JP2007086054A - Noncontact method and noncontact apparatus for detecting dew formation, paper deformation control method using them, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform noncontact detection on gas condensation to the surface of an object and transpiration, and to more accurately predict dew formation on the surface of the object, by speedily detecting the process of dew formation on the surface of the object. <P>SOLUTION: Temperature and humidity sensors 4a and 4b, for measuring the temperature and humidity of a gas in ambient atmosphere, are arranged at intermediate locations at a distance from the vicinity of the surface of the object 1, and a temperature and humidity sensors 4c is arranged separated by a distance from the surface of the object 1. A flow sensor is provided for measuring the flow direction or the flow velocity of the gas in the ambient atmosphere of the surface of the object. The state of distribution and transportation process of the ambient atmosphere to the surface of the object 1 are determined, on the basis of the measurement results of the temperature and humidity sensors 4a-4c and the flow sensor 5 for detecting the behavior of the adsorption and condensation of the gas of the ambient atmosphere on the surface of the object 1 and the behavior of transpiration of the liquid which has condensed on the surface of the object. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  This invention has a large heat capacity and cannot be adapted to rapid changes in the temperature and humidity of the surrounding environment, causing condensation on the surface and impairing the function. A non-contact dew condensation detection method, a non-contact dew condensation detection device, a sheet deformation suppression method using the same, and an image forming apparatus capable of performing general-purpose and simple detection of the dew generation state and controlling the humidity of the atmosphere. It is intended to provide.

  Devices made of a material with a large specific heat or a large mass have a large heat capacity and cannot adapt to a rapid change in the temperature and humidity of the surrounding environment, causing condensation on the surface and hindering the function of the device. For example, optical devices such as VTR head cylinders, magnetic and optical recording media such as hard disks and optical disks, lenses, light emitting elements, reflecting mirrors, prisms, filters, optical devices using these, image forming devices such as photosensitive drums and polygons In addition, the window glass of vehicles and aircraft has a great influence on the function of the device due to the occurrence of condensation.

  In addition, since water and gas adsorbed on recording paper such as electrophotographic image forming devices have a large effect on the image quality, the behavior of adsorbed water on the surface of the material is accurately detected by detecting its relationship with the atmosphere. It needs to be controllable. That is, when the moisture contained in the recording paper is dehydrated and dried due to environmental changes, or when the moisture contained in the recording paper is rapidly evaporated and dried by heating of the fixing device or the like, the recording paper shrinks and curls and wrinkles are generated. appear. Since the deformation of the recording paper leads to a conveyance failure in the recording paper conveyance process, it is necessary to prevent the deformation from occurring. In addition, it is also necessary to investigate the relationship with the metabolic state of the living body by detecting the adsorption water phenomenon and the transpiration phenomenon on the living body surface in the animal and plant and medical fields.

Furthermore, in the porous waterproof and moisture permeable membrane shown in Japanese Patent Application Laid-Open No. 2002-310876, which allows water vapor to permeate from one side by a hole and prevents water from entering from the other side, the membrane surface on one side If dew condensation water is formed on the surface, the permeation holes are blocked and the water vapor transmission rate is lowered, so it is necessary to detect the state of dew condensation.
Further, in the power generation unit in which the electrode catalyst layer and the solid electrolyte material film are combined as disclosed in Japanese Patent Laid-Open No. 2002-369885, the condensed water is formed in a liquid form on the solid electrolyte material film. However, in the state of high water retention just before, the transport of gas is ensured and the reaction efficiency of hydrogen and air can be increased. For this reason, it is necessary to detect the water retention rate of the membrane of the solid electrolyte material.
Further, in order to optimally control cooling and dehumidification in a cooling device or the like disclosed in WO 00/14522, it is necessary to detect the state of condensation on the surface of the material to be frozen in the vicinity of the surface of the cooling side heat exchanger.
In addition, in the distillation separation of organic solvents disclosed in Japanese Patent Application Laid-Open No. 2004-083385, etc., in order to precisely control the aggregation / transpiration temperature, the aggregation / transpiration temperature is more than that detected from the temperature of the heat exchanger. The behavior of the surrounding gas can be accurately detected by direct observation.
Thus, in various fields, it is desired to detect the agglomeration and transpiration behavior quickly and with high sensitivity, and to detect the difference in adsorption of gas vapor molecules on various surfaces to detect the hydrophilicity / hydrophobicity of the surface. Has been.

  In order to detect the occurrence of condensation in this way, for example, the condensation detection device disclosed in Patent Document 1 is a VTR rotary cylinder device that has a large heat capacity and is likely to cause condensation. To prevent entanglement, measure the surface temperature of the rotating cylinder and the ambient temperature and ambient humidity in the vicinity of the rotating cylinder, and refer to the moisture content data in air (air diagram) for each humidity temperature. It is determined whether or not it is moving.

  The dew point or gas concentration measurement method and the icing prediction device disclosed in Patent Document 2 have a dew condensation response than the specular cooling method in the measurement method for detecting dew condensation from the dew point obtained from the relative humidity of the atmosphere and the temperature of the measurement target. A relative humidity sensor based on a fast dielectric polymer is used. When using a capacitive polymer capacitive relative humidity sensor that responds quickly, the relative humidity sensor is externally cooled when the relative humidity is low, and high when the relative humidity is near the dew point. Since it is easy to maintain moisture in a humid environment and it is difficult to predict icing, the temperature of the relative humidity sensor is shifted to increase accuracy by externally heating the relative humidity sensor.

  In the dew condensation prediction device disclosed in Patent Document 3, when a thermoelectric element is thermally coupled to the dew condensation sensor and the dew condensation sensor is predicted to be lower than the ambient temperature by the thermoelectric element, water droplets are long on the dew condensation sensor. When the material stays for a long time, the material deteriorates, so the condensation sensor is heated by a thermoelectric element to remove the condensed water generated in the condensation sensor.

  In addition, the phase change prediction sensor and the frost / condensation prevention device disclosed in Patent Document 4 are equipped with a dew condensation sensor via a Peltier element on the test object, and the test target is not allowed to enter and exit the detection system. The temperature of the dew condensation sensor is always lower by a certain value than the dew condensation surface, which is an object, so that dew condensation is performed in advance and the occurrence of dew condensation or frost formation is predicted in advance.

  The vehicle humidity sensor disclosed in Patent Document 5 is a heat coupling member in which a housing of a sensor main body that detects the temperature of each area in a passenger compartment and a windshield of a vehicle are formed in a cup shape by a heat conductive material. The infrared rays incident from each area are detected by the sensor element, and when the temperature distribution in each area falls within a predetermined range, it is determined that the wind seal is condensed.

  Further, there is a non-contact temperature measuring device disclosed in Patent Document 6 that utilizes the fact that the heat flow between the reference object and the external object is proportional to the temperature of the external object. This non-contact temperature measuring device calculates the temperature of a moving object by detecting the temperature of a first reference object and a second reference object provided at a predetermined distance along a moving continuous object by a temperature sensor. Like to do.

