JP2019162773A - Drying device and liquid discharge device - Google Patents

Abstract

To prevent a rise in temperature of a medium.SOLUTION: A drying device has a first heating part that approaches or contacts a medium to heat the medium, a second heating part that heats a liquid application face formed on the medium in a non-contact manner, a temperature detection unit that detects the temperature of the medium, and a first heating control unit that controls to reduce the temperature of heating by the first heating part, when the detected medium temperature is equal to or higher than a first temperature.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a drying device and a liquid ejection device.

  In an inkjet printer, a high-boiling point solvent is contained in the aqueous pigment ink to prevent the ink from drying in the head. In addition, in an ink jet printer, an image is optimized and fixed on a medium by drying ink ejected onto the medium. As a method for drying the ink, for example, the ink on the image forming surface is irradiated with infrared rays (IR), the water molecules in the ink or the high-boiling solvent molecules are resonated, and the ink self-heats by molecular vibration, thereby vaporizing.・ There is a technique to evaporate and dry.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2017-128039), an ink containing an infrared absorber that absorbs infrared rays and a solvent that dissolves or decomposes the infrared absorber is ejected onto the medium, and the infrared light source emits the ink on the medium. A technique for volatilizing and removing at least a part of a solvent contained in ink by irradiating the ink with infrared rays is disclosed. Further, in Patent Document 2 (Japanese Patent No. 5772382), an infrared ray having a maximum wavelength within the absorption wavelength band of water contained in the liquid and a liquid contained in the liquid with respect to a recording medium that has been subjected to a recording process by jetting the liquid. A technique for irradiating infrared light having a maximum wavelength within the absorption wavelength band of the solvent is disclosed.

  However, the conventional technique has a problem that it is difficult to prevent a temperature rise of the media. Specifically, although the prior art attempts to efficiently dry the moisture and solvent of the ink ejected onto the medium, there is a possibility that the temperature of the medium itself will increase due to infrared irradiation.

  The present invention has been made in view of the above, and an object thereof is to prevent a temperature rise of a medium.

  In order to solve the above-described problems and achieve the object, a drying apparatus according to the present invention includes a first heating unit that heats the medium in contact with or in proximity to the medium, and a liquid application surface formed on the medium. A second heating unit that heats in a non-contact manner, a temperature detection unit that detects the temperature of the medium, and heating by the first heating unit when the detected temperature of the medium is equal to or higher than the first temperature And a first heating control unit that performs control to lower the temperature.

  According to the present invention, it is possible to prevent an increase in the temperature of the media.

FIG. 1 is a block diagram illustrating a hardware configuration example of the liquid ejection apparatus according to the first embodiment. FIG. 2 is a diagram illustrating a configuration example of a drying unit of the liquid ejection apparatus according to the first embodiment. FIG. 3 is a cross-sectional view of a quartz glass tube heater. FIG. 4 is a block diagram illustrating a functional configuration example of the drying unit according to the first embodiment. FIG. 5 is a diagram illustrating an example of transmittance characteristics with respect to the wavelength of the filter according to the first embodiment. FIG. 6 is a diagram illustrating an example of cooling of the filter according to the first embodiment. FIG. 7 is a diagram for explaining component detection according to the first embodiment. FIG. 8 is a diagram illustrating an example of a component detection result by ejecting ink onto the medium according to the first embodiment and performing FT-IR analysis. FIG. 9 is a diagram for explaining an example of the resonance wavelength of the ink according to the first embodiment. FIG. 10 is a flowchart illustrating an example of a flow of DUTY determination processing according to the first embodiment. FIG. 11 is a diagram for explaining an example of determining DUTY according to the first embodiment. FIG. 12 is a diagram illustrating an example of transmittance characteristics with respect to the wavelength of the filter according to the first embodiment. FIG. 13 is a flowchart illustrating an example of a processing flow by the drying unit of the liquid ejection apparatus according to the first embodiment. FIG. 14 is a flowchart illustrating an example of a processing flow by the drying unit of the liquid ejection apparatus according to the first embodiment. FIG. 15 is a flowchart illustrating an example of a processing flow by the drying unit of the liquid ejection apparatus according to the first embodiment.

  Embodiments of a drying apparatus and a liquid discharge apparatus according to the present invention will be described below with reference to the accompanying drawings. The present invention is not limited to the following embodiments. Moreover, each embodiment can be combined suitably as long as the contents do not contradict each other.

(Embodiment 1)
The hardware configuration of the liquid ejection apparatus 100 according to Embodiment 1 will be described with reference to FIG. FIG. 1 is a block diagram illustrating a hardware configuration example of the liquid ejection apparatus 100 according to the first embodiment.

  As shown in FIG. 1, the liquid ejection apparatus 100 includes a control unit 101. Further, the liquid ejection apparatus 100 includes a CPU (Central Processing Unit) 102 that controls the entire apparatus. The liquid ejecting apparatus 100 has a ROM (Read Only Memory) 103, a RAM (Random Access Memory) 104, a nonvolatile memory (NVRAM: Non-Volatile RAM) 105, and an ASIC (Application Specific Integrated Circuit). 106 is connected.

