JP2011163676A - Sheet drying control device, drying control method and sheet drying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve drying quality of a sheet in a drying device body drying the sheet. <P>SOLUTION: This sheet drying control device 1 controlling drying operation of the drying device body 3 having a drying block drying the sheet 2 by volatilizing a solvent included in the sheet 2 while the sheet 2 is carried includes: a measuring means measuring a volatile gas component concentration of gas volatilized from the sheet 2 by laser beams having wavelength in the infrared region; and a control means adjusting intensity of action for drying the sheet 2 in the drying device body 3 to control the drying operation based on the volatile gas component concentration measured by the measuring means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sheet drying control apparatus that controls a drying operation of a drying apparatus body that dries a sheet, and more particularly to a technique for improving the drying quality of a sheet in the drying apparatus body.

  There are various types of sheets such as paper, film, and metal plate. The sheet is generally called a web in a continuously wound state (for example, wrapping paper) or a sheet that is not continuous. There are things. Then, for example, the sheet is coated (printing process) with a volatile organic solvent mixed with ink, and then dried by the drying apparatus main body. The main body of the sheet drying apparatus is controlled by applying an action of drying the sheet (hereinafter referred to as “drying action”) by, for example, heated hot air, etc., and adjusting the strength of the drying action by the temperature of the hot air. The

  Here, when the drying apparatus main body is operated so that the drying action having the optimum strength acts on the sheet, the drying quality of the sheet (for example, the presence or absence of wrinkles, blurring, and the degree thereof) becomes optimum. However, the optimum strength of the drying action of the sheet is, for example, the type of the sheet substrate, the thickness of the sheet to be dried and the amount of ink applied (hereinafter referred to as “printing conditions”), and the installation environment of the drying apparatus body (for example, It depends on conditions such as ambient temperature and atmospheric pressure. Therefore, when the printing conditions change, the optimum strength of the drying action also changes. Therefore, if the drying apparatus main body is not operated by adjusting the strength of the drying action according to the change of the printing conditions etc., the degree of drying will be excessive or insufficient. There is a case. For example, when the strength of the drying action is excessive, the degree of drying of the sheet increases, discoloration and cracking occurs on the surface of the sheet, and when the strength of the drying action is insufficient, the degree of drying of the sheet decreases, and the organic solvent However, it remains on the sheet (for example, the printing material) and smells, or the sheet is smudged, wrinkled or wavy, and the dry quality of the sheet is generally lowered. Therefore, there is a demand for a sheet drying control technique that can satisfactorily dry a sheet regardless of changes in printing conditions and the like.

  Conventionally, as a drying apparatus for drying a sheet, for example, there is one described in Patent Document 1 or the like. The drying device described in Patent Document 1 divides a heating device that heats and drys a printed material after application of a solvent with hot air into a first zone and a second zone, and measures the surface temperature of the printed material at the exit of each zone. The drying control device controls the hot air temperature in each zone so that the temperature becomes a predetermined value. As a result, regardless of the change in printing conditions, the surface temperature of the printed material at the exit of each zone is dried so as to be a predetermined temperature, thereby suppressing the deterioration of the quality of the printed material.

Japanese Patent No. 2729802

  By the way, the drying of the sheet is an act of volatilizing a solvent or the like from the sheet, for example. Therefore, in the sheet drying process, the volatile state of the solvent volatilized from the sheet is measured, and the result of the drying action (for example, hot air action in heat drying, vacuum action in vacuum drying, etc.), in other words, the degree of drying is quantitative. It is desirable to manage directly to the dry quality.

  However, the control device of the conventional drying apparatus main body described in Patent Document 1 described above pays attention to the surface temperature of the printed matter as a management item of the drying process, and controls the hot air temperature so that the temperature becomes a predetermined value. It is the structure to do. The surface temperature of the printed material is only an indirect parameter indicating the effect of the drying action, and the above-described conventional control apparatus quantitatively determines the result of the drying action (the degree of drying) that actually appears by applying the drying action at a predetermined strength. Not manage directly. Therefore, there exists a problem that the management precision about the drying quality in the drying process of a sheet | seat is inferior.

  The present invention was made paying attention to the above problems, and by directly managing the result of the drying action of the sheet drying apparatus main body, the management accuracy of the drying quality in the sheet drying process is improved, and the sheet An object of the present invention is to provide a sheet drying control apparatus, a drying control method, and a sheet drying apparatus that improve the drying quality of the sheet.

  In order to achieve the above object, a sheet drying control apparatus according to the present invention controls a drying operation of a drying apparatus main body having a drying block that volatilizes a solvent contained in the sheet and dries the sheet while conveying the sheet. In the drying control apparatus, based on the volatile gas component concentration of the gas that volatilizes from the sheet, the measuring device that measures the concentration of the volatile gas with laser light having an infrared wavelength, and the volatile gas component concentration that is measured by the measuring device, the drying device body And a control means for controlling the drying operation by adjusting the strength of the action of drying the sheet.

  With such a configuration, the volatile gas component concentration of the gas volatile from the sheet is measured by the measuring means with laser light having an infrared wavelength, and the control means is used to dry the volatile gas component concentration based on the volatile gas component concentration measured by the measuring means. The drying operation is controlled by adjusting the strength of the action of drying the sheet in the apparatus main body. As a result, the volatile gas component concentration of the gas that volatilizes from the sheet is measured to grasp the volatilization state of the gas, thereby directly and quantitatively managing the result (drying degree) of the action of drying the sheet by the drying apparatus body.

  According to a second aspect of the present invention, the measuring means transmits the laser light having a wavelength in the infrared region to the volatile region of the gas volatile from the sheet in the drying block and the gas volatile region. It is preferable to have a configuration that includes a light receiving unit that receives the laser beam to be measured, and that measures the volatile gas component concentration of the gas that volatilizes from the sheet in the gas volatilization region based on the light reception intensity of the light receiving unit.

  Further, as in claim 3, the control means dries the sheet in the main body of the drying apparatus so that the volatile gas component concentration measured by the measuring means approaches a preset target value of the volatile gas component concentration. The drying operation may be controlled by adjusting the strength of the action to be performed.

  Furthermore, as in claim 4, a plurality of the drying blocks are provided along the sheet conveying direction in the drying apparatus main body, the measuring means is arranged for each drying block, and the control means The target value of the volatile gas component concentration is preset for each drying block, the strength of the action of drying the sheet in the drying apparatus main body is adjusted, and the drying operation is controlled for each drying block. Good. Thus, the measuring means measures the volatile gas component concentration of the gas that volatilizes from the sheet in the gas volatilization region based on the light receiving intensity of the light receiving portion, and the control means provides a plurality of volatile gas component concentrations along the sheet conveying direction in the drying apparatus main body. Based on the volatile gas component concentration measured by each measuring means arranged for each drying block, the drying operation is controlled by adjusting the strength of the action of drying the sheet in the drying apparatus body for each drying block.

  According to a fifth aspect of the present invention, the measurement unit may be configured to be capable of measuring the volatile gas component concentration on the terminal end side in the sheet conveyance direction in the drying block.

  Further, according to a sixth aspect of the present invention, the measuring unit may be configured to be capable of optical scanning the laser beam within the drying block.

  Furthermore, as described in claim 7, the gas to be measured by the measuring means is preferably composed mainly of a volatile organic compound.

  Further, as in claim 8, the gas to be measured by the measuring means may contain water as a main component.

  Further, according to a ninth aspect of the present invention, the light projecting unit and the light receiving unit may be arranged to face each other with the volatile region interposed therebetween.

  Still further, according to a tenth aspect of the present invention, the measuring unit includes a reflecting mirror that reflects the laser light that passes through the volatile region, and the light projecting unit and the light receiving unit are opposed to the reflecting mirror and the volatile device. You may make it the structure arrange | positioned on both sides of an area | region.