Also, in order to avoid the occurrence of curling and wrinkling on the recording paper of the electrophotographic image forming apparatus and the occurrence of transport trouble in the transporting process of the recording paper, as shown in Patent Document 7, an infrared moisture meter is used. The amount of water contained in each part of the recording paper is detected, and the amount of air applied to each part of the recording paper is adjusted based on the detected amount of water to prevent partial curl due to non-uniformity of the water content. Also, as shown in Patent Document 8, the amount of water contained in the recording paper is detected from the change in transmittance of the infrared light reflected from the recording paper, and the fixing temperature of the fixing device and the paper conveyance path are detected based on the detected amount of water. The roller pressure is controlled. Also, as shown in Patent Document 9, a moisture meter that measures the absorption rate of microwaves detects the amount of moisture contained in a recording sheet, and the detected amount of moisture and the type of recording sheet, that is, the strength of the recording sheet (high stiffness) The curl state of the recording paper is predicted from the above and the like, and the curl is corrected according to the predicted curl state.
Japanese Patent Laid-Open No. 3-78648 Japanese Patent No. 2801156 Japanese Patent Laid-Open No. 1-127942 JP-A-4-1288643 JP 2004-66927 A Japanese Patent No. 3292523 JP 2005-170525 A JP 2001-301273 A Japanese Patent No. 2902130

  In the dew condensation detection device disclosed in Patent Document 1, it is necessary to attach a dew condensation sensor to the rotating cylinder in accordance with the dew generation characteristic in the rotating cylinder of the VTR rotating cylinder device, and a general-purpose sensor that simply attaches the dew condensation sensor. In addition, it is not possible to detect dew condensation with this method, and there are restrictions on the function of the magnetic head and the reception of electrical signals to the rotating body when the dew condensation sensor is attached to the rotating cylinder.

  In addition, in the case where dew condensation is detected by the method shown in Patent Literature 2 and the devices shown in Patent Literature 3 and Patent Literature 4 externally heat the sensor temperature or lower than the ambient temperature, The atmosphere measured by the sensor is in a temperature state different from the atmosphere to be condensed, and the humidity of the atmosphere having a temperature different from the atmosphere to be condensed is detected, so that the detection accuracy is deteriorated.

  The dew condensation estimation method disclosed in Patent Document 5 requires a sensor to be attached to the dew condensation surface, which is a measurement target, and is disadvantageous in that it is not versatile. The non-contact temperature measuring device disclosed in Patent Document 6 can measure the temperature of a remote object in a non-contact manner by measuring the temperature gradient of the gas, but is not a method for measuring a gas-liquid phase change such as condensation.

  In any case, when measuring the dew condensation on the object surface, the dew condensation sensor detects the occurrence of dew condensation on the dew condensation sensor itself, and cannot detect the occurrence of dew condensation on the object itself.

  In addition, the dew condensation sensor requires special devices in the thermal structure according to the characteristics of the dew generation of the object, and it is a general-purpose sensor that can be easily attached to the object or placed near it. It is not possible to detect the occurrence of condensation on the target object.

  In addition, even if there is a condensation prediction function, it works as a system using a condensation prediction algorithm that is set by detecting the temperature at a specific location in the device, so it can be used universally only for application to a specific device. It is not a condensation prediction method.

  In addition, when measuring condensation away from the object to be measured, when using optical means such as a mirror-cooled dew point meter, the measurement surface state is limited to the mirror surface, and it is universal for any surface. It cannot be used for. In addition, a method of detecting the dew condensation phenomenon using a combination of a humidity sensor that detects the atmospheric state and an infrared radiation thermometer that measures the object temperature can be considered, but since the emissivity varies depending on the surface state, the temperature cannot be obtained accurately and is known. Only the portion of the surface temperature of the emissivity can be measured, and it is not certain whether the humidity of the surface of the object to be measured is detected.

  Further, in the image forming apparatus, deformation such as curling that occurs on the recording paper is caused by abrupt drying of the recording paper, and the drying speed is a direct cause. The drying speed of the recording paper is governed by the transpiration rate in the transpiration behavior of moisture contained in the recording paper. This transpiration behavior reflects the quality and structure of the recording paper and the strength of the quality and structure. Therefore, as shown in Patent Document 7 to Patent Document 9, it is difficult to predict with high accuracy deformation such as curl occurring on the recording paper even if the amount of moisture contained in the recording paper is detected.

  The present invention improves these disadvantages, and does not attach a dew condensation sensor directly to the measurement object, but also causes agglomeration of gas from the physical state change of the ambient atmosphere, which is a continuous space in contact with the measurement object, to the surface of the measurement object. Transpiration can be detected at a remote location without contact with the surface of the object, and the process of forming condensation on the surface of the measurement object can be quickly detected to more accurately predict the condensation on the surface of the measurement object. It is an object of the present invention to provide a non-contact dew condensation detection method and a non-contact dew condensation detection device.

  In addition, the non-contact dew condensation detection device of the present invention is used to detect the evaporation rate of moisture contained in the recording paper for forming an image in real time and to prevent deformation such as curling of the recording paper caused by rapid drying. An object of the present invention is to provide a sheet deformation suppressing method and an image forming apparatus capable of predicting with high accuracy and preventing deformation of a recording sheet.

  The non-contact dew condensation detection method according to the present invention is a distribution state of the ambient atmosphere with respect to the object surface by combining any one or each element of the temperature, humidity, flow direction, flow velocity, pressure, and component of the atmosphere in the ambient atmosphere of the object surface. And the behavior of the ambient atmosphere on the object surface and the behavior of the ambient atmosphere adsorbing and agglomerating on the object surface and the behavior of the agglomerated liquid evaporating on the object surface. It is characterized by detecting.

  Each element of the gas in the ambient atmosphere is measured at least at two locations near the object surface and at a distance from the object surface.

  In addition, a wall having a frictional resistance against the ambient atmosphere gas should be placed close to the object surface and in a direction in which the ambient atmosphere gas flows at the location where each element of the ambient atmosphere gas is measured. Is desirable.

  Further, the measurement points for measuring each element of the gas in the ambient atmosphere are measured in the direction in which the transport components of the gas along the gravity are opposite to each other, and are measured in the directions in which the transport components of the gas along the gravity are in conflict. It is preferable to detect the behavior in which the gas in the ambient atmosphere adsorbs and aggregates on the object surface and the behavior in which the liquid aggregated on the object surface evaporates.

  Further, at the place where each element of the gas in the ambient atmosphere is measured, a wall surface having a frictional resistance against the gas in the ambient atmosphere is arranged close to the object surface and in a direction in which the gas in the ambient atmosphere flows, Each element of the gas in the ambient atmosphere may be measured at at least two locations in the vicinity of the wall surface and remote from the object surface.

  Furthermore, it is desirable that the wall surface is formed of a rectifying tube formed in a cylindrical shape and measured in a rectifying space. It is preferable to reduce the inner diameter of a part of the rectifying pipe to increase the flow velocity of the rectifying space.

  The non-contact dew condensation detection apparatus according to the present invention includes a measurement unit and a processing unit, and the measurement unit is disposed at least at two locations in the vicinity of the object surface and remote from the object surface. A temperature / humidity sensor that measures the temperature and humidity of the gas, and a flow sensor that measures the flow direction or flow velocity of the gas in the ambient atmosphere around the object surface, and the processing device is a measurement result of the temperature / humidity sensor and the flow sensor. It is characterized by detecting the distribution state and transport process of the ambient atmosphere on the object surface and detecting the behavior of the ambient atmosphere gas adsorbing and agglomerating on the object surface and the behavior of the agglomerated liquid evaporating on the object surface. To do.