  The ROM 103 stores programs executed by the CPU 102 and other fixed data. The RAM 104 temporarily stores image data and the like. The nonvolatile memory 105 holds data even while the power of the liquid ejection apparatus 100 is shut off. The ASIC 106 processes input / output signals for controlling the entire apparatus, image processing for performing various signal processing, rearrangement, and the like.

  The control unit 101 includes an I / F 107, a print control unit 108, a main scanning motor driving unit 109, a sub scanning motor driving unit 110, a heater control unit 111, and an I / O 112. In addition, the control unit 101 connects the operation panel 113, the environment sensor 114, and the component detection unit 115.

  The I / F 107 is an interface that transmits and receives data and signals to and from the host side. Specifically, the I / F 107 receives print data or the like generated by a host printer driver such as an information processing apparatus, an image reading apparatus, or an imaging apparatus via a cable or a network. That is, the print data generation output for the control unit 101 may be performed by a host-side printer driver. The CPU 102 reads and analyzes the print data in the reception buffer included in the I / F 107. The ASIC 106 performs image processing, data rearrangement processing, and the like, and the image data is transferred to the print control unit 108 and the head driver 116.

  The print control unit 108 generates a drive waveform for driving the liquid discharge head 121, and image data for selectively driving a pressure generating unit that generates pressure for the liquid discharge head 121 to discharge liquid from the nozzles. The accompanying various data is output to the head driver 116.

  The print control unit 108 may have a computer configuration including a CPU, a ROM, a RAM, and the like. The print control unit 108 exhibits a desired function when the CPU executes a program stored in a ROM or the like.

  The program executed by the CPU of the print control unit 108 is an installable or executable file and can be read by a computer such as a CD-ROM, flexible disk (FD), CD-R, or DVD (Digital Versatile Disk). The recording medium may be recorded and provided.

  Furthermore, the program executed by the CPU of the print control unit 108 may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. The program executed by the CPU of the print control unit 108 may be provided or distributed via a network such as the Internet.

  The main scanning motor driving unit 109 drives the main scanning motor 117. The main scanning motor 117 is driven to move the carriage 120 including the liquid ejection head 121 in the main scanning direction. The sub scanning motor driving unit 110 drives the sub scanning motor 118. The sub-scanning motor 118 operates the conveyance member 122 that conveys a medium or the like that is a liquid discharge target by the liquid discharge head 121 by driving. The heater control unit 111 controls the heater 119. In the present embodiment, the heater 119 corresponds to a media heater 119a, an infrared heater 119b, and the like which will be described later. The media heater 119a adjusts the temperature of the media. The infrared heater 119b is dried by radiating infrared rays to the ink on the medium.

  The I / O 112 acquires information from the environment sensor 114 and the component detection unit 115 and extracts information necessary for controlling each unit of the liquid ejection apparatus 100. For example, the environmental sensor 114 detects environmental temperature, environmental humidity, and the like. Further, the component detection unit 115 detects the component of the ink ejected on the medium. The I / O 112 also inputs information from various sensors other than the environmental sensor 114 and the component detection unit 115. The operation panel 113 inputs and displays various information.

  Here, an outline of the print control process in the liquid ejection apparatus 100 will be described.

  The CPU 102 of the liquid ejecting apparatus 100 reads and analyzes the print data in the reception buffer of the I / F 107, performs necessary image processing, data rearrangement processing, and the like in the ASIC 106 and transfers them to the print control unit 108.

  The print control unit 108 outputs image data and a drive waveform to the head driver 116 at a required timing. More specifically, the print control unit 108 performs D / A conversion and amplification of the drive pulse pattern data stored in the ROM 103 and read by the CPU 102, thereby driving the drive pulse configured by one drive pulse or a plurality of drive pulses. Generate a waveform.

  Note that generation of image data (for example, dot pattern data) for image output may be performed by storing font data in the ROM 103, for example, or by developing the image data into a bitmap by a host-side printer driver. You may make it transfer to the liquid discharge apparatus 100. FIG.

  The head driver 116 selectively applies a driving pulse constituting a driving waveform supplied from the print control unit 108 to the pressure generating unit of the liquid ejection head 121 based on input image data (for example, dot pattern data). The liquid discharge head 121 is driven by applying the voltage.

  Here, the occurrence of cockling due to thermal expansion will be described. When the media is heated suddenly by drying, the media on the platen may wave (cockling) due to thermal expansion of the media, and the media may rub against the liquid ejection head 121 or jam may occur. Further, due to the thermal expansion of the medium on the platen, the ink landing position is shifted by an error generated by the expansion. If such an error occurs due to drying between colors, it may be resolved by cooling the media or performing alignment between colors, but adjustment of the dot position is adjusted by feedback control. In order to do so, the size of the apparatus becomes large by adding a reader, a cooling device, or the like.

  In this embodiment, since only the ink is heated and dried without heating the medium, it is possible to reduce the thermal expansion of the medium and suppress the deviation of the landing position. Therefore, image quality and conveyance quality can be improved by reducing cockling. In the present embodiment, the host-side PC holds control information related to media. As the control information related to the media, for example, parameter values such as an ICC profile, heater control conditions (for example, temperature control value, output wavelength, drying time, etc.), ink limiter, media feed amount, and the like are stored. In the PC on the host side, various setting conditions for printing include parameter data relating to drying, IR wavelength characteristics and IR intensity data corresponding to the media, and the infrared heater 119b is set according to the parameters relating to drying. Be controlled.