  Further, according to a eleventh aspect of the present invention, the reflecting mirror may be configured such that the light receiving intensity of the laser light in the light receiving unit can be adjusted by adjusting the optical axis of the reflected laser light.

  Furthermore, as in claim 12, the reflecting mirror may be a retroreflector.

  In addition, as in the thirteenth aspect, the wavelength of the laser light projected from the light projecting unit may be a mid-infrared wavelength.

  Furthermore, in order to achieve the above-mentioned object, the drying control method according to the present invention includes a drying block for drying a sheet by volatilizing a solvent contained in the sheet while conveying the sheet. A drying control method for controlling a drying operation of an apparatus main body, wherein the concentration of volatile gas components of a gas volatile from a sheet in the drying block is measured with a laser beam having an infrared wavelength, and the volatile gas component concentration is measured. And controlling the drying operation by adjusting the strength of the action of drying the sheet in the main body of the drying device.

  Further, as in claim 15, laser light having a wavelength in the infrared region is projected from a sheet in the drying block to a volatile region of gas that is volatilized, and laser light that passes through the volatile region of gas is received and received. It is preferable that the volatile gas component concentration of the gas volatile from the sheet in the gas volatile region is measured based on the received light intensity of the laser beam.

  Furthermore, as described in claim 16, the drying operation is performed by adjusting the strength of the action of drying the sheet in the drying apparatus main body so that the measured volatile gas component concentration approaches the target value of the preset volatile gas component concentration. You may make it the structure controlled.

  Furthermore, as in claim 17, a plurality of drying blocks are provided along the sheet conveying direction in the drying apparatus main body, the volatile gas component concentration of the gas is measured for each drying block, and the target value of the volatile gas component concentration is determined. It is preferable that the drying operation is controlled for each drying block by setting in advance for each drying block and adjusting the strength of the action of drying the sheet in the drying apparatus main body.

  Further, as described in claim 18, the volatile gas component concentration may be measured by measuring the volatile gas component concentration on the terminal side in the sheet conveying direction in the drying block.

  Further, the measurement of the concentration of the volatile gas component may be performed by optically scanning the laser beam within the drying block.

  In order to achieve the above object, a sheet drying apparatus according to the present invention causes a sheet drying control apparatus according to any one of claims 1 to 13 and a sheet to be conveyed, as in claim 20. A drying apparatus main body having a drying block that volatilizes the solvent contained in the sheet and dries the sheet, and controls the drying operation of the drying apparatus main body by the sheet drying control device to dry the sheet. Features.

  According to the sheet drying control apparatus or the drying control method of the present invention, the volatile gas component concentration of the gas that volatilizes from the sheet is measured by laser light having an infrared wavelength, and based on the volatile gas component concentration measured by the measuring means, The drying operation can be controlled by adjusting the strength of the action of drying the sheet in the main body of the drying apparatus. As a result of the action of drying the sheet by the main body of the drying apparatus by measuring the volatile gas component concentration of the gas volatile from the sheet and grasping the volatilization state of the gas, in other words, the degree of drying can be directly managed quantitatively. It is possible to improve the accuracy of quality control in the sheet drying process. In this way, it is possible to provide a sheet drying control device and a drying control method that improve the drying quality of the sheet. In addition, according to the sheet drying apparatus including the sheet drying control apparatus configured as described above, the result of the drying operation is directly managed quantitatively, and the management accuracy of the drying quality in the sheet drying process is enhanced, The dry quality of the sheet can be improved and the sheet can be dried.

1 is a schematic configuration diagram illustrating a first embodiment of a sheet drying control apparatus according to the present invention. It is a schematic top view about the sheet drying control apparatus of the said 1st Embodiment. It is a schematic partial top view which shows the structural example which suppresses adhesion of the volatile organic solvent to a light projection part and a light-receiving part. It is explanatory drawing showing an example of the relationship between the molar absorption coefficient and a wavelength, and the difference of the transmittance | permeability according to column concentration. It is a flowchart which shows the control operation of the sheet drying control apparatus of the said 1st Embodiment. It is a schematic top view which shows 2nd Embodiment of the sheet drying control apparatus which concerns on this invention. It is a schematic top view which shows 3rd Embodiment of the sheet drying control apparatus which concerns on this invention. It is a schematic block diagram which shows the specific structural example of the measurement means in the said 3rd Embodiment. It is explanatory drawing explaining the optical scanning direction of the laser beam in the said 3rd Embodiment. It is a schematic top view which shows 4th Embodiment of the sheet drying control apparatus which concerns on this invention. It is explanatory drawing explaining the fall state of the conveyance distance of a sheet | seat, and the density | concentration of the solvent which remains on a sheet | seat. It is a flowchart which shows the control operation of the sheet drying control apparatus of the said 4th Embodiment.

Hereinafter, an embodiment of a sheet drying control device according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating a first embodiment of the sheet drying control apparatus, and FIG. 2 is a schematic top view of the sheet drying control apparatus of the present embodiment.
1 and 2, a sheet drying control apparatus 1 according to this embodiment controls a drying operation of a drying apparatus body 3 that dries a sheet 2, and includes a light projection control unit 4, a light receiving unit 5, and a drying control unit. 6.

  The sheet 2 is made of, for example, paper or film as a base material, and is generally referred to as a web in a continuously wound state (for example, a wound paper) or a non-continuous sheet. It is foliate. For example, the sheet 2 is coated (printing process) with a volatile organic solvent mixed with ink, and then, as shown in FIG. 2, the sheet 2 is transported into the drying apparatus main body 3 to be dried and transported to the next process. The Further, as shown in FIG. 2, for example, the sheet 2 is formed with a width W1 in a direction orthogonal to the sheet conveying direction.

  The drying device body 3 is for drying the sheet 2 by volatilizing the solvent contained in the sheet 2 while transporting the sheet 2, and as shown in FIG. 1, for example, a transport unit 7 for transporting the sheet 2 The heat generating unit 8 serving as a heat source for drying the sheet 2, the air blowing unit 9 that blows air heated by the heat generating unit 8 to the sheet 2, and the housing 10, for example, It is a general one to show.

  As shown in FIG. 2, the drying apparatus main body 3 is also for carrying out the sheet 2 carried in from a previous process (left side of the drawing) such as a printing process to the subsequent process (right side of the drawing). Although not shown, a slit having an appropriate size is provided for allowing the sheet 2 to be carried in and out. Further, as shown in FIG. 3, for example, an opening is provided on the side surface of the housing 10 so that laser light projected from a light projecting unit 13 of the light projecting control unit 4 to be described later can pass therethrough. The light receiving unit 5 and the light projecting unit 13 described later are attached from the outside of the housing 10 together with a cover for closing the unit. Furthermore, although not shown, the housing 10 includes means for exhausting gas that volatilizes from the sheet 2. This exhaust means is for preventing gas from staying, and is formed, for example, at a location that does not interfere with laser light reception and light projection by the light receiving unit 5 and the light projecting unit 13 so as not to hinder gas measurement. ing. The housing 10 forms a drying block that is an area for drying the sheet 2. Then, the sheet 2 is given, for example, hot air in this drying block, and is gradually dried during conveyance, and is measured on the terminal end side (right side in FIG. 2) in the sheet conveyance direction in the drying block. Drying is performed so that the gas component concentration is, for example, an allowable value (hereinafter referred to as “volatile gas component allowable concentration”). The permissible concentration of the volatile gas component varies depending on, for example, the type of the sheet 2.

  And the drying apparatus main body 3 is comprised so that adjustment of the sheet | seat conveyance speed of the conveyance part 7, the temperature of the heat generating part 8, the ventilation volume of the ventilation part 9, etc. can be adjusted, for example, and the intensity | strength (for example, drying action) which dries the sheet | seat 2 The temperature of the heat generating part, the air flow rate, the conveyance speed, and the drying time) can be adjusted. Here, the strength of the drying action depends on the printing conditions (for example, the type of sheet base material, the thickness of the sheet to be dried, the amount of ink applied, etc.), the purpose of drying (for example, for the purpose of energy-saving operation), and the drying The optimum value generally differs depending on the installation environment (for example, ambient temperature, atmospheric pressure, etc.) of the apparatus body 3.