  The measuring means may be provided in a rectifying tube arranged close to the object surface.

  Another non-contact dew condensation detection apparatus of the present invention includes a measuring unit and a processing unit, and the measuring unit includes a rectifying pipe disposed close to the object surface, a vicinity of the wall surface of the rectifying pipe, and a wall surface. A temperature / humidity sensor which is disposed at two locations away from the object and which measures the temperature and humidity of the gas in the ambient atmosphere around the object surface; and a flow sensor which measures the flow direction or flow velocity of the gas in the rectifying pipe, The processing device determines the distribution state of the ambient atmosphere on the object surface and the transport process based on the measurement results of the temperature and humidity sensor and the flow sensor, and the behavior of the ambient atmosphere gas adsorbing and aggregating on the object surface and on the object surface. It is characterized by detecting the behavior of agglomerated liquid evaporating.

  The measuring means may include a sensor for measuring the pressure and components of the gas in the ambient atmosphere around the object surface.

  The paper deformation suppression method of the present invention is a transpiration rate which is a transpiration rate per unit time from a measured evaporation amount by measuring the transpiration amount of a volatile component contained in various papers by the non-contact dew condensation detection method described above. And the drying condition of the paper is set so that the calculated transpiration rate does not exceed the preset reference value of the transpiration rate until a predetermined time until the paper is deformed.

  When transporting the paper, it is desirable to measure the transpiration amount of the volatile component contained in the front end of the paper at a plurality of locations along the paper transport path.

  An image forming apparatus according to the present invention includes the non-contact dew condensation detection device according to any one of the above, and measures a transpiration amount of moisture contained in the recording sheet while conveying the recording sheet on which an image is formed, and measures the evaporation amount The transpiration rate, which is the amount of transpiration per unit time, is calculated from the recording paper so that the calculated transpiration rate does not exceed a preset reference value of the transpiration rate until a predetermined time until the recording paper is deformed. The drying conditions are set.

  In the image forming apparatus, it is desirable to measure the transpiration amount of moisture contained in the leading end portion of the recording paper at a plurality of locations along the recording paper conveyance path.

  A second image forming apparatus according to the present invention includes a plurality of measurement units and a deformation prediction control unit of the non-contact dew condensation detection device according to any one of the above, and the plurality of measurement units are arranged on a recording paper conveyance path. The deformation prediction control device includes a transpiration behavior calculation processing unit, a deformation prediction processing unit, and a deformation avoidance control unit, and the transpiration behavior calculation processing unit is a measurement output from the plurality of measurement means. Detecting the transpiration behavior of moisture contained in the leading edge of the recording paper based on the signal, calculating the transpiration amount, calculating the transpiration rate per unit time from the calculated transpiration amount, and the deformation prediction processing The transpiration rate calculated by the transpiration behavior calculation processing unit is compared with the reference value of the transpiration rate until a predetermined time until the recording paper is deformed, and the calculated transpiration rate exceeds the reference value. When carrying It is determined that deformation occurs in the recording sheet that has been generated, and deformation prediction information is generated, and the deformation avoidance control unit generates either the recording sheet conveyance speed or the fixing temperature based on the deformation prediction information generated by the deformation prediction processing unit. One or both are variably controlled.

  A third image forming apparatus of the present invention includes a plurality of measurement units and a CPU of the non-contact dew condensation detection device according to any one of the above, and the plurality of measurement units include a plurality of measurement units along a conveyance path of a recording sheet. The CPU is arranged at a location, and the CPU detects the transpiration behavior of moisture contained in the front end portion of the recording paper based on the measurement signals output from the plurality of measuring means, calculates the transpiration amount, and calculates the transpiration amount from the calculated transpiration amount. Calculate the transpiration rate, which is the amount of transpiration per unit time, and compare the calculated transpiration rate with the preset reference value of the transpiration rate until a certain time until the recording paper is deformed. When the value exceeds a reference value, it is determined that the recording paper being conveyed is deformed, and either or both of the recording paper conveyance speed and the fixing temperature are variably controlled.

  It is preferable that the measuring unit has a position sensor for detecting the leading edge of the recording paper.

  The present invention improves versatility by measuring the distribution and transport process of the surrounding atmosphere affected by the behavior of the object surface and detecting the behavior of condensation and transpiration on the object surface without contact. be able to.

  By measuring each element of the gas in the ambient atmosphere at least two locations near the object surface and remote from the object surface, it is possible to accurately measure the distribution state and transport process of the ambient atmosphere to the object surface, It is possible to accurately detect the behavior of condensation and transpiration on the surface of an object in real time.

  Furthermore, by providing a wall or rectifying space that has a frictional resistance against the gas in the ambient atmosphere at the location where each element of the gas in the ambient atmosphere is measured, the distance of the measurement location along the transport direction of the ambient atmosphere can be shortened. At the same time, it is possible to measure an atmosphere with little fluctuation from the outside in the vicinity of the object surface, and to accurately measure the distribution state of the surrounding atmosphere with respect to the object surface and the transport process.

  In addition, by measuring the location where each element of gas in the ambient atmosphere is measured in the opposite direction of the transport component of the gas along gravity, the influence of fluctuations from the outside world can be eliminated, and the surroundings can be removed. The distribution state of the atmosphere with respect to the object surface and the transport process can be accurately measured.

  In addition, the process of forming condensation on the object surface can be detected without contact with the object surface without attaching a condensation sensor directly to the object, preventing condensation by more accurately predicting condensation and transpiration on the object surface. Etc. can be controlled efficiently.

  In addition, the transpiration rate of volatile components contained in various papers is measured, the transpiration rate is calculated from the measured evaporation rate, and the calculated transpiration rate is a standard for the transpiration rate up to a certain time until the preset paper is deformed. By setting the drying condition of the sheet so as not to exceed the value, it is possible to prevent the sheet from being deformed due to evaporation of moisture contained in the sheet.

  In addition, the amount of moisture contained in the recording sheet is measured while the recording sheet on which the image is formed is measured, the evaporation rate is calculated from the measured evaporation amount, and the calculated evaporation rate is deformed in the preset recording sheet. By setting the drying condition of the recording paper so as not to exceed the reference value of the transpiration rate up to a certain period of time, the recording paper can be stably conveyed while preventing deformation of the recording paper.

  Furthermore, by measuring the amount of transpiration of the moisture contained in the leading edge of the recording paper at a plurality of locations along the recording paper conveyance path, the dry state is detected by the transpiration of the portion that greatly affects the deformation of the recording paper. Thus, deformation of the recording paper can be reliably suppressed.

  Also, by measuring the amount of transpiration of moisture contained in the leading edge of the recording paper at multiple locations along the recording paper conveyance path, the transpiration behavior can be measured at the same location on the recording paper to obtain an accurate transpiration rate. Can do.

  Furthermore, by providing a position sensor for detecting the leading edge of the recording paper in the measuring means for measuring the transpiration behavior of the recording paper, the amount of transpiration of moisture contained in the leading edge of the recording paper can be reliably measured. The transpiration rate can be obtained.

