.
When the on-line inspection is started (S1), the irradiation unit starts irradiation of a specific light source suitable for invisible characteristics (S2), and the reflected light is received by the light receiving unit (S3). A signal in which the amount of light received by the light receiving means is digitized is transmitted to the determining means, and compared with a reference range set in advance in the storage means, and correct / incorrect determination is made (S4). As a result of the determination, if it is within the reference range, the inspection is continued. If it exceeds the reference range, it is determined that an abnormality has been detected, an abnormality display, an alarm is transmitted, and a printing press stop signal is transmitted (S5). ). If it is determined to be defective, the history of the detected location, measurement value, date of occurrence, etc. is recorded in the storage means as related information (S6). This history can be displayed on the display means or written out by an output device (not shown).

  The ink supply monitoring apparatus of the present invention will be described in detail using a printing machine using a highly viscous infrared transmitting and absorbing pair ink as an example, and an intaglio printing machine equipped with the ink supply monitoring apparatus used in that case Will be described.

  FIG. 4 shows a configuration example of an intaglio printing machine equipped with the ink supply monitoring device of this embodiment.

  The printing unit of the intaglio printing press includes a plate cylinder 6, an impression cylinder 7, a wiping roller 8, a filling roller 9, an ink discharge roller 5, and an ink fountain 10. In the case of an intaglio printing machine, when intaglio ink is supplied to the ink fountain 10, the ink is transferred from the ink discharge roller 5 to the fleshing roller 9, and the ink transferred to the plate surface of the plate cylinder 6 is transferred to the excess ink by the winding roller 8. Is scraped off and then printed on a sheet passing between the plate cylinder 6 and the impression cylinder 7. The area around the ink fountain and the ink discharge roller is particularly called the inker part. Since the structure of the inker portion is substantially the same for an offset printing machine other than the intaglio ink, the printing machine to which the ink supply monitoring device of the present invention is attached is not limited to the intaglio printing machine.

Example 1
FIG. 3 shows an embodiment of the ink supply monitoring apparatus of the present invention. In the present embodiment, the inspection unit 1 is arranged above the inker unit ink discharge roller of the printing press, and connected to the control unit 2 and the display alarm unit 3, so that the ink on the surface of the ink discharge roller 5 of the inker unit 4 can be inspected online. It is comprised as follows.

The inspection unit 1 is an infrared sensor including an infrared light source such as an infrared LED (not shown) or an infrared semiconductor laser, and an infrared photodiode that receives infrared light reflected from the ink on the roller surface. A signal is transmitted to the control unit 2. Such an infrared sensor is mainly composed of an infrared light irradiation part and a light receiving part, and is less expensive than a CCD camera described later.
The infrared sensor irradiates infrared light perpendicularly to the ink surface and receives regular reflection light, so that the measurement tends to become unstable due to the gloss of the surface coating of the ink. It is preferable to install the inspection unit 1 so as to irradiate and receive light from an oblique side.

The inspection unit 1 must arrange at least one for each kind of ink to be inspected, so-called different characteristics or each ink supply location.
When two types of infrared reflection / absorption pair inks are used in one printer, it is necessary to place at least one inspection section in the inker section containing each ink. Yes, as a method of dividing the pattern of the printed matter, as shown in the example of FIG. 5, when one inker part is divided into four places, if two or more types of ink are used, the divided four places Since the ink must be supplied without error, it is necessary for the inspection unit 1 to arrange at least one inspection unit for at least one ink supply unit, for a total of four or more.

In the case of the ink supply monitoring apparatus shown in FIG. 3, since the infrared sensor scans only a part of a narrow area on the surface of the ink discharge roller, if there is an ink supply error outside the scanning area, the scanning area It will not be detected until the misfeed ink has diffused and entered.
In particular, if the ink used is a highly viscous intaglio ink and an ink supply error is made outside the scanning area, the ink supplied into the ink fountain diffuses from the supply area until it adheres to the surface of the ink ejection roller in the scanning area. Therefore, when the ink supply position is away from the inspection area of the inspection unit 1, it takes time to detect.
In this embodiment, the inspection section is not limited to one place for one inspection object. For example, when the range where ink is expected to be input is wide, a plurality of places on the surface of the ink discharge roller are provided. It is preferable to arrange the infrared sensor so as to scan.