  The light projection control unit 4 is a control unit for measuring the volatile gas component concentration of the gas volatilized from the sheet 2 by using an infrared absorption phenomenon by the gas. As shown in FIG. A light projecting unit 13 that projects a laser beam having an infrared wavelength to a volatilizing region 12 of a gas that is volatilized from the sheet 2 in the drying block in response to a command from the measuring device control unit 11; , And is configured.

  As shown in FIG. 1, the measurement instrument control unit 11 sets the wavelength and output of laser light projected from a light projecting unit 13 described later, and instructs the laser light oscillation unit 16 described later. As will be described later, the laser light oscillation unit 16 is constituted by, for example, a laser diode. The wavelength and output of the laser light can be set, for example, by adjusting the temperature of the laser diode, adjusting the current input to the laser diode, or modulating the current. Further, based on the light reception intensity of the light receiving unit 5 to be described later, the concentration of the volatile gas component of the gas volatile from the sheet 2 in the volatile region 12 is measured. Therefore, the measurement device control unit 11 also has a function of calculating the volatile gas component concentration. Note that the laser light projection region 15 (measurement area volume represented by the product of the laser beam cross-sectional area and the optical path length of the laser light) whose approximate range is indicated by a two-dot chain line in FIG. 2 is the actual measurement in the volatile region 12. It is an area. And the volatile-gas component density | concentration calculated by the measurement equipment control part 11 can be used as the parameter | index which represents the result (drying degree) of the drying effect | action by the drying apparatus main body 3 quantitatively. The concentration of the volatile gas component does not indicate the concentration of the solvent remaining in the sheet 2 (hereinafter referred to as “solvent residual concentration”), but is the concentration of the gas volatilized from the sheet 2 at the time of measurement.

  The light projecting unit 13 receives a command from the measuring device control unit 11 and projects laser light having a wavelength in the infrared region to the volatilizing region 12 of the gas that volatilizes from the sheet 2 in the drying apparatus body 3. As shown in FIG. 2, the laser light oscillation unit 16 and the light projecting optical system 17 are provided.

  As shown in FIG. 3A, the light projecting unit 13 and the light receiving unit 5 described later are attached to the outside of the housing 10 together with a closing cover that closes an opening provided in the housing 10, for example. Then, for example, a fan is provided so that a pressurized airflow flows from the opening toward the inside of the housing 10 to suppress the volatilized solvent from adhering to the light projecting unit 13 and the light receiving unit 5 described later. . Thereby, it is possible to perform remote and non-contact measurement without contacting the light projecting unit 13 and the light receiving unit 5 described later with the measurement target gas, and the solvent adhesion to the light projecting unit 13 and the light receiving unit 5 described later. Suppress. As another method, as shown in FIG. 3B, a glass material (for example, calcium fluoride) having a high transmittance of a laser wavelength used for measurement is provided as the window material 31 so that the light receiving unit 5 In addition, the light projecting unit 13 can be separated from the measurement target gas inside the housing 10 and solvent adhesion can be suppressed. In the present embodiment, as shown in FIG. 2, the light projecting unit 13 and the light receiving unit 5 described later are arranged so as to be able to measure the concentration of volatile gas components on the terminal end side (right side in the drawing) in the sheet conveyance direction in the drying block. Has been.

  The laser oscillator 16 receives a command from the measurement instrument controller 11 and generates laser light having a predetermined wavelength and output. In this embodiment, laser light having a wavelength in the mid-infrared region can be generated. It is a simple configuration. Thereby, as will be described later, for example, the volatile gas component concentration of the volatile organic solvent used for oil-based printing can be efficiently measured.

  The light projecting optical system 17 projects laser light toward the volatile region 12, and is composed of, for example, a lens. In addition, since measurement accuracy is so favorable that the laser beam is projected to the surface vicinity of the sheet | seat 2, it is good to project a laser beam within 10 mm from the surface of the sheet | seat 2, for example.

  As shown in FIG. 1, the command transmission unit 14 outputs a control signal from the measurement device control unit 11 to the drying control unit 6 described later.

  The light receiving unit 5 receives laser light that passes through the gas volatilization region 12, and includes a light receiving optical system 18 and a light receiving element 19, as shown in FIG.

  The light receiving optical system 18 inputs laser light transmitted through the gas volatilization region 12 to the light receiving element 19, and is constituted by, for example, a lens.

  The light receiving element 19 is, for example, an element having good sensitivity to laser light having a wavelength in the infrared region. The light receiving element 19 receives laser light transmitted through the volatile region 12 via the light receiving optical system 18 and corresponds to the received light intensity. An output is generated and input to the measurement device controller 11.

  Here, in the present embodiment, as shown in FIGS. 1 and 2, the light projecting unit 13 and the light receiving unit 5 are arranged to face each other with the volatile region 12 interposed therebetween. The optical axis of the light projecting unit 13 and the light receiving unit 5 can be adjusted to a position where the maximum value is obtained, and the signal of high S / N (representing the ratio of the signal and the noise component and indicating the relative smallness of the noise component) Can be obtained. Further, the noise component (N) of the signal (S) increases as the optical path length of the laser light is longer, for example. In the present embodiment, since the optical path length of the laser beam corresponds to, for example, the width W2 (see FIG. 2) of the drying apparatus main body 3, the optical path length of the laser beam is, for example, dry as in the second embodiment described later. Compared to the case where the width W2 of the apparatus body 3 is doubled, the noise component can be reduced.

  The drying control unit 6 controls a drying operation in the drying apparatus main body 3 based on a command from the command transmission unit 14, and as shown in FIG. 1, a command reception unit 20, a drying device control unit 21, and the like. , And is configured.

  As shown in FIG. 1, the command receiving unit 20 receives a control signal from the command transmitting unit 14 and outputs the control signal to the drying device control unit 21.

  As shown in FIG. 1, the drying device control unit 21 controls the drying operation of the drying apparatus main body 3 with the strength of the drying action based on the control signal from the command receiving unit 20.

  In the present embodiment, the measurement device control unit 11 sets, for example, the volatile gas component allowable concentration described above as a target value of the volatile gas component concentration measured on the terminal end side in advance, and outputs the light reception output from the light receiving element 19. The volatile gas component concentration measured based on the target value of the volatile gas component concentration set in advance is adjusted, and the drying action intensity in the drying device main body 3 is adjusted so that the measured value approaches the target value. The drying operation of the main body 3 is configured to be controlled via the drying control unit 6. Note that, when adjusting the strength of the drying action, for example, the strength of the drying action of at least one of the transport unit 7, the heat generating unit 8, and the air blowing unit 9 is adjusted. Further, for example, even if the drying apparatus body 3 is commanded so as to act on the sheet 2 with a drying action with a predetermined strength according to the printing conditions, the state of the drying apparatus body 3 itself at that time, and the above-described printing conditions In addition, due to an unexpected change in the installation environment of the drying apparatus main body 3 or the like, there may be a case where the intended result of the drying action (degree of drying) cannot be obtained. When the unexpected change as described above occurs, the measurement device control unit 11 in the present embodiment can monitor the change by comparing the measurement result of the volatile gas component concentration with the target value, for example. it can. For example, when the measured value is higher than the target value (allowable value), it is determined that the solvent remains in the sheet 2 more than expected on the end portion side. When the measured value is lower than the target value, the end portion On the side, it is determined that the sheet 2 is dried more than expected, and a control signal is output so that the measured value approaches the target value.