  First, the state change of the ambient atmosphere of the object will be described when the gas in the ambient atmosphere is adsorbed on the surface of the object and aggregates and condenses, and the aggregated liquid evaporates. When the gas in the ambient atmosphere 2 is adsorbed and aggregated on the surface of the object 1, the gas in the atmosphere 2 remote from the surface of the object 1 flows in the direction near the surface of the object 1 and is adsorbed on the surface of the object 1 as shown in FIG. When the gas is desorbed or when the liquid condensed on the surface of the object 1 evaporates, the atmosphere 2 near the surface of the object 1 flows from the surface of the object 1 in the remote direction.

  The ambient atmosphere 2 accompanying the adsorption / aggregation on the surface of the object 1 has a temperature distribution and a density distribution along the transport direction. FIGS. 2A and 2B show the temperature distribution and the relative humidity distribution of the ambient atmosphere 2 that change according to the distance from the surface of the object 1 to the surface temperature of the object 1. 2 (a) and 2 (b) show that the ambient ambient temperature 2 at the remote location is T1 and the surface temperature of the object 1 is T1, T2, T3, T4, where T1> T2> T3> T4 and the atmospheric dew point. The temperature Td indicates a case where the temperature is between the temperature T2 and the temperature T3. 2A shows the temperature on the horizontal axis, the distance from the surface of the object 1 on the vertical axis, FIG. 2B shows the relative humidity on the horizontal axis, and the vertical axis of the object 1. Indicates the distance from the surface.

When the temperature of the object 1 is the same as the temperature T1 of the ambient atmosphere 2, the relative humidity of the ambient atmosphere 2 is uniformly distributed everywhere. Further, when the temperature of the surface of the object 1 is relatively low with respect to the temperature T1 of the ambient atmosphere 2, the air and water vapor gas molecules interact with the surface of the object 1 in the vicinity of the object 1 surface. Due to the action, the temperature of the ambient atmosphere 2 near the surface of the object 1 is lowered. Thus, when the temperature of the ambient atmosphere 2 near the surface of the object 1 is decreased, the saturated water vapor pressure is decreased, and therefore the relative humidity indicated by the water vapor pressure // saturated water vapor pressure is increased.
In the vicinity of the object surface, the relative humidity is higher than in the remote area. At this stage, the amount of water vapor molecules adsorbed on the surface of the object 1 is increased, but since there is still an amount of desorption from the surface of the object 1, dew condensation that forms water molecules on the surface of the object 1 has not been achieved.

  When the temperature of the surface of the object 1 is further lowered with respect to the temperature T1 of the ambient atmosphere and becomes a temperature T3 lower than the atmospheric dew point temperature Td, the amount of water vapor molecules adsorbed on the surface of the object 1 is larger than the amount desorbed from the surface of the object 1. Thus, on the surface of the object 1, water vapor molecules form a cluster of water molecules, resulting in dew condensation. Even if the transport of water vapor molecules from a remote location to the surface of the object 1 from the surface of the object 1 increases, depending on the temperature of the ambient atmosphere 2 in the vicinity of the surface of the object 1, 1 mol of 22400 cc of water vapor near the surface of the object 1 Since it aggregates into 18 cc of water, it becomes 1/1244, and water vapor molecules are deficient in the vicinity of the surface of the object 1. Therefore, although the surface of the object 1 is lowered to the temperature T3, the ambient atmosphere 2 in the vicinity of the surface of the object 1 has a lower relative humidity than the remote. In addition, as shown in FIG. 2, the ambient atmosphere 2 near the surface of the object 1 and the remote intermediate atmosphere 2 has a high relative humidity because the temperature decreases. When the temperature of the surface of the object 1 is further lowered to the temperature T4 with respect to the temperature T1 of the ambient atmosphere, dew condensation proceeds, and the ambient atmosphere 2 near the surface of the object 1 is further compared with the case of the object 1 surface temperature T3. Has a lower relative humidity than remote.

  Condensation proceeds as long as the surface temperature of the object 1 is equal to or lower than the dew point Td. However, when the surface temperature of the object 1 exceeds the dew point Td, it evaporates and transports water vapor molecules from the surface of the object 1 to a remote location. In this manner, the adsorption / aggregation process / equilibrium / transpiration process of the ambient atmosphere 2 on the surface of the object 1 is separated from the surface of the object 1 by measuring changes in the temperature gradient, humidity gradient, and flow state of the ambient atmosphere 2. It is possible to realize remote detection of the dew condensation behavior and the transpiration behavior of the surface of the object 1 in a non-contact manner.

  The block diagram of FIG. 3 shows the configuration of the non-contact dew condensation detection device 3 that remotely detects the behavior of dew condensation and transpiration on the surface of the object 1 without contact. As shown in FIG. 3, the non-contact dew condensation detection device 3 includes a plurality of temperature / humidity sensors 4 a, 4 b, 4 c, a flow sensor 5, and a processing device 6. As shown in FIG. 4, the temperature / humidity sensor 4a is disposed near the surface of the object 1 at a distance h from the surface, detects the temperature Ta and the humidity Ha of the ambient atmosphere 2 near the surface of the object 1, The humidity sensor 4b is disposed at an intermediate position in the vicinity of the surface of the object 1, and detects the temperature Tb and the humidity Hb of the ambient atmosphere 2 at the intermediate position. The temperature / humidity sensor 4c is disposed at a position remote from the surface of the object 1. The temperature Tc and humidity Hc of the ambient atmosphere 2 remote from the surface of the object 1 are detected. The flow sensor 5 is arranged in the middle of the object 1 near the surface and remotely, and detects the flow direction Fz and the flow velocity Wa of the ambient atmosphere 2. The processing device 6 includes an operation unit 7, an arithmetic processing unit 8, a storage unit 9, and an alarm output unit 10. The arithmetic processing unit 8 inputs the temperature of the ambient atmosphere 2 detected by the temperature / humidity sensors 4a to 4c and the flow sensor 5 and the flow direction and flow velocity of the ambient atmosphere 2 every predetermined time set in advance. The humidity and the transport direction are stored in the storage unit 9, and the behavior of dew condensation and transpiration on the surface of the object 1 is determined from changes in the input temperature, humidity, and flow direction. When the dew condensation signal or transpiration signal is output from the arithmetic processing unit 8, the alarm output unit 10 outputs the dew condensation alarm signal or transpiration signal to the temperature and humidity control device.

  Processing when the non-contact dew condensation detection device 3 detects the occurrence of dew condensation on the surface of the object 1 will be described with reference to the flowchart of FIG. 5 and FIGS. 4 (a) and 4 (b).