  FIG. 2 is a diagram illustrating a configuration example of the drying unit 150 of the liquid ejection apparatus 100 according to the first embodiment. The drying unit 150 corresponds to a “drying device”.

As shown in FIG. 2, the drying unit 150 of the liquid ejection apparatus 100 includes an environmental sensor 114, a component detection unit 115, a media heater 119a, an infrared heater 119b _1, and an infrared heater 119b ₂ . The irradiated surface of the infrared heater 119b _1, the filter 125A is installed. The irradiated surface of the infrared heater 119b _2, the filter 125B is installed. In the case where the infrared heater 119b ₁ and the infrared heater 119b ₂ are not distinguished, they are referred to as an infrared heater 119b. Similarly, when the filters 125A and 125B are not distinguished, they are called filters 125. Further, the number of the environmental sensor 114, the component detection unit 115, the infrared heater 119b, and the filter 125 is not limited to the illustrated number.

  The media heater 119a is a heater for adjusting the temperature of the media. The media heater 119a corresponds to a “first heating unit”. The infrared heater 119b is a heater for radiating infrared rays to the ink on the medium and drying it. The infrared heater 119b corresponds to a “second heating unit”. The filter 125 restricts the passage of infrared rays radiated by the infrared heater 119b. The environmental sensor 114 and the component detection unit 115 detect temperature and ink components at each position.

  FIG. 3 is a cross-sectional view of a quartz glass tube heater. As shown in FIG. 3, when the infrared heater 119b is a quartz glass tube heater (far infrared), the filament is formed of a nichrome wire. The nichrome wire is heated to 700 ° C. to 800 ° C. and generates infrared light having a peak wavelength of 3 μm. Quartz glass does not transmit infrared light having a wavelength of 3.5 μm or more. For this reason, infrared rays of less than 3.5 μm generated from the nichrome wire are radiated from the nichrome wire through the glass tube. Thereafter, the surface of the quartz glass tube is heated to 200 ° C. to 400 ° C. by the nichrome wire inside the glass tube, and infrared rays of 4 μm to 6 μm are generated from the surface of the glass tube. In the present embodiment, the filter 125 is used to manage the wavelength at which infrared rays pass, and the infrared rays are radiated from the infrared heater 119b to the ink on the medium.

  The filter 125 uses various infrared transmitting materials for the substrate, forms a non-absorbing multilayer film by vacuum deposition, and transmits only an arbitrary wavelength by interference of the thin film. That is, the filter 125 transmits only a specific wavelength.

  FIG. 4 is a block diagram illustrating a functional configuration example of the drying unit 150 according to the first embodiment.

  As shown in FIG. 4, the drying unit 150 includes a media heater control unit 151 and an IR heater control unit 152.

  The media heater control unit 151 controls heating by the media heater 119a. The media heater control unit 151 corresponds to a “first heating control unit”. For example, when the temperature of the medium detected by the environment sensor 114 is equal to or higher than the first temperature (for example, 60 ° C. or higher), the media heater control unit 151 performs control to lower the heating temperature by the media heater 119a. Further, for example, the media heater control unit 151 performs control to lower the heating temperature by the media heater 119a when the infrared resonance wavelength of the media and ink is within a predetermined range.

  The IR heater control unit 152 controls heating by the infrared heater 119b. The IR heater control unit 152 corresponds to a “second heating control unit”. For example, the IR heater control unit 152 performs control to lower the heating temperature by the infrared heater 119b when the temperature of the ink is equal to or higher than the second temperature (for example, 80 ° C. or higher). For example, the IR heater control unit 152 performs control to lower the heating temperature by the infrared heater 119b when the infrared resonance wavelength of the medium and the ink is within a predetermined range. For example, the IR heater control unit 152 performs control to increase the heating temperature by the infrared heater 119b when the absorbance of the ink component and the absorbance in the dry state of the ink are not within a predetermined range.

  FIG. 5 is a diagram illustrating an example of transmittance characteristics with respect to the wavelength of the filter 125 according to the first embodiment. In FIG. 5, the vertical axis represents the transmittance, and the horizontal axis represents the wavelength.

  As shown in FIG. 5, a filter A1 (shown by a broken line) that is one of the filters 125 is a filter that transmits infrared rays having a wavelength of less than 3.2 μm and blocks infrared rays having a wavelength of 3.2 μm or more. A filter A2 (shown by a solid line), which is one of the filters 125, is a filter that transmits infrared light having a wavelength of 2.8 μm or more and blocks infrared light having a wavelength of less than 2.8 μm. By stacking such filters, it is possible to make a filter that transmits only infrared rays having a wavelength of 2.8 μm to 3.2 μm and blocks infrared rays other than this wavelength.

  FIG. 6 is a diagram illustrating an example of cooling of the filter 125 according to the first embodiment.