  Further, in the present embodiment, the target value of the volatile gas component concentration can be set in advance in the measuring device control unit 11, and for example, each of the drying action intensity and the volatile gas component concentration corresponding to various printing conditions and the like. The target value data can be saved in a rewritable manner. When controlling the drying operation of the drying apparatus main body 3 under the same printing conditions, for example, the printing conditions are selected and the target values of the strength of the drying action and the volatile gas component concentration corresponding to the conditions are read out. Can be selected.

  In the present embodiment, the measurement unit is configured to include the measurement device control unit 11, the light projecting unit 13, and the light receiving unit 5, and the control unit includes the measurement device control unit 11, the command transmission unit 14, and the like. The drying control unit 6 is provided. As described above, the measurement device control unit 11 is a component of the measurement unit and a component of the control unit.

  Here, the measuring means configured to include the measuring device control unit 11, the light projecting unit 13, and the light receiving unit 5 measures the volatile gas component concentration using an infrared absorption phenomenon caused by gas. The measurement principle of the volatile gas component concentration in this embodiment will be described below.

The energy of the laser beam transmitted through the gas volatile region 12 is attenuated by energy absorption by the gas medium in the volatile region 12. The light transmittance T (λ) by the gas medium is defined by the following equation (1).
T (λ) = I1 (λ) / I0 (λ) (1)
Here, λ is the wavelength of light, I1 (λ) is the intensity of light transmitted through the gas medium, and I0 (λ) is the intensity of light incident on the gas medium. The light transmittance T (λ) can be expressed by the following equation (2) according to the Lambert-Beer law representing the relationship between concentration and light attenuation.
lnT (λ) = − ε (λ) CL (2)
Here, ε (λ) is a molar absorption coefficient of the gas medium, and is a coefficient for each wavelength indicating how much light the gas medium absorbs when the light is incident on the gas medium. C is the molar concentration of the gas medium, and L is the thickness of the gas medium through which light passes. In addition, the concentration of the gas medium may be evaluated by the column concentration CL (product of the molar concentration C and the thickness L of the gas medium).

  The transmittance T (λ) can be obtained from the ratio between the received light intensity detected by the light receiving unit 5 and the projection intensity of the laser light projected from the light projecting unit 13. Therefore, if the molar extinction coefficient ε (λ) and the thickness L of the gas medium through which light passes are known, the molar concentration C or the column concentration CL of the gas medium in the laser light projection region 14 according to the above equation (2). And the molar concentration C or the column concentration CL can be measured as the volatile gas component concentration.

  FIG. 4 is an explanatory diagram showing the relationship between the molar extinction coefficient ε (λ) of ethyl acetate often used as an ink solvent and the wavelength, and the difference in transmittance depending on the column concentration CL. For example, when a laser having a gas medium thickness of 1 m and a wavelength of 3.35 μm is projected, the transmittance T (λ) is about 95% when the volatile gas component concentration of ethyl acetate is 100 ppm · m. In the case of 1,000 ppm · m, it shows about 70%, and in the case of 10,000 ppm · m, it shows about 3%. It can be seen that the transmittance T (λ) changes depending on the concentration. Further, as shown in FIG. 4, the molar extinction coefficient ε (λ) changes according to the wavelength λ, and ethyl acetate has a peak around 3.34 to 3.35 (hereinafter referred to as “light absorption wavelength band”). ) The transmittance T (λ) changes greatly in the vicinity of this light absorption wavelength band. Therefore, when laser light having a wavelength λ near the light absorption wavelength band is projected from the light projecting unit 13, the measurement sensitivity is improved.

  Here, as another method for measuring the concentration of volatile gas components, for example, in a measurement method using FT-IR (Fourier transform infrared spectroscopy), filter spectroscopy, or the like, a few seconds to several minutes for one measurement. Take it. However, in the configuration of the present embodiment, laser light with a predetermined wavelength can be projected onto the volatile region 12 and measurement can be performed at high speed based on the principle described above. Further, as will be described later, even in a configuration including a planar type optical scanning means using, for example, semiconductor manufacturing technology for scanning laser light in the volatile gas region 12, scanning can be performed in sub-millisecond units. Furthermore, even if the measurement result obtained by scanning is averaged by the measurement device control unit 11, a control signal can be output to the drying control unit 6 at intervals of several milliseconds. Therefore, the drying operation of the drying apparatus main body 3 can be controlled in real time, and high-precision measurement is possible even with the drying apparatus main body 3 having a high sheet conveyance speed.

  Next, the control operation of the sheet drying control apparatus 1 according to the present embodiment will be described with reference to FIGS. In the following description, for example, the volatile gas component allowable concentration determined according to the type of the sheet 2 is set as a target value, and the strength of the drying action such that the target value is measured on the terminal end side (for example, the temperature of the heating unit, It is assumed that the amount of blown air, the conveyance speed, and the like are obtained in advance for each type of the sheet 2 through experiments, past data, and the like. And the data (hereinafter referred to as the width W1 of the sheet, the intensity of each drying action corresponding to various sheets 2 and the permissible concentration of each volatile gas component and its permissible range, the wavelength and output of the laser light, the molar extinction coefficient for each wavelength, etc. In the following description, it is assumed that “initial data” is rewritable, for example, already stored in the memory in the measurement device controller 10 and the creation of the initial data (step S1) has been completed.

  First, initial data corresponding to the type of the sheet 2 selected by an operator or the like who operates the sheet drying control apparatus 1 is read from the memory in the measurement device control unit 11. Thereby, a target value is set. Then, based on the initial data, the measurement device control unit 11 instructs the drying device control unit 21 via the command transmission unit 14 and the command reception unit 20 on the strength of the drying action, and from the drying device control unit 21, for example, A control signal is output to the transport unit 7, the heat generation unit 8, and the air blowing unit 9 to start the drying operation of the drying apparatus body 3 with a predetermined drying action intensity, and the wavelength of the laser light projected from the light projecting unit 13 The output is set and commanded to the laser beam oscillation unit 16 (step S2). Next, the laser light oscillation unit 16 receives a command from the measurement device control unit 11 and generates laser light having a wavelength in the mid-infrared region, for example, with a predetermined output. The light projecting optical system 17 projects laser light toward the volatile region 12. The laser beam attenuated through the volatile region 12 enters the light receiving element 19 through the light receiving optical system 18. The light receiving element 19 receives the laser light, generates an output corresponding to the received light intensity, and inputs the output to the measuring instrument control unit 11. The measuring device control unit 11 calculates the transmittance T (λ) based on the ratio between the received light intensity and the light projecting intensity of the laser light projected from the light projecting unit 13. Then, the molar extinction coefficient ε (λ) is determined according to the set wavelength of the laser light, the thickness L of the gas medium through which the light is transmitted is determined as the sheet width W1, for example, the molar concentration C is calculated, and this molar concentration C Is the measurement result of the volatile gas component concentration (step S3). Furthermore, the measuring device control unit 11 determines whether the measured volatile gas component concentration is within the allowable range of the target value. If the measured value is within the allowable range, the measurement device control unit 11 determines that the planned dry state is present, and outputs a command to drive the drying device body 3 with the same drying action intensity to the drying control unit 6. Then, the process returns to step S3 and is measured again (step S4). When the measured volatile gas component concentration is outside the allowable range, the process proceeds to the next step S5. Finally, as step S5, when the measured volatile gas component concentration is lower than the lower limit value of the allowable range, the measuring device control unit 11 determines that the sheet 2 is dried more than expected on the terminal end side. For example, a control signal for reducing a predetermined amount of the drying action intensity set in advance by at least any one of the transport unit 7, the heat generating unit 8, and the air blowing unit 9 so that the volatile gas component concentration approaches the target value is supplied to the drying control unit. 6 is output. When the measured volatile gas component concentration is higher than the upper limit value of the allowable range, the measuring device control unit 11 determines that the solvent remains in the sheet 2 more than expected on the terminal end side, and the volatile gas component For example, a control signal is output to the drying control unit 6 so as to increase a predetermined amount by which the intensity of the drying action of at least one of the conveyance unit 7, the heat generation unit 8, and the air blowing unit 9 is set in advance so that the concentration approaches the target value . (Step S5). And the drying operation | movement to the said steps 3-5 is performed until it reaches a predetermined volatile gas component density | concentration. In this way, a control signal based on the determination result of the measurement device control unit 11 is output to the drying control unit 6 to control the drying operation of the drying apparatus body 3.