  The arithmetic processing unit 8 of the processing device 6 includes the temperature T and humidity H of the ambient atmosphere 2 and the flow direction Fz of the ambient atmosphere 2 detected by the temperature / humidity sensors 4a to 4c and the flow sensor 5 at predetermined time intervals. And the inputted temperature H, humidity H, and transport direction Fz are stored in the storage unit 9 (step S1). In this state, when the time t (n) reaches the time t (n + 1) (step S2), the arithmetic processing unit 8 detects the neighborhood temperature Ta (n + 1) and the temperature / humidity sensor input from the temperature / humidity sensor 4a at the time t (n + 1). The remote temperature Tc (n + 1) input from 4c, the near humidity Ha (n + 1) input from the temperature / humidity sensor 4a and the remote humidity Hc (n + 1) input from the temperature / humidity sensor 4c are compared (step S3). When the n + 1) and the remote temperature Tc (n + 1) are the same, the surface temperature T1 of the object 1 and the remote temperature Tc (n + 1) are the same as shown in FIG. It is determined that the amount of adsorbed water vapor molecules is small (step S7). Further, the near temperature Ta (n + 1) input by the temperature / humidity sensor 4a is lower than the remote temperature Tc (n + 1) input by the temperature / humidity sensor 4c, and the near humidity Ha (n + 1) input by the temperature / humidity sensor 4a is the temperature / humidity sensor 4c. If it is higher than the remote humidity Hc (n + 1) input in step 1, it is determined that there is a possibility of adsorbing water vapor molecules in the surrounding atmosphere 2 on the surface of the object 1, and time t (n) and time t ( n + 1) is compared with the humidity input by the temperature / humidity sensor 4a and the temperature / humidity sensor 4c (step S4), and the neighboring humidity Ha (n + 1) input from the temperature / humidity sensor 4a at time t (n + 1) is determined at time t (n). The remote humidity Hc (n + 1) input at the time t (n + 1) from the temperature / humidity sensor 4c, which is smaller than the input nearby humidity Ha (n), is input at the time t (n). When the flow direction Fz of the surrounding atmosphere 2 input from the flow sensor 5 at time t (n + 1) is larger than (n) and is on the surface side of the object 1 as shown in FIG. It is determined that the amount of adsorbed water vapor molecules in the ambient atmosphere 2 is greatly agglomerated, and the arithmetic processing unit 8 outputs a dew condensation signal indicating that dew condensation may occur on the surface of the object 1 to the alarm output unit 10 (step S5). ). When the dew condensation signal is sent from the arithmetic processing unit 8, the alarm output unit 10 outputs the dew condensation alarm signal to a temperature / humidity control device such as a dehumidifying device (step S6). Further, as a result of comparing the humidity input by the temperature / humidity sensor 4a and the temperature / humidity sensor 4c at the time t (n) and the time t (n + 1), which are a predetermined time before (step S4), the vicinity input at the time t (n + 1) The remote humidity Hc (n + 1) input at time t (n) is the same as or greater than the neighboring humidity Ha (n) input at time t (n) and the remote humidity Hc (n + 1) input at time t (n + 1). If the flow direction Fz of the ambient atmosphere 2 input from the flow sensor 5 at time t (n + 1) is not the surface side of the object 1 at the time t (n + 1), the amount of water vapor molecules adsorbed in the ambient atmosphere 2 on the surface of the object 1 (Step S7). This process is repeated while the measurement is continued (steps S8 and S2).

  Next, processing when the non-contact dew condensation detection device 3 detects the occurrence of transpiration from the surface of the object 1 will be described with reference to the flowchart of FIG. 6 and FIG.

  The arithmetic processing unit 8 inputs the temperature T and humidity H of the ambient atmosphere 2 and the flow direction Fz of the ambient atmosphere 2 detected by the temperature / humidity sensors 4a to 4c and the flow sensor 5 at predetermined time intervals, The input temperature H, humidity H, and transport direction Fz are stored in the storage unit 9 (step S11). When the time t (n) reaches the time t (n + 1) in this state (step S12), the arithmetic processing unit 8 uses the neighborhood humidity Ha (n + 1) and the temperature / humidity sensor input from the temperature / humidity sensor 4a at the time t (n + 1). The remote humidity Hc (n + 1) input from 4c is compared (step S13). If the near humidity Ha (n + 1) is smaller than the remote humidity Hc (n + 1), it is determined that there is no transpiration from the surface of the object 1 (step S17). Further, when the near humidity Ha (n + 1) is larger than the remote humidity Hc (n + 1), it is determined that there is a possibility that water vapor molecules are evaporated from the surface of the object 1, and the time t (n) and the time t (n + 1) are determined. At this time, the flow direction Fz of the ambient atmosphere 2 input from the flow sensor 5 is changed, and it is determined whether or not the flow direction Fz of the ambient atmosphere 2 at the time t (n + 1) is opposite to the surface of the object 1. (Step S14) When the flow direction Fz of the ambient atmosphere 2 at time t (n + 1) is opposite to the surface of the object 1 as shown in FIG. It is determined that the molecules are transpiration (step S15), and a transpiration signal indicating that water vapor molecules are transpiration from the surface of the object 1 is output to the alarm output unit 10. When the transpiration signal is sent from the arithmetic processing unit 8, the alarm output unit 10 outputs the transpiration alarm signal to a temperature / humidity control device such as a dehumidifying device (step S16). If the flow direction Fz of the ambient atmosphere 2 at time t (n + 1) is not opposite to the surface of the object 1, it is determined that there is no transpiration from the surface of the object 1 (step S17). This process is repeated while the measurement is continued (steps S18 and S12).

  By measuring the temperature gradient and humidity gradient of the ambient atmosphere 2 with respect to the surface of the object 1 and changes in the flow state in this way, it is possible to detect the dew condensation behavior and the transpiration behavior of the surface of the object 1 at a location away from the surface of the object 1. it can.

  In the above description, the case where the temperature / humidity sensors 4a to 4c and the flow sensor 5 are arranged in the direction perpendicular to the surface of the object 1 is described, but as shown in FIG. The wall surface 11 is provided perpendicular to the surface of the object 1, and the temperature / humidity sensors 4 a, 4 b and the flow sensor 5 are disposed at a position separated from the surface of the object 1 by a distance h 1 corresponding to the middle of the wall surface 11. The sensor 5 may be disposed at a position away from the wall surface 11, and the temperature / humidity sensor 4 b may be disposed near the wall surface 11. When the temperature / humidity sensors 4a to 4c and the flow sensor 5 are arranged in the direction perpendicular to the surface of the object 1, the temperature / humidity sensor 4a in the vicinity of the surface of the object 1 is affected by the object 1 at an early stage, and the temperature remote from the surface of the object 1 The humidity sensor 4c receives the influence of the object 1 later than the temperature / humidity sensor 4a. Focusing on this behavior, as shown in FIG. 7, the wall surface 11 is arranged, the temperature / humidity sensors 4 a and 4 b and the flow sensor 5 are arranged at the same distance h 1 from the surface of the object 1, and the time affected by the object 1 Make a difference.

When the wall surface 11 serving as the gas transport friction resistance is provided on the surface of the object 1 as described above, the thickness of the boundary layer in which the laminar flow velocity flowing along the wall surface 11 from the upper portion of the wall surface 11 receives the friction resistance of the wall surface 11. δ is δ≈5 * (νx / U) ^1/2 according to Stokes' law, where x is the distance along the wall surface 11 from the upper end of the wall surface 11, U is the flow velocity, and ν is the frictional resistance of the wall surface 11. can get. The thickness of the boundary layer with respect to the distance x along the wall surface 11 from the upper end of the wall surface 11 when the flow velocity U is changed to 1 mm / second, 5 mm / second, 10 mm / second, 100 mm / second, and 1000 mm / second with air at 20 ° C. FIG. 8 shows the change of the depth δ. The flow at a flow velocity U = 5 mm / second moves 0.5 mm after 0.1 second. However, at a distance X = 1 mm from the wall end surface, when the distance away from the wall surface 11 is 9 mm, 10 mm, or 11 mm, the friction of the wall surface 11 As shown by the flow F in the broken-line circle in FIG.