  For example, since the lamp of the infrared heater 119b is provided in the vicinity of the filter 125, infrared rays are emitted from the filter 125 when the temperature of the filter 125 rises. For this reason, as shown in FIG. 6, in order to suppress the temperature rise of filter 125 itself, you may cool so that it may maintain at a room temperature state by flowing air.

  FIG. 7 is a diagram for explaining component detection according to the first embodiment.

  Organic substances are mainly composed of carbon, oxygen, and hydrogen, and it is difficult to identify substances from elemental analysis. The physical properties change depending on how these constituent elements are connected. When specifying organic substances, how to combine elements is important. As a method for analyzing how elements are combined, there is FT-IR (Fourier transform infrared spectroscopy) analysis. This analysis method utilizes the fact that organic substances have absorption in the infrared region, and this absorption is derived from the molecular structure. The following description will be given on the assumption that the molecule shown in FIG. 7 (which schematically shows the molecular structure) exists.

  Organic substances include combinations of elements such as alcohols and ethers and bonding states. The connection method between the portions surrounded by the solid line, the broken line, and the alternate long and short dash line shown in FIG. 7 corresponds to the combination of the combined states. When the organic material is irradiated with infrared light, the absorbed infrared light is different for each connection method. Therefore, if the infrared light is divided and irradiated and the absorption ratio at that time is determined, it is possible to estimate what kind of binding molecules exist.

  FIG. 8 is a diagram illustrating an example of a component detection result by ejecting ink onto the medium according to the first embodiment and performing FT-IR analysis. In FIG. 8, the vertical axis represents absorbance (or transmittance), and the horizontal axis represents wave number.

The wave number is a value corresponding to the wavelength of the irradiating infrared light. The wavelength is usually indicated by a unit of length (μm), but in FT-IR analysis, it is often expressed by its reciprocal. The wave number is used because the energy of light is proportional to the reciprocal of the wavelength (wave number). The unit of wave number is represented by “cm ⁻¹ ” and is called “Kaiser”.

  Absorbance is a value indicating how much the light hit is transmitted or reflected and the intensity is weakened. The transmittance is a value indicating how much the incident light is transmitted. If there is no absorption, the transmittance is 100%.

FIG. 8 shows an example of the results of FT-IR analysis when ink is ejected onto a vinyl chloride (vinyl chloride) medium and dried. As shown in FIG. 8, 3300 cm around ^-1, 1650 cm around ^-1, absorption was observed at around 1100 cm ^-1, wave number of the ink component is detected. Further, 2900 cm around ^-1, 1730 cm around ^-1 wavenumber of around 1250 cm ^-1, the components of the salt Bimedia is detected. From these pieces of information, it is possible to detect the degree of ink drying when using the vinyl chloride media. Thus, different resins show different spectra.

  Here, the resonance wavelength of media using vinyl chloride will be described.

Examples of copolymers with other types of monomers are described below together with their characteristics.
Vinyl chloride / vinyl acetate copolymer The industrialized one has a vinyl acetate content of 5 to 20 percent and has characteristics such as lower molding temperature, higher solubility and higher adhesiveness than PVC homopolymer. . Those having a low vinyl acetate content may be used for flooring sheets and the like. Those having a high vinyl acetate content may be used in paints and the like by utilizing solubility.

Vinyl chloride / ethylene copolymers Copolymers have been industrialized to ethylene contents up to several percent. Thermal stability is high, and moldability is improved by the internal plasticizing effect. In order to identify polyvinyl chloride from the infrared absorption spectrum, characteristic absorption by C-C1 stretching vibration is used. The PVC results of the component analysis by FT-IR, in the vicinity of 3000 cm ^-1 stretching vibration of the main chain of CH2, CH, is bending vibration thereof in the vicinity of 1430 cm ^-1 is observed. Stretching vibration of C-C1 ^{is, 693cm -1, 630cm -1,} is a broad to 620 cm ^-1, appears as strong absorption. Confirmation that a PVC, the ^{620 cm} -1, and 630 cm ^-1, was found to be made by the presence of absorption of 1250 cm ^-1.

Although it is another PVC packaging film, both have characteristic absorption of PVC, and a large absorption due to C = O of the ester group is commonly seen in the vicinity of 1740 cm ⁻¹ . However, it is estimated 1600cm around ^-1, 1300 cm around ^-1, around 200 cm ^-1, the difference of the spectrum in the vicinity of 1100 cm ^-1, a film of the copolymer VC / VAc, and is the PVC containing plasticizer DOP .

  Next, the resonance wavelength of media using polyester will be described.

  Thermoplastic polyesters are made by condensation polymerization of dicarboxylic acids and diols. Polyethylene terephthalate (PET) synthesized from terephthalic acid and ethylene glycol is a representative example, and is widely used as fibers, films, bottles and the like. Polybutylene terephthalate (PBT), which is a general-purpose engineering plastic, has excellent heat resistance and chemical resistance, and is used as a film.