  In the above description of the control operation, calculations such as storage and selection of initial data, comparison between measurement results and target values, and determination of the dry state have been described by the measurement device control unit 11. However, the present invention is not limited to this. Alternatively, the drying device control unit 21 may perform the configuration. In this case, the drying device control unit 21 receives the measurement result of the volatile gas component concentration from the light projection control unit 4, performs the above-described calculations based on the measurement result, and outputs a drive command to the drying apparatus main body 3. In this case, the measuring means is composed of the light projection control section 4 and the light receiving section 5, and the control means is composed of the drying control section 6.

  With such a configuration, the sheet drying control device 1 according to the present embodiment measures the concentration of volatile gas components of the gas from the sheet 2, grasps and determines the volatilization state of the gas, and thereby performs the drying action of the drying device body 3. As a result, the degree of drying can be directly managed quantitatively, the accuracy of quality control in the drying process of the sheet 2 can be improved, and the drying operation of the drying apparatus body 3 can be controlled. In this way, the sheet drying control apparatus 1 that improves the sheet drying quality can be provided. Further, the drying operation of the drying apparatus main body 3 can be easily controlled according to the selected condition (for example, the type of the sheet 2 or the like). Then, for example, the measured volatile gas component concentration approaches the target value so that a constant drying result can be obtained even if an unexpected change occurs in the installation environment of the drying apparatus body 3 or printing conditions. Since the degree of drying of the sheet can be managed by controlling the strength of the drying action, the drying quality is stabilized and the drying quality is improved. Further, for example, when it is determined that the sheet 2 is dried more than expected, it is possible to control to reduce the strength of the drying action, so that no extra power is consumed and the drying device main body 3 is not consumed. It is also possible to save power.

  In addition, in this embodiment, although the light-receiving part 5 and the light projection part 13 demonstrated in the case where it arrange | positions so that measurement of the volatile-gas component density | concentration of the terminal part side (right side of drawing) of a drying block is possible, as shown in FIG. Not only the case where it arrange | positions in the terminal part side, but the structure arrange | positioned so that measurement of the volatile-gas component density | concentration of the starting end part (left side of drawing) of the sheet conveyance direction in a drying block may be sufficient. In this case, the measurement device control unit 11 sets the target value of the volatile gas component concentration to be measured to a value higher than the target value in the case where the measurement is performed at the terminal portion, for example. When the measured value is lower than the target value, it is determined that it is difficult to dry, and the drying action is determined. It is preferable that a control signal for increasing the intensity of the ink is output to the drying control unit 6 by a predetermined amount.

  Here, as another method for measuring the volatile gas component concentration, for example, a chemical reaction type detection tube, a dielectric type or semiconductor type electronic sensor, FT-IR, filter spectroscopy, or NDIR (non-dispersive infrared spectroscopy) A measurement method using an infrared sensor or the like is known. However, both are generally batch measurements, which require manpower for sampling and measurement. On the other hand, the sheet drying control apparatus 1 according to the present embodiment can automatically measure during a drying operation without collecting a sample for measurement or stopping the drying apparatus main body 3 for sampling. Labor can be promoted. Moreover, since the sheet drying control apparatus 1 according to the present embodiment is configured to suppress adhesion of the volatile solvent to the light projecting unit 13 and the light receiving unit 5 as described above, the light projecting unit 13 using the volatile solvent and Contamination of the light receiving unit 5 is suppressed, and maintenance work and costs can be reduced. Furthermore, in FT-IR, a light source in which energy is distributed over a wide wavelength range is used, but since the output for each wavelength is low, the S / N of the obtained signal is generally low. On the other hand, the sheet drying control apparatus 1 according to the present embodiment projects laser light of a predetermined wavelength onto the volatile region 12 and measures the volatile gas component concentration. Therefore, since the output is concentrated in a narrow wavelength range, a signal having an S / N higher than that of FT-IR can be obtained.

By the way, for example, when ink used in the printing process is classified, there are oil-based ink and water-based ink. By using each of them, printing is classified into oil-based printing and water-based printing. The oil-based ink is prepared by mixing, for example, an ink pigment in a volatile organic solvent such as toluene, ethyl acetate, isopropyl alcohol, methyl ethyl ketone, and methanol. A water-based ink is prepared using water or alcohol as a solvent. Here, the wavelength of the laser light generated from the laser light oscillation unit 15 is preferably in the light absorption wavelength band as described above. For example, it is known that an organic light absorption wavelength mainly exists in the 2.5 to 16 μm region, and an inorganic light absorption wavelength mainly exists in the 1200 to 2400 nm region. Further, when measuring the concentration of a volatile gas component in a solvent mainly composed of a volatile organic compound (VOC) in oil-based ink, a wavelength in the mid-infrared region having a light absorption wavelength due to —CH bond or —OH bond ( It is preferable to use a laser beam of 3 to 5 μm. For example, the light absorption wavelength band of ethyl acetate, methyl ethyl ketone and the like often used as a solvent for oil-based inks exists in the 3.3 to 3.5 μm region, and it is particularly preferable to use laser light in this wavelength region. Also, when measuring volatile gas component concentration of water vapor _(H 2 O), in the aqueous ink, it is preferable to use laser light 1350~1450nm region and 1850~1950nm region.

  As described above, the laser light oscillation unit 16 in the present embodiment has a configuration capable of generating laser light having a wavelength in the mid-infrared region. Thereby, it is possible to efficiently measure the concentration of volatile gas components of a gas whose measurement target is a volatile organic compound as a main component, for example, a gas that volatilizes from oil-based ink. In addition, the laser light oscillation part 16 in this embodiment generate | occur | produces the laser beam of the wavelength of 2.5-16 micrometers not only in the wavelength (3-5 micrometers) of a mid infrared region, but another kind of volatile organic. The structure which makes measurement object the gas which has a compound as a main component may be sufficient. Further, the laser light oscillation unit 16 in the present embodiment generates, for example, laser light having a wavelength in the range of 1350 to 1450 nm or 1850 to 1950 nm to measure a gas mainly composed of a volatile inorganic material for aqueous printing. It may be configured as follows.

  FIG. 6 is a schematic top view showing the second embodiment of the sheet drying control apparatus 1 according to the present invention. The same elements as those of the first embodiment in FIG. 2 are denoted by the same reference numerals, description thereof is omitted, and only different portions will be described.

  In the present embodiment, as shown in FIG. 6, the light projecting control unit 4 that includes the light projecting unit 13 and the light receiving unit 5 is disposed so as to face the reflecting mirror 22 and sandwich the volatile region 12. is there. Here, the measurement means in the present embodiment is configured to include the measurement device control unit 11, the light projecting unit 13, the light receiving unit 5, and the reflecting mirror 22 that reflects the laser light that passes through the volatile region 12. Yes.

  The reflecting mirror 22 is a flat mirror, for example, and reflects the laser light projected from the light projecting unit 13 to the light receiving unit 5. With this configuration, the light projecting unit 13 and the light receiving unit 5 are separate in the configuration of the first embodiment described above. However, in the configuration of the present embodiment, the light projecting unit 13 and the light receiving unit 5 are combined. It can be a body shape.

  In addition, the reflecting mirror 22 in the present embodiment is configured to be capable of adjusting the optical axis of the reflected laser light and adjusting the light receiving intensity of the laser light in the light receiving unit 5 (hereinafter referred to as “optical adjustment”). Good. Thereby, a high S / N signal can be obtained even in an integrated type. Further, the reflecting mirror 22 may be configured as a retroreflector 23 such as a corner cube or a retroreflective sheet. In this case, since the laser beam can be reflected to the light receiving unit 5 without performing optical adjustment work, compared to the case where the light projecting unit 13 and the light receiving unit 5 in the first embodiment requiring optical adjustment work are separate types. Initial setup can be facilitated.