  Therefore, when the temperature / humidity sensor 4a and the flow sensor 5 are arranged at positions away from the wall surface 11 and the temperature / humidity sensor 4b is arranged near the wall surface 11, the atmosphere 2 detected by the temperature / humidity sensor 4a at the certain time t is more wall surface. 7, since the flow precedes and the temperature / humidity sensor 4b is close to the wall surface 11 as shown in FIG. 7, the flow slows down due to frictional resistance, and the arrival time of the influence on the surface of the object 1 This is equivalent to detecting the atmosphere 2 that is slow and away from the surface of the object 1, and is based on the ambient temperatures Ta and Tb detected by the temperature / humidity sensors 4 a and 4 b and the flow direction Fz detected by the flow sensor 5. Condensation behavior on the surface of the object 1 at a location away from the surface of the object 1 by measuring changes in the temperature gradient, humidity gradient, and flow state of the ambient atmosphere 2 It is possible to detect the evaporation behavior.

  In disposing the temperature / humidity sensor 4 along the transportation of the gas accompanying the adsorption / aggregation on the surface of the object 1, it is necessary to lengthen the transportation distance in order to obtain the detection resolution, and the installation structure becomes large. On the other hand, as shown in FIG. 7, a wall surface 11 is provided on the surface of the object 1, and the temperature / humidity sensors 4 a and 4 b and the flow sensor 5 are arranged at a position separated by a distance h 1 corresponding to the middle of the wall surface 11. Thus, the measurement mechanism can be made compact.

  Further, depending on the transport mechanism of the gas, the atmospheric state may change with a gentle gradient depending on the transport speed. In such a case, measurement becomes difficult, but as shown in FIG. On the other hand, a steep gradient can be given to the atmospheric state by providing the wall surface 11 which becomes the gas transport friction resistance.

  Furthermore, when the temperature / humidity sensors 4a and 4b are installed at two locations away from the surface of the object 1, depending on factors such as the temperature gradient, viscosity, density, thermal conductivity, gravity, and vapor pressure of the gas forming the ambient atmosphere 2. Depending on the distance to the surface of the object 1, a density gradient may occur in the minute space. In such a case, the distance from the surface of the object 1 decreases the influence of the surface of the object 1 and increases the influence of fluctuations in the surrounding environment. For this phenomenon, as shown in FIG. 7, a wall surface 11 is provided on the surface of the object 1, and the temperature / humidity sensors 4a and 4b and the flow sensor 5 are arranged at a position separated from the surface of the object 1 by a certain distance h1. If the measurement mechanism is made compact, the influence of fluctuations in the surrounding environment can be reduced.

  The wall surface 11 having frictional resistance, the temperature / humidity sensors 4a and 4b, and the flow sensor 5 have a very small heat capacity or a thermal conductivity of the ambient atmosphere 2 so as not to affect the thermal state of the ambient atmosphere 2. It is desirable to use similar materials.

  FIG. 7 illustrates the case where the temperature / humidity sensors 4a, 4b and the flow sensor 5 are arranged in the middle of the wall surface 11, but the temperature / humidity sensors 4a, 4b and the flow sensor 5 are disposed on the wall surface as shown in FIG. 11 near the surface of the object 1 opposite to the surface of the object 1, or as shown in FIG. 9B, the temperature / humidity sensors 4a, 4b and the flow sensor 5 are disposed near the surface of the object 1 on the wall surface 11. Also good. As shown in FIG. 9A, the temperature / humidity sensors 4a and 4b and the flow sensor 5 are arranged in the vicinity of the end of the wall 11 opposite to the surface of the object 1, and the distance x of the wall end surface along the wall 11 is set. The closer to zero, the boundary layer is closer to the wall even if the flow velocity range is wider, so the thickness δ of the boundary layer is reduced to a narrow distance, and the temperature / humidity sensors 4a, 4b and the flow sensor 5 are closer to the wall surface 11. It can be arranged, and the measuring mechanism can be made more compact to measure a wide flow velocity range. Further, as shown in FIG. 9B, the temperature and humidity sensors 4a and 4b and the flow sensor 5 are arranged in the vicinity of the end of the wall 11 opposite to the surface of the object 1, so that the length of the wall 11 can be shortened. The ambient atmosphere 2 flowing in opposite directions due to aggregation and transpiration can be easily measured.

  In addition, the specific gravity of the ambient atmosphere 2 on the surface of the object 1 increases as the temperature decreases, and is less likely to rise due to the influence of gravity and is likely to fall, and the temperature gradient changes accordingly. On the contrary, the specific gravity becomes smaller and lighter as the temperature of the ambient atmosphere 2 on the surface of the object 1 is higher and the humidity is lower. FIG. 10A shows a state in which the distance from the surface of the object 1, the temperature of the atmosphere, and the humidity distribution are different between the upper surface and the lower surface of the object 1 depending on the temperature condition of the surface of the object 1. When the object surface temperature is lower than the ambient atmosphere temperature, the ambient atmosphere 2 above the surface of the object 1 is cooled by the surface of the object 1, the specific gravity increases, and the object is lowered by gravity. The distance affected by heat from one surface is shortened. The ambient atmosphere 2 below the surface of the object 1 is cooled by the surface of the object 1 when the object surface temperature is lower than the ambient temperature. Increases the distance affected by heat. If the transport speed is very small along the gas transport direction accompanying adsorption / aggregation on the surface of the object 1, the influence of fluctuations in the outside world may be greater. When the surface fluctuation, surface condition, specific heat, and capacity of both surfaces of the object 1 are relatively the same and are limited to a dew condensation surface that causes a similar dew condensation phenomenon, as shown in FIG. By obtaining the difference in the dew condensation behavior between the upper surface and the lower surface of the surface, it is possible to eliminate the influence of fluctuations in the outside world.

  Therefore, as shown in FIG. 11A, the temperature / humidity sensors 4a, 4b and the flow sensor 5 are arranged above the object 1, and the temperature / humidity sensors 41a, 41b and the flow sensor 51 are also arranged below the object 1. If the behavior of the gas 1 adsorbed and aggregated on the surface of the object 1 due to the difference in measured values both above and below the object 1 or the behavior of the condensed liquid evaporating is detected, the influence of fluctuations in the external world can be eliminated.

  Further, for example, the flow direction Fz of the surrounding atmosphere can be detected by the flow sensor 5 disposed above the object 1, and therefore, as shown in FIG. 11 (b), the flow sensor only on one surface side of the object 1, for example, the upper side. 5 may be arranged. Furthermore, as shown in FIG. 11 (c), even if the surface of the object 1 is inclined, the influence of fluctuations in the outside world can be removed by using the influence of the transport of the surrounding atmosphere 2 along the direction of gravity. Note that the lower surface of the dew condensation surface, which is the surface of the object 1, has a longer transport distance due to gravity than the upper surface, and the measurement interval is longer, resulting in higher sensitivity. Therefore, even if the transport speed is very small, depending on the degree of fluctuation in the external environment, dew condensation may occur. Condensation behavior can be detected only on the lower surface.