According to the result of FT-IR analysis of PET (tetron thickness 4 μm), the absorption around 3000 cm ⁻¹ is weak. Absorption characteristic of the ester group attached to the aromatic ring is around 1720 cm ⁻¹ (−C═O stretching vibration), 1260 cm ⁻¹ (= C—O stretching vibration), 1120 cm ⁻¹ (C—O stretching) (Vibration), each appears as a broad and strong absorption. In addition, sharp absorption due to C—H bending vibration of the aromatic ring is observed in the vicinity of 1020 cm ⁻¹ and 730 cm ⁻¹ .

These absorptions are all based on terephthalic acid esters, and these absorptions are commonly observed in PBT films. The largest difference between PET and PBT is, 3000 cm around ^-1, and, in the size of around 1450 cm ^-1. In PET, the absorption by CH ₂ is negligible. In PBT CH ₂ are continuous four, appear larger absorption of [nu (CH) with methylene groups in the vicinity of 2950 cm ^-1, also similarly greater absorption of by a methylene group [delta] (CH) in the vicinity of 1450 cm ^-1 Appears.

  FIG. 9 is a diagram for explaining an example of the resonance wavelength of the ink according to the first embodiment. FIG. 9 shows an example in which the medium is vinyl chloride.

  As shown in FIG. 9, for example, components related to drying (evaporation) of ink include water, a high boiling point solvent (first solvent) that prevents evaporation, a film formation accelerator that forms a film on the ink surface by evaporation of water, There is a solvent (second solvent) having a function such as a surfactant. From the FT-IR analysis results of the ink, it was found that the resonance wavelength was 3 μm for water, 9 μm for the first solvent, and 6 μm for the second solvent.

  Next, control of the media heater 119a according to Embodiment 1 will be described.

  The temperature setting of the media heater 119a can be performed by the operation panel 113 of the liquid ejection apparatus 100, the host-side PC, or the like. For example, the heater ON / OFF setting and the temperature setting can be controlled. The cycle (separation) for controlling the ON / OFF of the media heater 119a is 1 second. However, it is not ON or OFF within one cycle, but the ON / OFF state is switched according to the lighting rate (DUTY), or the ON / OFF state is repeated by soft start / stop.

  Control of temperature setting is realized by performing arithmetic processing on detection data obtained by AD conversion of feedback of a temperature detection element such as a thermistor and converting the detection data into data used for temperature control. The period of temperature detection is a period for determining the temperature used for control.

  The period detected by the thermistor is 100 msec, the period detected by the thermopile is 10 msec, the upper and lower 4 points of the detected 10 points are cut, and the remaining 6 points are averaged. Accordingly, the temperature detection cycle in the thermistor is 100 msec, and the temperature detection cycle in the thermopile is 100 msec.

  For temperature detection, the temperature is turned on when the temperature falls below the set temperature, and turned off when the temperature exceeds the set temperature. Although different depending on each heater of the media heater 119a, an upper margin and a lower margin with respect to the target temperature are set in order to determine the ON / OFF DUTY of the heater. Here, a case where the media heater 119a is a preheater, a print heater, a post heater, or a cure heater will be described as an example.

  The preheater and postheater, both of which are aluminum foil heaters, are set to an upper margin of + 2 ° C. and a lower margin of 0 ° C. The print heater and cure heater are set to upper margin + 0.5 ° C. and lower margin −0.5 ° C. That is, when the upper margin is + 0.5 ° C., the lower margin is −0.5 ° C., and the set temperature is 70 ° C., the heater is turned on until the thermistor detection temperature is 69.5 ° C., and 70.5 ° C. Will turn off the heater. Further, when the temperature detected by the thermistor falls to 69.4 ° C., the heater is turned on again.

  The current temperature is compared with the target temperature, one of the following three is determined, and the calculated DUTY is determined. FIG. 10 is a flowchart illustrating an example of a flow of DUTY determination processing according to the first embodiment. FIG. 11 is a diagram for explaining an example of determining DUTY according to the first embodiment. As shown in FIGS. 10 and 11, when “current temperature ≦ (target temperature−lower margin)” (step S101: Yes), DUTY is determined to be 100 percent (step S102). If “current temperature ≦ (target temperature−lower margin)” is not satisfied (step S101: No), it is determined whether “current temperature ≧ (target temperature + higher margin)” (step S103).

  At this time, if “current temperature ≧ (target temperature + higher margin)” (step S103: Yes), DUTY is determined to be 0 percent (step S104). On the other hand, when “current temperature ≧ (target temperature + higher margin)” is not satisfied (step S103: No), it is determined to use the previous DUTY (step S105).

  The infrared heater 119b used in this embodiment is equipped with wavelength control. For example, the infrared heater 119b can be controlled by the filter 125 to a wavelength for mainly heating the ink on the medium, a wavelength for heating the medium, and a wavelength for heating the ink on the medium without heating the medium. For temperature adjustment, for example, the temperature of the media is set to 60 ° C., and the temperature of the ink is set to 80 ° C. That is, the ink is desired to be dried at a higher temperature, but the medium is set to a temperature that can suppress the occurrence of cockling due to thermal expansion. For this reason, the media heater 119a is controlled to be turned on and off, thereby suppressing an excessive temperature rise of the media.