  In general, a longer optical path length of laser light is advantageous when detecting a low-concentration gas. The optical path length of the sheet drying control apparatus 1 according to the present embodiment can be, for example, twice the width W2 (see FIG. 6) of the drying apparatus body 3, and can be longer than that of the first embodiment. . Therefore, a lower concentration gas can be detected as compared with the first embodiment, and the detection lower limit value can be lowered.

  FIG. 7 is a schematic top view showing the third embodiment of the sheet drying control apparatus 1 according to the present invention. FIG. 8 is a schematic configuration diagram showing a specific configuration example of the light projection control unit 4 in the present embodiment, and FIG. 9 is an explanatory diagram for explaining the scanning direction of the laser light in the third embodiment. is there. In addition, the same code | symbol is attached | subjected to the element same as 2nd Embodiment of FIG. 6, description is abbreviate | omitted, and only a different part is demonstrated.

  In the present embodiment, as shown in FIG. 7, the light projection control unit 4 has a configuration capable of optically scanning the laser light projected from the light projection unit 13 within the gas volatilization region 12. In this case, as shown in FIG. 7, the reflecting mirror 22 of the second embodiment may be configured with a retroreflector 23 such as a retroreflective sheet having a large area. Accordingly, even in the present embodiment in which optical scanning is performed, the above-described optical adjustment work is not performed, so that initial setup can be facilitated as compared with the first embodiment. In addition to the configuration provided with the reflecting mirror 22, in the configuration in which the light projecting unit 13 and the light receiving unit 5 are arranged to face each other as in the first embodiment, a plurality of light receiving elements 19 are arranged in a line in the sheet conveying direction, for example. The structure to provide may be sufficient.

  In the configuration example of the light projection control unit 4 shown in FIG. 8, the light receiving optical system 18 transmits, for example, laser light from the laser light oscillation unit 16 and reflects reflected light from the retroreflector 23 (for example, a retroreflective sheet). The beam splitter reflects the light receiving element 19.

  Further, in the configuration example of the light projecting control unit 4 shown in FIG. 8, the light projecting optical system 17 optically scans the laser light transmitted through the light receiving optical system 18, and is, for example, a planar type using semiconductor manufacturing technology. Two-dimensional light scanning means. As a result, the light projection control unit 4 can optically scan the laser light in the horizontal and vertical directions with respect to the sheet conveyance direction, as shown in FIG. The laser beam may be scanned in the horizontal direction in the vicinity of the sheet surface (for example, the height from the surface is about 10 mm or less), and thereby the gas immediately after volatilization can be measured. Further, the present invention is not limited to this, and the optical scanning may be performed by moving the horizontal and vertical directions simultaneously on the surface of the retroreflector 23 in FIG. The optical scanning unit is not limited to the two-dimensional optical scanning unit, but may be, for example, a one-dimensional optical scanning unit capable of optical scanning in the horizontal direction, as long as optical scanning is possible within the gas volatilization region 12. In this manner, the laser light projection area 15 (see FIG. 7), which is an actual measurement area in the volatile area 12, can be widened. Further, as the light projecting optical system 17, an electromagnetically driven galvanometer mirror described in Japanese Patent No. 2722314 can be applied.

  Moreover, the light projection control unit 4 can project the laser light a plurality of times during scanning, and can measure the volatile gas component concentration a plurality of times, for example, within a few milliseconds. Thereby, it is possible to perform a highly reliable measurement with few measurement error problems. In addition, the measurement instrument control unit 11 can average the multiple measurement results obtained to obtain the volatile gas component concentration in the light projection region 15 as the measurement result, and obtain a measurement result that represents the wide measurement area. be able to.

  Furthermore, since the present embodiment is configured to optically scan with laser light, the optical path length can be increased similarly to the second embodiment. Also in this embodiment, the concentration is lower than that of the first embodiment. Gas can be detected and the lower limit of detection can be lowered.

  FIG. 10 is a schematic top view showing the fourth embodiment of the sheet drying control apparatus 1 according to the present invention. The same elements as those of the first embodiment in FIG. 2 are denoted by the same reference numerals, description thereof is omitted, and only different portions will be described.

  In general, a plurality of drying blocks, which are areas for drying sheets formed by the casing 10 of the drying apparatus main body 3, are provided along the sheet conveyance direction in the casing 10. In the present embodiment, as shown in FIG. 10, for example, a case where the block is divided into three drying blocks (first drying block 10A, second drying block 10B, and third drying block 10C) will be described.

  In order to control the drying operation of the drying apparatus main body 3 having a plurality of drying blocks as described above for each drying block, the sheet drying control apparatus 1 in this embodiment is, for example, the first embodiment as shown in FIG. The light projecting control unit 4 and the light receiving unit 5 as well as the drying control unit 6 shown in FIG. 4 are divided into the first light projecting control unit 4A, the second light projecting control unit 4B, the third light projecting control unit 4C, The first light receiving unit 5A, the second light receiving unit 5B, the third light receiving unit 5C, and the first drying control unit 6A, the second drying control unit 6B, and the third drying control unit 6C are arranged.

  Further, the configuration in the present embodiment includes a central control unit 24 that presets the target value of the volatile gas component concentration for each drying block. In addition to setting the target value for the volatile gas component concentration, the central control unit 24 stores data such as the drying action intensity corresponding to various printing conditions and the target value for the volatile gas component concentration, and is selected by the operator. The intensity of each drying action corresponding to the printing conditions and the wavelength of the laser beam to be projected can be commanded to each projection control unit, and the concentration and target value of the volatile gas component measured for each drying block can be specified. It is configured to output a control signal for adjusting the strength of the action of drying the sheet by comparing and determining the drying state to each drying control unit. In addition, what is necessary is just to adjust the intensity | strength of at least any one of the conveyance part 7, the heat generating part 8, and the ventilation part 9 in adjusting the intensity | strength of a drying effect | action.

  FIG. 11 shows the sheet transport distance D (see FIG. 10) and the concentration of volatile solvent remaining on the sheet (solvent residual concentration) when the drying apparatus body 3 is controlled by the sheet drying control apparatus 1 according to the present embodiment. It is explanatory drawing explaining the fall state.

  Here, the residual solvent concentration before entering the drying apparatus main body 3 is larger than the residual solvent concentration that is allowed to remain in the dry quality standard (hereinafter referred to as “solvent residual allowable concentration Co”). For example, the sheet 2 coated with a volatile solvent in the printing process or the like is dried to a solvent residual allowable concentration Co or less at a predetermined drying speed as a drying action is obtained in each drying block. Generally, the residual solvent concentration before entering the first drying block is about 1% (10000 ppm), and the allowable residual solvent concentration Co is 20 ppm or less, although it varies depending on, for example, the printing business operator and printed matter. The sheet 2 is dried at a predetermined speed, and the drying speed varies depending on the strength of the drying action. The volatile gas component concentration measured by the sheet drying control apparatus 1 according to the present embodiment can be treated as an index indicating the actual drying speed when a drying action having a predetermined strength is given. .

  By the way, in the conventional measurement by the above-mentioned FT-IR etc., for example, as shown in FIG. 11, the solvent residual concentration is measured by batch measurement at a location (shown by a circle) taken out from the drying apparatus main body 3. It was estimated based on the volatile gas component concentration. Therefore, the drying in the drying apparatus main body 3 is a drying in which the solvent residual concentration changes at a constant slope (that is, a constant drying speed) as shown by a dotted line in FIG. It was not known whether the concentration was drastically reduced at the beginning or end of the drying process (ie, the drying rate increased rapidly at the beginning or end). It should be noted that the optimum drying method in which the residual solvent concentration changes is generally different depending on the type of sheet to be dried.