  Further, another measuring means in which the temperature / humidity sensors 4a and 4b and the flow sensor 5 are arranged so as to eliminate disturbance without being influenced by fluctuations in the atmosphere of the outside world will be described. As shown in FIG. 12, this measuring means 12 arranges temperature / humidity sensors 4a and 4b and a flow sensor 5 in a flow path inside a rectifying tube 13 formed in a cylindrical shape, and creates an ambient atmosphere 2 with respect to the surface of the object 1. Isolation from the outside by the rectifier 13 eliminates fluctuations and disturbances in the outside atmosphere. Here, FIG. 12A shows the measuring means 12a in which the temperature / humidity sensors 4a and 4b and the flow sensor 5 are arranged along the wall surface of the rectifying tube 13, and FIG. 12B is orthogonal to the wall surface of the rectifying tube 13. The measurement means 12b which arrange | positioned the temperature / humidity sensors 4a and 4b and the flow sensor 5 is shown. The measuring means 12b shown in FIG. 12 (b) gives a steep gradient to the atmospheric state at the wall surface of the rectifying tube 13 as with the wall surface 11 shown in FIG. Remove the influence and eliminate the disturbance. The rectifying tube 13 is also preferably formed of a material having a small heat capacity or a thermal conductivity close to the atmosphere, such as a resin material or a ceramic material, so as not to affect the thermal state of the atmosphere.

  Further, when the flow velocity when the ambient atmosphere 2 on the surface of the object 1 flows is extremely small, the measurement values obtained by the temperature / humidity sensors 4a and 4b and the flow sensor 5 that detect the state in which the ambient atmosphere 2 flows through the rectifier tube 13 are obtained. It is necessary to take out large. Therefore, as shown in the perspective view of FIG. 13A and the cross-sectional view of FIG. 13B, the cross-sectional area of the rectifying tube 13 opposite to the object 1 surface is made smaller than the cross-sectional area of the object 1 surface side to increase the flow velocity. It is preferable to provide a temperature / humidity sensor 4b and a flow sensor 5 in the region to increase the measurement accuracy.

  Thus, when measuring changes in the temperature gradient and humidity gradient of the ambient atmosphere 2 relative to the surface of the object 1 and the flow state, the temperature / humidity sensor 4 and the flow sensor 5 can quickly detect the gas transport process, and the minute space It is desirable to use a sensor having a detection capability with resolution. As such a sensor, for example, a resistor formed in a fine structure with a thin film described in Japanese Patent No. 2889909, Japanese Patent No. 2621982, Japanese Patent No. 2780911 or Japanese Patent Laid-Open No. 6-18465 is used. What is necessary is just to use the sensor which it did.

  FIG. 14 shows a measuring means 12c in which a temperature / humidity sensor 4 and a flow sensor 5 using a thin-film resistor formed in a fine structure are formed integrally with a rectifying tube 13, wherein (a) is a perspective view and (b). (A) is a horizontal sectional view of (a), (c) is a vertical sectional view of (a). As shown in the cross-sectional view of (b), the measuring means 12c includes a plurality of resistors 16 formed in a fine structure with a thin film across the groove 14 of the substrate 15 having the groove 14 in the central portion in the vertical direction. A sensor sensitive part 17 is arranged, a cover 19 having a groove 18 is joined to the sensor sensitive part 17 in the center in the vertical direction, and the groove 15 of the substrate 15 and the groove 18 of the cover 19 are used as flow paths. The rectifying tube 13 is constituted by a cover 19. The substrate 15, the sensor sensitive portion 17 and the cover 19 can be easily manufactured by mass production with high accuracy by a so-called MEMS (Micro Electro Mechanical System) technology using an integrated circuit microfabrication technology. This measuring means 12c can be installed at different distances from the surface of the object 1 by arranging a plurality of sensor sensitive portions 17 in an array, and can be loaded with different capability ranges and different functions. Therefore, the size of the measurement can be reduced, the influence on the state of the surrounding atmosphere 2 is small, the installation position accuracy of the measurement location is high, and highly accurate measurement values can be obtained. Moreover, the restriction of the application location is widened, and versatility can be improved. Furthermore, it can unify into the sensor which outputs the output signal of the same level with the same kind, and the process of the processing apparatus 6 can be simplified.

  The measuring means 12c shown in FIG. 14 has been described with respect to the case where the temperature / humidity sensors 4a to 4c and the flow sensor 5 are arranged along the grooves 14 and 18 of the rectifying tube 13, that is, the substrate 15 and the cover 19, but FIG. As shown in FIG. 4, even when the temperature / humidity sensors 4a, 4b and the flow sensor 5 are arranged orthogonal to the wall surface of the rectifying tube 13, the temperature / humidity sensors 4a, 4b using resistors formed in a thin film with a fine structure are used. The flow sensor 5 can be formed integrally with the rectifying tube 13. As shown in the plan view of FIG. 15A and the cross-sectional view of FIG. 15B, the measuring means 12d forms a sensor substrate 22 having a plurality of through holes 21 having a constant cross-sectional area at the center of the wall 20. The temperature / humidity sensors 4a and 4b and the flow sensor 5 are formed by disposing a plurality of sensor sensitive portions 17 each having the resistor 16 on the through hole 21 of the sensor substrate 22. Also in this measuring means 12d, as in the case shown in FIG. 7 and FIG. 12B, the flow sensor 5 is preferably provided at a position away from the wall 20 which becomes the gas transport friction resistance to increase the measurement sensitivity. . For example, a sensor substrate 22 having a width of 1 mm, a length of 5 mm, and a thickness of 0.5 mm is installed at the center of the wall 20 having a length of 2 mm, and the temperature / humidity sensor 4b is disposed at a distance of 0.5 mm from the wall 20, When the temperature / humidity sensor 4a is arranged at a distance of 3 mm from the wall 20, the atmospheric state of 10 mm / second to 100 mm / second is measured from the change in the thickness δ of the boundary layer shown in FIG. Can do.

  Further, the measuring means 12d is formed by laminating the measuring means 12d as shown in the plan view of FIG. 16A and the side sectional view of FIG. 16B, whereby the rectifying function can be further improved. The measuring means 12d and 12e can also be easily manufactured by so-called MEMS technology using integrated circuit microfabrication technology.

  In the above description, the case where water vapor molecules aggregate and condense on the surface of the object 1 has been described. However, instead of the temperature / humidity sensor, a gas component sensor or gas concentration sensor is used to detect a gas component, density or concentration. By doing so, it can be applied to various fields such as purification and separation technology of multi-component gas.

  For example, in accordance with the measuring means 12 shown in FIG. 12, the rectifying tube 13 is formed of acrylic resin with an inner diameter of 11 mm and a length of 30 mm, and this rectifying tube 13 is arranged at a distance of 1 mm from the surface of the object 1, and the temperature / humidity sensor 4a Is mounted at a position 2 mm from the lower end of the rectifying tube 13, the temperature / humidity sensor 4 b is mounted at a position 15 mm from the lower end of the rectifying tube 13, and the temperature / humidity sensor 4 c is positioned 28 mm from the lower end of the rectifying tube 13. FIG. 17 to FIG. 19 show the results obtained by mounting and measuring the flow sensor 5 at an intermediate position between the temperature / humidity sensor 4a and the temperature / humidity sensor 4b. At the same time, a surface contact type dew condensation sensor based on the principle of detecting a change in electrical resistance value between electrodes due to adsorbed water of a measuring means conventionally used for performance comparison was mounted on the surface of the object 1 and measured.