In order to obtain a good discrimination capability by the ink supply monitoring device, it is desirable to use a material that does not affect the invisible ink used by the roller material when the characteristic is measured by the inspection unit.
For example, when detecting an ink supply mistake of the infrared transmission / absorption pair ink, since the infrared transmission ink transmits infrared rays, it is desirable that the base of the infrared transmission ink has infrared reflection characteristics. When the ink base has infrared reflection characteristics, the infrared transmission ink reflects infrared light due to the influence of the base, and the infrared absorption ink absorbs infrared light without the influence of the base. However, when the ink base is a member with infrared absorption characteristics, the infrared transmission ink absorbs infrared light due to the influence of the base and is difficult to distinguish from the infrared absorbing ink. . Therefore, in order to obtain a good discrimination capability, it is desirable that the surface of the ink discharge roller is made of a material having infrared reflection characteristics.

  The arrangement position of the inspection unit 1 constituting the ink supply monitoring apparatus described in the present embodiment is not limited to the upper part of the ink discharge roller, but is arranged at a position where the ink can be irradiated with infrared light and reflected light can be received. Just do it.

In the present embodiment, since the infrared transmission / absorption pair ink is used, the correct / incorrect determination is made in the inker portion using the infrared transmission ink and the inker portion using the infrared absorption ink. The
In the inspection part 1 of the inker part to which the infrared transmission ink is supplied, a reference value is set from the value obtained when the ink is supplied normally, and a low measurement value is detected if the infrared absorption ink is supplied by mistake. Then, it is determined that the controller is erroneously input, and is transmitted to the display alarm unit.
In the inspection part 1 of the inker part to which the infrared absorption ink is supplied, when the infrared transmission ink is supplied by mistake, a value higher than the reference value set from the value obtained when it is supplied normally is detected. Therefore, the control unit determines that it is erroneously input and transmits it to the display alarm unit.

  When it is determined that the control unit is defective, it is possible to store a determination history such as a detected part of the defect, a measured value at the time of the defect determination, a product lot number at the time of the defect determination, a defect determination date and time, and the like. The determination history stored in the control unit can be displayed in the display alarm unit, and even if the operator is not aware of the alarm at the time of defect determination, the abnormal product can be easily searched for at a later date.

(Example 2)
FIG. 6 shows another embodiment of the ink supply monitoring apparatus of the present invention. The inspection unit 1 of the ink supply monitoring apparatus of Example 1 is a CCD camera system.

  In this embodiment, a CCD camera 11 and an infrared light source 12 are arranged above an inker part ink ejection roller of a printing press, connected to a control unit 2 and a display alarm unit 3, and ink on the upper surface of the ink ejection roller 5 of the inker unit 4. Is configured so that it can be inspected online.

  When the CCD camera 6 is disposed, the ink on the surface of the ink discharge roller 5 is spread over a wide range by disposing it above the ink discharge roller 5 so that the lateral direction with respect to the rotation direction of the ink discharge roller 5 is detected in a wide range. Can be inspected. The entire surface of the ink discharge roller 5 may be inspected by one camera, or the entire surface of the ink discharge roller 5 may be inspected by arranging a plurality of CCD cameras 6. At this time, it is preferable that the infrared light source 7 is irradiated obliquely from the side for the same reason as in the first embodiment.

  As an ink supply judgment method, an image received through a filter or the like is binarized with infrared reflected light and infrared absorbed light so that only infrared light can be received, and is obtained when ink is properly supplied to the inker unit 4. In the control unit 2 that stores the obtained value as a reference value in advance, the reference value and the measured value are compared, and when it is determined that the value exceeds a certain reference value, an abnormality display or a warning may be issued.

  As another determination method, there is a method in which the control unit directly compares the image obtained when the ink is normally supplied to the inker unit 4 stored in advance and the received image data, or the infrared of the inker unit There is also a method of displaying images on a monitor and visually checking them.

(Example 3)
FIG. 7 shows another embodiment of the ink supply monitoring apparatus of the present invention. The inspection unit 1 of the ink supply monitoring device is arranged in an ink transparent container set in the automatic ink supply device.