  The sheet drying control apparatus 1 according to the present embodiment sets a target value of the volatile gas component concentration for each drying block, and sets the volatile gas component concentration for each drying block, for example, at a location shown in FIG. ), The drying operation of the drying apparatus main body 3 can be controlled so that the concentration of the volatile gas components measured and measured by the light projection control units 4A, 4B, and 4C approaches the target value for each drying block. Control can be performed so that a predetermined drying speed is obtained every time. Therefore, for example, as shown by the dotted line in FIG. 11, the drying operation can be performed at a constant drying speed, and as shown by the alternate long and short dash line, the drying speed suddenly increases at the initial stage or the end of the drying process. Also, a drying operation can be performed.

  By the way, in this embodiment, a drying action having a predetermined strength can be given to each drying block, but the result (drying degree) of each drying action often appears on the sheet delivery side of each drying block.

  In the present embodiment, as shown in FIGS. 10 and 11, the light projecting control unit 4 and the light receiving unit 5 are respectively arranged so as to be able to measure the concentration of volatile gas components on the terminal end side in the sheet conveying direction in each drying block. It is. Thereby, in the structure in this embodiment, the result of the drying effect | action for every drying block can be represented accurately. However, it is not realistic to project or receive light at a location 0 mm from the end of each drying block, and is preferably within 50 mm from the end, for example, from the end of each drying block. It is desirable that the distance to the location where the light is received is, for example, within 5% of the transport distances D1, D2, and D3 (see FIG. 10) for each drying block. In the first to third embodiments described above, the light projection control unit 4 and the light receiving unit 5 may be arranged so that the volatile gas component concentration on the terminal end side in the sheet conveyance direction can be measured.

  In the present embodiment, the measurement unit is configured to include each of the light projection control units 4A, 4B, and 4C and each of the light receiving units 5A, 5B, and 5C, and the control unit includes the central control unit 24 and each drying unit. The controller 6A, 6B, 6C is provided.

  Further, in the above description, the central control unit 24 performs operations such as storing the strength of the drying action and data of each target value corresponding to various printing conditions, comparing the measurement result with the target value, determining the dry state, and the like. However, the central control unit 24 may not be provided, and for example, a configuration in which the light projection control units 4A, 4B, and 4C and the drying control units 6A, 6B, and 6C are performed may be employed. Furthermore, the configuration described in the other embodiments described above can be applied to each drying block.

  Next, the control operation of the sheet drying control apparatus 1 according to the present embodiment will be described based on FIGS. In addition, description is simplified about the same part as control operation of 1st Embodiment. In the following description, for example, in the first drying block 10 </ b> A and the second drying block 10 </ b> B, the sheet drying control apparatus 1 has a strength corresponding to a predetermined printing condition (for example, ink application amount) or the like (for example, the heating unit). The concentration of the volatile gas component when the drying action is given to the sheet 2 by the temperature, the blowing amount, the conveying speed, etc.) is measured in advance, and this concentration is set as the target value. Further, in the third drying block 10C, as in the first embodiment, the drying is such that the volatile gas component allowable concentration determined according to the type of the sheet 2 is set as the target value, and the target value is measured on the terminal end side. It is assumed that the strength of the action is obtained in advance by experiments or the like for each type of sheet 2. The initial data created for each drying block will be described, for example, as already stored in the memory in the central control unit 24 and the creation of the initial data (step S11) has been completed.

  First, initial data corresponding to a printing condition selected by an operator or the like is read from the memory in the central control unit 24 (step 12). Next, based on the initial data, the central control unit 24 assigns the strength of the drying action to each drying control unit (the first drying control unit 6A, the second drying control unit 6B, and the third drying control unit 6C) for each block. Based on this command, each drying control unit starts the drying operation of the drying apparatus body 3 with a predetermined strength of drying action for each drying block. At the same time, the central control unit 24 controls the wavelength and output of the laser light by each light projection control unit (the first light projection control unit 4A, the second light projection control unit 4B, and the third light projection control unit 4C). (Step S13). Further, each light projecting control unit and light receiving unit measure the volatile gas component concentration (step S14) by the same method as in the first embodiment, and output the measurement result to the central control unit 24 (step S15). Then, the central control unit 24 determines whether the volatile gas component concentration of each drying block is within the allowable range of the target value, and applies the same drying to the drying control unit of the drying block determined to be within the allowable range. A command to perform a drying operation with the intensity of action is output, and the drying block is returned to step S14 and measured again (step S16). If the measured volatile gas component concentration is outside the allowable range, the process proceeds to the next step S17 for the first drying block 10A and the second drying block 10B, and the process proceeds to the next step S18 for the third drying block 10C. move on. Finally, as step S17, for the first drying block 10A and the second drying block 10B, the central control unit 24 determines that it is difficult to dry when the measured value is lower than the lower limit value of the allowable range, and the volatile gas. A control signal for increasing the intensity of the drying action by a predetermined amount is output to the corresponding drying control unit so that the component concentration approaches the target value. In addition, when the measured volatile gas component concentration is higher than the upper limit value of the allowable range, the central control unit 24 determines that the volatile gas component concentration is easy to dry, and the strength of the drying action so that the volatile gas component concentration approaches the target value. Is output to a corresponding drying control unit (step S17). Moreover, about 3rd drying block 10C, the same determination as step 5 demonstrated in 1st Embodiment is performed as step S18, and a control signal is output to a drying control part according to a determination result (step S18). And the drying operation | movement to said step S14-S18 is performed for every drying block until it reaches predetermined time.

  With such a configuration, the sheet drying control apparatus 1 according to the present embodiment can control the drying operation of the drying apparatus main body 3 so that a predetermined drying action strength can be obtained for each drying block. Therefore, for example, according to the type of sheet to be dried, the drying operation of the drying apparatus main body 3 can be controlled with the optimum strength of the drying action for each drying block.

Next, an embodiment of a drying control method according to the present invention will be described with reference to the drawings.
FIG. 5 is also a flowchart showing an embodiment of the drying control method according to the present invention. 1 and 2 are also schematic diagrams illustrating an example of a sheet drying apparatus that uses the drying control method according to the present embodiment.

  The drying control method according to the present embodiment includes a drying block (indicating an area for drying a sheet formed by the casing 10) for drying the sheet 2 by volatilizing the solvent contained in the sheet 2 while conveying the sheet 2. In this method, the drying operation for drying the sheet 2 of the drying apparatus main body 3 is controlled according to the procedure described below.

  In the drying control method according to the present embodiment, as shown in FIG. 5, first, for example, the above-described initial data is created in advance, predetermined printing conditions are selected, and drying of the drying apparatus main body 3 is performed based on the selected conditions. The operation is started (steps S1 and S2). Then, laser light having a wavelength in the infrared region is projected to the volatile region 12 of the gas that volatilizes from the sheet 2 in the drying block, the laser beam that passes through the volatile region 12 of the gas is received, and the received light intensity of the received laser beam Based on the above, the volatile gas component concentration of the gas volatile from the sheet 2 in the gas volatile region 12 is measured (step S3). Further, it is determined whether the measured volatile gas component concentration is within an allowable range of the volatile gas component concentration set in advance according to the selected printing condition, for example (step S4). If it is within the allowable range, the process returns to step S3 and remeasures, and the drying apparatus body 3 is dried with the same strength of drying action. Further, when the value is higher than the upper limit value of the allowable range, for example, the strength of the drying action is decreased by a predetermined amount, and when the value is lower than the lower limit value of the allowable range, the strength of the drying action is increased by a predetermined amount (step S5). ). And the drying operation | movement to said step S3-S5 is performed until it reaches | attains predetermined time. In this way, the drying operation is controlled by adjusting the strength of the action of drying the sheet 2 in the drying apparatus main body 3 based on the volatile gas component concentration.