  FIG. 12 is a diagram illustrating an example of transmittance characteristics with respect to the wavelength of the filter 125 according to the first embodiment. In FIG. 12, the vertical axis represents the transmittance, and the horizontal axis represents the wavelength.

  As shown in FIG. 12, the filter 125A, which is one of the filters 125, is a filter that transmits infrared rays having a wavelength of around 3 μm and blocks infrared rays having a wavelength other than around 3 μm. The filter 125B, which is one of the filters 125, is a filter that transmits infrared light having a wavelength of about 6 μm and blocks infrared light having a wavelength other than about 6 μm. The filter 125C, which is one of the filters 125, is a filter that transmits infrared rays having a wavelength of about 9 μm and blocks infrared rays having a wavelength other than about 9 μm.

Here, in the case of vinyl chloride media, since the infrared resonance wavelengths are 3.5 μm, 5.8 μm, and 8 μm, the infrared rays for the vinyl chloride media are blocked. For example, an infrared heater 119b provided with a filter 125A and an infrared heater 119b _1, the infrared heater 119b provided with the filter 125B and the infrared heater 119b _2, the infrared heater 119b provided with a filter 125C and an infrared heater 119b _3. These infrared heaters 119b are difficult to heat the media. Media heater 119a is responsible for media temperature control. When the temperature of the media is low, control for increasing the temperature setting of the media heater 119a may be performed, and when the temperature of the media is high, control for decreasing the temperature setting of the media heater 119a may be performed.

The media heater 119a warms the guide plate from the lower surface of the guide plate before printing. Thereby, the medium is warmed by contact heating (heat transfer) by the guide plate. In addition, when ink is landed on the medium, the spreading method of the ink varies depending on the temperature of the medium surface. Therefore, in order to stabilize the dot size (dot gain), the temperature setting of the media heater 119a is controlled. To raise the temperature of the ink, an infrared heater 119b _1, realized by infrared radiant heating from infrared heater 119b ₂ and infrared heater 119b _3. As described above, each infrared heater 119b is provided with a filter 125 that does not include the infrared resonance wavelength of the media. For this reason, it becomes possible to heat only an ink component and to suppress heating of a medium. After the ink component is heated, the dry state of the ink is measured by FT-IR analysis, and the outputs of the infrared heater 119b ₁ , infrared heater 119b ₂ and infrared heater 119b ₃ are controlled based on the evaporation state of moisture and solvent. Therefore, it is possible to stabilize the dry quality.

  FIG. 13 is a flowchart illustrating an example of a processing flow by the drying unit 150 of the liquid ejection apparatus 100 according to the first embodiment. In the process shown in FIG. 13, the temperature is measured by each environmental sensor 114, and each infrared heater 119b is turned on and off.

  As shown in FIG. 13, the liquid ejection apparatus 100 measures the surface temperature of the medium by the environment sensor 114 (step S201). Further, the liquid ejecting apparatus 100 measures the surface temperature of the ink on the medium by the environment sensor 114 (step S202). Then, the liquid ejection apparatus 100 determines whether the surface temperature of the medium is less than 60 ° C. (Step S203).

  At this time, when the surface temperature of the medium is less than 60 ° C. (step S203: Yes), the liquid ejecting apparatus 100 turns on the media heater 119a (step S204). On the other hand, when the surface temperature of the medium is 60 ° C. or higher (step S203: No), the liquid ejecting apparatus 100 turns off the media heater 119a (step S205).

  Subsequently, the liquid ejection apparatus 100 determines whether the surface temperature of the ink is less than 80 ° C. (Step S206). At this time, when the surface temperature of the ink is less than 80 ° C. (step S206: Yes), the liquid ejecting apparatus 100 turns on the infrared heater 119b (step S207). On the other hand, when the ink surface temperature is 80 ° C. or higher (step S206: No), the liquid ejecting apparatus 100 turns off the infrared heater 119b (step S208).

  FIG. 14 is a flowchart illustrating an example of a processing flow by the drying unit 150 of the liquid ejection apparatus 100 according to the first embodiment.

  As shown in FIG. 14, the liquid ejection apparatus 100 measures the media component by the component detection unit 115 (step S <b> 301). Then, the liquid ejection apparatus 100 detects the infrared resonance wavelength of the medium (step S302). Subsequently, the liquid ejecting apparatus 100 determines whether the resonance wavelength of the ink and the medium is included in a predetermined range (Step S303).

  At this time, when the resonance wavelength of the ink and the medium is included in the predetermined range (step S303: Yes), the liquid ejecting apparatus 100 changes the output of the media heater 119a so as not to overheat the medium ( Step S304). Further, the liquid ejecting apparatus 100 changes the output of the infrared heater 119b so that the medium is not heated too much (step S305). On the other hand, when the resonance wavelength of the ink and the medium is not included in the predetermined range (step S303: No), the liquid ejection apparatus 100 ends the process.

  That is, in the liquid ejecting apparatus 100, when the infrared resonance wavelength of the medium and the infrared resonance wavelength of the ink are within a predetermined range, the temperature of the medium may be increased by infrared radiation from the infrared heater 119b. The output of the infrared heater 119b is also changed.