  In this embodiment, the inspection unit 1 is disposed at a position where the ink can be irradiated with infrared light from the surface of the transparent ink container, and connected to the control unit 2 and the display alarm unit 3. The ink is configured to be inspected.

  When supplying ink to a printing machine that uses ink with low viscosity, the remaining amount of ink in the inker is detected by a sensor or the like, and the necessary amount is supplied from an ink container 13 or the like containing ink by a supply means such as an ink supply hose 14 or the like. It is common to use an automatic ink supply device that automatically supplies ink to the inker section as needed.

An ink container 13 containing ink as an ink supply source is set in the automatic ink supply device. When the ink container is set in the automatic ink supply apparatus, the ink in the ink container is directly inspected by the inspection unit 1 having the means for irradiating infrared light and the means for receiving reflected light in FIG. The container 13 is a transparent container that transmits light, and the inspection unit 1 inspects the ink in the transparent container from the surface of the transparent container. Compared with the reference value set in advance in the control unit 2, if the reference range is exceeded, a signal is sent because the ink container is set incorrectly, the automatic ink supply device is automatically stopped, and the display alarm unit 3 By using an ink supply monitoring device that displays an abnormality or issues an alarm, an ink supply error can be prevented.
Since an ink container setting error can be found before ink supply, it is possible to prevent the occurrence of abnormal products that have eliminated the usefulness of the invisible function due to an ink supply error.

  In this example, since the infrared transmission absorption pair ink was used, the irradiation means and the light receiving means constituting the inspection unit were means adapted to infrared light, but when using ink of other characteristics, What is necessary is just an irradiation means and a light receiving means of a specific light source adapted to the invisible characteristics of the ink to be used, for example, if it is an inspection unit equipped with an ultraviolet light irradiation means and a means for receiving fluorescence emission of ink by ultraviolet light, It is also possible to inspect the characteristics of colorless fluorescent light-emitting ink, which is an invisible characteristic ink.

It is the schematic of the ink supply monitoring apparatus which is one Example of this invention. It is a flowchart of the ink supply monitoring method performed in this invention. It is a figure which shows the example of installation of the ink supply monitoring apparatus of a present Example. It is sectional drawing of the example of a printing part structure of the printing machine which attaches the ink supply monitoring apparatus of a present Example. It is a figure which shows the example of installation of the ink supply monitoring apparatus at the time of dividing | segmenting the inker part of a printing machine into four places, and using four types of ink simultaneously. It is the schematic of the ink supply monitoring apparatus at the time of using a CCD camera. It is the schematic which installed the ink supply monitoring apparatus in the ink container of the ink automatic supply apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inspection part 2 Control part 3 Display alarm part 4 Inker part 5 Ink discharge roller 6 Plate cylinder 7 Impression cylinder 8 Wiping roller 9 Filling roller 10 Inkwell 11 CCD camera sensor 12 Infrared light source 13 Ink container 14 Ink supply hose

Claims (2)

A monitoring device for continuously non-contact inspecting the characteristics of ink having invisible characteristics supplied to a printing press,
The invisible ink is an infrared ink having different spectral characteristics in the infrared region,
The inker part in the printing press for supplying the infrared ink is formed of a material having an infrared reflection characteristic so that the surface of the ink discharge roller detects the spectral characteristic of the infrared region,
An irradiating means for irradiating infrared light to the infrared ink and a light receiving means for receiving reflected light from the infrared ink irradiated with the infrared light, provided above the ink discharge roller. An inspection department ;
A control unit for comparing and determining the measurement reference range stored in advance with the measurement value of the infrared ink inspected by the inspection unit;
An ink supply monitoring device comprising a display alarm unit for notifying an operator of a determination result in the control unit. The control unit is a storage unit that stores a reference range set based on a measurement value obtained by the inspection unit when the infrared ink is normally supplied, a determination result, and relationship information at the time of determination; A determination unit that compares the reference range stored in the storage unit with the measured value of the infrared ink supplied to the printing machine and determines whether or not the reference range is set in advance, and the determination by the determination unit The ink supply monitoring apparatus according to claim 1, further comprising command means for stopping the printing press when the result is defective.

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