  With such a configuration, the drying control method according to the present embodiment measures the volatile gas component concentration of the gas from the sheet 2 to determine the volatilization state of the gas, and performs the drying operation of the drying apparatus body 3 according to the determination result. By controlling, the result (drying degree) of the drying action by the drying apparatus main body 3 can be directly managed quantitatively. In this way, it is possible to provide a drying control method for improving the quality control in the drying process of the sheet 2 and improving the drying quality to dry the sheet.

Next, an embodiment of a sheet drying apparatus according to the present invention will be described with reference to the drawings.
FIG. 1 is also a schematic configuration diagram showing an embodiment of a sheet drying apparatus according to the present invention. Similarly, FIG. 2 is also a schematic top view of the sheet drying apparatus of the present embodiment.

  In FIG. 1, a sheet drying apparatus 25 according to this embodiment includes a drying apparatus body 3 having a drying block that volatilizes a solvent contained in the sheet while drying the sheet and dries the sheet, and a sheet of the drying apparatus body 3. For example, the sheet drying control apparatus 1 according to the first embodiment described above is controlled, and the sheet drying control apparatus 1 controls the drying operation of the drying apparatus body 3 to dry the sheet. Has been. The sheet drying control device 1 is not limited to this, and all the sheet drying control devices 1 of the other embodiments described above can be applied. Further, the drying apparatus main body 3 can be applied to all the drying apparatus main bodies 3 of the other embodiments described above, and is not limited to these, and a drying block that volatilizes the solvent contained in the sheet and dries the sheet while conveying the sheet. And the drying apparatus main body 3 having a configuration capable of controlling the strength of the drying action from the sheet drying control apparatus 1.

  With such a configuration, the sheet drying apparatus 25 according to the present embodiment directly and quantitatively manages the effect of the drying operation in the drying apparatus body 3 by the sheet drying control apparatus 1, and the drying quality in the drying process of the sheet 2. It is possible to provide a sheet drying apparatus 25 that improves the management accuracy, improves the drying quality, and dries the sheet.

  In all the descriptions above, the drying apparatus main body 3 has been described as a single unit. However, the drying apparatus main body 3 is not limited to a single unit, and a plurality of drying apparatus main bodies 3 may be arranged side by side. In addition, the light projecting unit 13 has been described as projecting one wavelength of laser light. However, the light projecting unit 13 is not limited to a single wavelength. It is good also as a structure which can each detect the reflected light of the laser beam of each wavelength. Further, when the light receiving unit 5 has such a configuration, the laser oscillation unit 16 may be configured to be capable of simultaneously oscillating laser beams having a plurality of wavelengths.

DESCRIPTION OF SYMBOLS 1 Sheet drying control apparatus 2 Sheet 3 Drying apparatus main body 4 Light projection control part 5 Light receiving part 6 Drying control part 11 Measuring device control part 12 Volatile gas area 13 Light projection part 22 Reflecting mirror 23 Retroreflector 24 Central control part 25 Sheet drying apparatus

Claims (20)

In the sheet drying control apparatus that controls the drying operation of the drying apparatus main body having a drying block that volatilizes the solvent contained in the sheet while drying the sheet to dry the sheet,
Measuring means for measuring the volatile gas component concentration of the gas that volatilizes from the sheet with laser light having a wavelength in the infrared region,
Control means for controlling the drying operation by adjusting the strength of the action of drying the sheet in the drying apparatus main body based on the volatile gas component concentration measured by the measuring means;
A sheet drying control apparatus comprising:   The measuring means includes: a light projecting unit that projects laser light of an infrared wavelength to a volatile region of gas that is volatilized from a sheet in the drying block; and a light receiving unit that receives laser light transmitted through the gas volatile region. 2. The sheet drying control apparatus according to claim 1, further comprising: measuring a volatile gas component concentration of a gas that volatilizes from the sheet in the gas volatilization region based on a light reception intensity of the light receiving unit.   The control means adjusts the strength of the action of drying the sheet in the main body of the drying device so that the volatile gas component concentration measured by the measuring means approaches a target value of the volatile gas component concentration set in advance. The sheet drying control apparatus according to claim 1 or 2, wherein a drying operation is controlled.   A plurality of the drying blocks are provided along the sheet conveying direction in the drying apparatus main body, the measuring means is arranged for each drying block, and the control means sets the target value of the volatile gas component concentration. 4. The method according to claim 1, wherein the drying operation is controlled for each drying block by setting in advance for each drying block and adjusting an intensity of an action of drying the sheet in the drying apparatus main body. The sheet drying control apparatus according to one.   5. The sheet drying control apparatus according to claim 1, wherein the measurement unit is arranged to measure the volatile gas component concentration on the terminal end side in the sheet conveyance direction in the drying block. .   The sheet drying control apparatus according to claim 1, wherein the measuring unit is configured to be capable of optically scanning the laser beam within the drying block.   The sheet drying control apparatus according to any one of claims 1 to 6, wherein a gas to be measured by the measuring unit contains a volatile organic compound as a main component.   The sheet drying control apparatus according to any one of claims 1 to 6, wherein a gas to be measured by the measuring unit contains water as a main component.   9. The sheet drying control apparatus according to claim 1, wherein the light projecting unit and the light receiving unit are disposed to face each other with the volatilization region interposed therebetween.   The measuring means includes a reflecting mirror that reflects the laser light that passes through the volatile region, and the light projecting unit and the light receiving unit are arranged to face the reflecting mirror and sandwich the volatile region. The sheet drying control device according to any one of claims 1 to 9, wherein   The sheet drying control apparatus according to claim 10, wherein the reflecting mirror is configured to be able to adjust a light receiving intensity of the laser light in the light receiving unit by adjusting an optical axis of the reflected laser light.   The sheet drying control apparatus according to claim 10, wherein the reflecting mirror is a retroreflector.   The sheet drying control apparatus according to any one of claims 1 to 12, wherein a wavelength of the laser light projected from the light projecting unit is a wavelength in a mid-infrared region. A drying control method for controlling a drying operation of a drying apparatus main body having a drying block for volatilizing a solvent contained in the sheet and drying the sheet while conveying the sheet,
The volatile gas component concentration of the gas volatile from the sheet in the drying block is measured by a laser beam having an infrared wavelength, and the sheet in the drying apparatus main body is dried based on the measured volatile gas component concentration. A drying control method, wherein the drying operation is controlled by adjusting the strength.   The laser beam having the wavelength in the infrared region is projected onto the volatile region of the gas that volatilizes from the sheet in the drying block, the laser beam transmitted through the volatile region of the gas is received, and the received light intensity of the received laser beam is increased. The drying control method according to claim 14, wherein a volatile gas component concentration of a gas volatile from a sheet in the gas volatile region is measured based on the volatile gas component concentration.   The drying operation is controlled by adjusting the strength of the action of drying the sheet in the drying apparatus main body so that the measured volatile gas component concentration approaches a target value of a preset volatile gas component concentration. The drying control method according to claim 14 or 15.   A plurality of the drying blocks are provided along the sheet conveying direction in the drying apparatus main body, the volatile gas component concentration of the gas is measured for each drying block, and the target value of the volatile gas component concentration is previously set for each drying block. The drying according to any one of claims 14 to 16, wherein the drying operation is controlled for each drying block by setting and adjusting the strength of the action of drying the sheet in the drying apparatus main body. Control method.   18. The drying according to claim 14, wherein the volatile gas component concentration is measured by measuring the volatile gas component concentration on a terminal end side in a sheet conveying direction in the drying block. Control method.   The drying control method according to any one of claims 14 to 18, wherein the volatile gas component concentration is measured by optically scanning the laser beam in the drying block. The sheet drying control device according to any one of claims 1 to 13,
A drying apparatus main body having a drying block for drying the sheet by volatilizing the solvent contained in the sheet while conveying the sheet;
With
A sheet drying apparatus that controls a drying operation of the drying apparatus main body by the sheet drying control apparatus to dry the sheet.

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