  As the infrared resonance wavelength of the medium, resonance wavelength data registered in advance in the PC on the host side may be used. If the medium is unregistered in the host-side PC, the component detection unit 115 detects the infrared resonance frequency of the medium. In this embodiment, when the infrared resonance frequency of the medium and the infrared resonance frequency of the ink are within a predetermined range, the temperature of the medium is prevented from excessively rising.

  When ink is set in the liquid ejecting apparatus 100, the resonance wavelength corresponding to the ink component is measured in advance, and the wavelength data is input to the PC on the host side. For the medium, when the resonance wavelength at which the temperature of the medium rises is known in advance, the resonance frequency is input to the PC on the host side. When the media materials are different, the media compatibility is further improved by measuring and controlling the wave number of the media itself. In this embodiment, the infrared resonance wavelength of the medium and the infrared resonance wavelength of the ink are compared. If the resonance wavelength is within a predetermined range (substantially coincides), first, the temperature of the media heater 119a is lowered to reduce the media Reduces temperature rise. Further, a media cooling device (not shown) may be operated in order to suppress an increase in the media temperature. In addition, the infrared output of the resonance wavelength is reduced with respect to the infrared heater 119b. At this time, the drying quality may be ensured by reducing the speed at which the medium is conveyed or changing the filter (adjusting the wavelength). If the infrared resonance wavelength of the medium and the ink is not within the predetermined range, the medium heater 119a is initially heated to irradiate the infrared ray having the infrared resonance wavelength of the ink component, and drying is performed.

  FIG. 15 is a flowchart illustrating an example of a processing flow by the drying unit 150 of the liquid ejection apparatus 100 according to the first embodiment.

  As shown in FIG. 15, the liquid ejection apparatus 100 measures the ink components by the component detection unit 115 (step S <b> 401). Then, the liquid ejection apparatus 100 detects the infrared resonance wavelength of the ink component (step S402). Subsequently, the liquid ejecting apparatus 100 determines whether the absorbance of the ink component and the absorbance in the dry state of the ink are within a predetermined range (step S403).

  At this time, when the absorbance of the ink component and the absorbance in the dry state are not within the predetermined range (step S403: No), the liquid ejecting apparatus 100 determines that the ink is insufficiently dried, and the infrared heater is used to further dry the ink. The output of 119b is changed (step S404). On the other hand, when the absorbance of the ink component and the absorbance in the dry state are within the predetermined range (step S403: Yes), the liquid ejection apparatus 100 ends the process assuming that the drying is sufficient.

  In order to judge the dry state of the ink, the absorbance of the wave number of water and various solvents contained in the ink component is obtained and compared with the absorbance at the time of drying (when completely dried). As a result, the control is performed to increase the output of the infrared heater 119b having a wavelength at which the absorbance is not within the predetermined range and drying is determined to be insufficient. The peak wavelength of the infrared wavelength is determined by the temperature of the filament that generates the infrared light. In the present embodiment, far infrared rays having a wavelength of 3 μm to 10 μm are used.

  Infrared rays have a resonance frequency of water molecules and solvents in multiples of 3 μm. In the present embodiment, first, the moisture of the ink is blown, and the film formation accelerator is used to form a film on the ink surface by reducing the moisture, and at the same time, the solvent is also blown off. Since the frequency effective for water evaporation and the frequency effective for the solvent are different, the output of the filament is controlled by the input voltage control so that the temperature of the filament has a peak value of each effective frequency. Thereby, the drying degree of water and a solvent is controlled, and efficient drying is realizable. “Peak wavelength = 0.029 / T (absolute temperature)”. Since the radiant energy is proportional to the fourth power of T, the radiant energy increases as the voltage is increased to increase the filament temperature.

  In this embodiment, since the analysis of the ink component immediately after drying can be performed, the analysis result of the ink component immediately after drying is compared with the analysis result when the ink has been completely dried in advance. In the case of this embodiment, the absorbances of water: 3 μm, first solvent: 9 μm, and second solvent: 6 μm are compared to determine which component is insufficiently dried. The drying quality can be stabilized by increasing the output of the infrared heater 119b having a wavelength that is insufficiently dried.

  As described above, the liquid ejecting apparatus 100 controls to lower the temperature of the media heater 119a when the temperature of the media reaches a predetermined value or higher (for example, 60 ° C. or higher) during the irradiation of infrared rays that heat the ink components. To do. As a result, the liquid ejecting apparatus 100 can prevent the temperature of the medium from rising.

  In addition, since the liquid ejection apparatus 100 includes the filter 125 that blocks the infrared resonance wavelength of the medium and transmits the infrared resonance wavelength of the ink between the infrared heater 119b and the medium, the temperature rise of the medium can be prevented. Can do.

  In addition, the liquid ejection device 100 performs control to lower the temperature of the media heater 119a and the infrared heater 119b when the infrared resonance wavelength of the medium and the infrared resonance wavelength of the ink are within a predetermined range. Can be prevented.

  Further, the liquid ejection apparatus 100 performs control to increase the temperature of the infrared heater 119b on the assumption that the ink is not sufficiently dried when the absorbance of the ink component and the absorbance in the dry state of the ink are not within the predetermined range. The dry quality can be stabilized.

  Information including processing procedures, control procedures, specific names, various data, parameters, and the like shown in the document and drawings can be arbitrarily changed unless otherwise specified. Each component of the illustrated apparatus is functionally conceptual and does not necessarily need to be physically configured as illustrated. That is, the specific form of the distribution or integration of the devices is not limited to the illustrated one, and all or a part of the distribution or integration is functionally or physically distributed or arbitrarily in any unit according to various burdens or usage conditions. Can be integrated.

  In addition, the liquid discharge apparatus 100 described in the above embodiment is an apparatus that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

  Such a liquid ejecting apparatus 100 can also include means for feeding, transporting, and ejecting a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

  For example, as the liquid ejecting apparatus 100, an image forming apparatus that is an apparatus that ejects ink to form an image on a sheet, or a powder layer in which powder is formed in a layered manner to form a three-dimensional structure (three-dimensional structure). There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid.

  Further, the liquid ejecting apparatus 100 is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “applicable liquid” means that the liquid can be attached at least temporarily and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, examination cells, and other media. Unless otherwise specified, everything to which liquid adheres is included.

  The material of the above-mentioned “adherable liquid” may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc., as long as the liquid can be adhered even temporarily.

  The “liquid” is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head. However, the “liquid” has a viscosity of 30 mPa · s or less at room temperature, normal pressure, or by heating and cooling. Preferably there is. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, solutions, suspensions, emulsions, etc., which include, for example, inkjet inks, surface treatment liquids, components of electronic elements and light emitting elements, and formation of electronic circuit resist patterns It can be used in applications such as a liquid for use, a material liquid for three-dimensional modeling.

  In addition, the liquid ejection apparatus 100 includes an apparatus in which the liquid ejection head and the apparatus to which the liquid can adhere move relatively, but the present invention is not limited to this. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

  In addition, the liquid ejecting apparatus 100 includes a processing liquid applying apparatus that discharges a processing liquid onto a sheet in order to apply the processing liquid to the surface of the sheet for the purpose of modifying the surface of the sheet, and the raw materials in the solution. There is an injection granulator for spraying the composition liquid dispersed in the above through a nozzle to granulate fine particles of raw materials.

DESCRIPTION OF SYMBOLS 100 Liquid discharge apparatus 114 Environmental sensor 115 Component detection part 119a Media heater 119b Infrared heater 121 Liquid discharge head 125 Filter 150 Drying part

JP 2017-128039 A Japanese Patent No. 5772382

Claims (9)

A first heating unit for heating the medium in contact with or in proximity to the medium;
A second heating unit for heating the liquid application surface formed on the medium in a non-contact manner;
A temperature detector for detecting the temperature of the medium;
A drying apparatus comprising: a first heating control unit that performs control to lower a heating temperature by the first heating unit when the detected temperature of the medium is equal to or higher than a first temperature. The temperature detection unit detects the temperature of the liquid application surface,
When the detected temperature of the liquid application surface is equal to or higher than a second temperature that is higher than the first temperature, the second heating control unit performs control to lower the heating temperature by the second heating unit. The drying apparatus according to claim 1. The drying apparatus according to claim 1, wherein the second heating unit heats the liquid application surface by infrared radiation. The second heating unit is disposed between the second heating unit and the medium, blocks a resonance wavelength between the infrared ray and the medium radiated by the second heating unit, and is radiated by the second heating unit. The drying apparatus according to claim 3, further comprising a filter that transmits a resonance wavelength between infrared rays and the liquid application surface. The second heating unit and the filter are arranged at a plurality of locations,
The plurality of filters cut off at least one of the resonance wavelengths of the infrared ray and the medium radiated by the second heating unit, and the infrared ray and the liquid application surface radiated by the second heating unit. The drying apparatus according to claim 4, wherein at least one of the resonance wavelengths is transmitted. The first heating control unit includes a resonance wavelength between the infrared ray radiated by the second heating unit and the medium, and a resonance between the infrared ray radiated by the second heating unit and the liquid application surface. The drying apparatus according to any one of claims 3 to 5, wherein when the wavelength is within a predetermined range, control is performed to lower a heating temperature by the first heating unit. The second heating control unit includes a resonance wavelength between the infrared ray radiated by the second heating unit and the medium, and a resonance between the infrared ray radiated by the second heating unit and the liquid application surface. The drying apparatus according to any one of claims 3 to 6, wherein when the wavelength is within a predetermined range, control is performed to reduce a heating temperature by the second heating unit. The second heating control unit performs control to increase the heating temperature by the second heating unit when the absorbance of the liquid application surface and the absorbance of the liquid application surface in a dry state are not within a predetermined range. The drying apparatus according to any one of claims 3 to 7, wherein A liquid discharge head that discharges liquid onto a medium to form a liquid application surface;
A first heating unit that heats the medium in contact with or in proximity to the medium;
A second heating unit for heating the liquid application surface in a non-contact manner;
A temperature detector for detecting the temperature of the medium;
A liquid ejection apparatus comprising: a first heating control unit that performs control to lower a heating temperature by the first heating unit when the detected temperature of the medium is equal to or higher than a first temperature.

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