FIG. 17 shows that the ambient atmosphere of the rectifier tube 13 is kept constant at 25 ° C. and 80% RH (dew point = 21.3 ° C.), and after 10 minutes, the surface temperature of the object 1 is lowered stepwise from 25 ° C. by 2 ° C. In this case, after 28 minutes, the surface temperature of the object 1 is at a dew point of 21.3 ° C. in the ambient atmosphere and is further lowered. The temperature / humidity sensor 4a and the temperature / humidity sensor 4b are affected by a decrease in the surface temperature of the object 1, and when the surface temperature of the object 1 is equal to or higher than the dew point of the external atmosphere, the temperature is further decreased and the relative humidity is further increased. When the surface temperature falls below the dew point of the ambient atmosphere, the relative humidity decreases. Further, since the temperature / humidity sensor 4a is closer to the surface of the object 1 than the temperature / humidity sensor 4b, when the surface temperature of the object 1 is equal to or higher than the dew point of the ambient atmosphere, the temperature is further decreased and the relative humidity is increased. When the temperature falls below the dew point of the ambient atmosphere, the reaction shows a decrease in relative humidity. Further, the behavior of the flow sensor 5 indicates that the flow toward the surface of the object 1 is increasing from the tendency before and after the dew point. Since the temperature / humidity sensor 4c is away from the surface of the object 1, it is not easily affected by a decrease in the surface temperature of the object 1 and is greatly influenced by the ambient atmosphere.
From the behavior of these temperature / humidity sensors 4a, 4b, 4c and the flow sensor 5, it can be seen that the phenomenon of dew condensation can be observed. With the occurrence of condensation on the surface of the object 1, the reaction start of the temperature / humidity sensor 4a and the temperature / humidity sensor 4b is 29 to 30 minutes, and the reaction start of the surface contact type condensation sensor is 32 minutes earlier. Therefore, the response is faster than that of the surface contact type dew condensation sensor, it can be detected in a non-contact manner, and a minute amount of dew condensation behavior can also be detected.

Further, FIG. 18 shows that the surface temperature of the object 1 is kept at 20 ° C., and the ambient atmosphere of the rectifying tube 13 is stepped by 5% RH from 25 ° C. and 60% RH (dew point = 16.7 ° C.) after 9 minutes. In this case, the dew point of the ambient atmosphere reaches 20 ° C. when 38 minutes have passed, and the temperature further increases. The temperature / humidity sensor 4c is not easily affected because it is away from the surface of the object 1, and shows that the relative humidity is increased due to the large influence of the humidity of the outside atmosphere. Since the temperature / humidity sensor 4a and the temperature / humidity sensor 4b are closer to the surface of the object 1, if the dew point of the outside atmosphere is equal to or higher than the surface temperature of the object 1, the water vapor is condensed when condensation occurs on the surface of the object 1, and the water vapor density is increased. The reaction is affected by the decrease and the relative humidity does not increase compared to the temperature / humidity sensor 4c. Further, the behavior of the flow sensor 5 indicates that the flow toward the surface of the object 1 is increasing from the tendency before and after the dew point.
From the behavior of these temperature / humidity sensors 4a, 4b, 4c and the flow sensor 5, it can be seen that the phenomenon of dew condensation can be observed. With the occurrence of condensation on the surface of the object 1, the reaction start of the temperature / humidity sensor 4a and the temperature / humidity sensor 4b is 38 minutes, and the reaction start of the surface contact type condensation sensor is 40 minutes earlier. Therefore, the response is faster than that of the surface contact type dew condensation sensor, it can be detected in a non-contact manner, and a minute amount of dew condensation behavior can also be detected.

FIG. 19 shows that the external atmosphere of the rectifying tube 13 is kept constant at 25 ° C. and 80% RH (dew point = 21.3 ° C.), and the surface temperature of the object 1 is maintained at 19 ° C. to generate condensation. When the surface temperature of the object 1 is increased to 25 ° C. after a lapse of minutes, the condensed water is evaporated as water vapor.
When the surface temperature of the object 1 starts to rise from 19 ° C. to 25 ° C., water vapor desorption is promoted, and the temperature / humidity sensor 4a and the temperature / humidity sensor 4b show a reaction of increasing relative humidity, and transpiration is observed. Since the temperature / humidity sensor 4a is closer to the surface of the object 1 than the temperature / humidity sensor 4b, the rate of increase per hour is high. The behavior of the flow sensor 5 indicates that the flow in the direction opposite to the surface of the object 1 increases from the tendency before and after the surface temperature of the object 1 increases.
It can be seen that the transpiration phenomenon can be observed from the behavior of the temperature and humidity sensors 4a, 4b, 4c and the flow sensor 5. The temperature / humidity sensor 4a and the temperature / humidity sensor 4b show an increase in relative humidity until 40 minutes have elapsed, indicating that condensation has occurred, and 33 minutes from 7 minutes to 40 minutes is a transpiration process. It is obvious from the temperature / humidity behavior of the temperature / humidity sensor 4c, and the temperatures of the temperature / humidity sensor 4a and the temperature / humidity sensor 4b increase as the surface temperature of the object 1 increases. It shows that the humidity value decreases. The occurrence of transpiration from the surface of the object 1 is 8 minutes when the reaction of the temperature / humidity sensor 4a and the temperature / humidity sensor 4b starts, and is earlier than the reaction of the surface contact type condensation sensor is 12 minutes. However, the reaction of the surface contact type dew condensation sensor at 12 minutes showed that the dew condensation disappeared, but in actuality, the dew condensation state was maintained until 40 minutes. Therefore, the response is faster than the surface contact type dew condensation sensor, it can be detected in a non-contact manner, and a very small amount of transpiration behavior can be detected in real time.

  In this way, using the non-contact dew condensation detection device 3 capable of detecting the moisture transpiration behavior in real time, the behavior of moisture transpiration from the recording paper onto which the image has been transferred is detected and heated and pressurized by the fixing device. An image forming apparatus that prevents deformation such as curling that sometimes occurs on recording paper will be described.

  As shown in the configuration diagram of FIG. 20, the image forming unit 30 of the image forming apparatus is provided with a charging device 32 disposed around the photosensitive drum 31, a laser light source, a polygon mirror, and the like. A writing device 33 for writing an image by irradiating a beam, a developing device 34, a transfer device 35, a cleaning device 36, a heating roller 37 and a pressure roller 38, and fixing the toner image transferred to the recording paper 39. The fixing device 40 is provided.

  The image forming unit 30 forms an electrostatic latent image by irradiating the surface of the photosensitive drum 31 charged by the charging device 32 with a laser beam by the writing device 33, and the formed electrostatic latent image is visualized by the developing device 34. Thus, a toner image is formed. The toner image formed on the photosensitive drum 31 is transferred by the transfer device 35 to the recording paper 39 fed from the paper feeding device or the manual feed tray. The toner remaining on the photosensitive drum 31 having the toner image transferred to the recording paper 39 is removed by the cleaning device 36. The recording paper 39 onto which the toner image has been transferred is sent to a fixing device 40 where heat and pressure are applied to fix the toner image. The recording paper 39 on which the image is fixed is discharged to a paper discharge device. When the fixing device 40 applies heat and pressure to the recording paper 39 to fix the toner image, the recording paper 39 is drastically dried and deformation such as curling occurs. The drying speed of the recording paper 39 is governed by the transpiration behavior of moisture contained in the recording paper 39.

  A state in which the recording paper 39 is deformed by the evaporation behavior of moisture contained in the recording paper 39 will be described. As shown in the schematic diagram of FIG. 21, when the recording paper 39 moves on the high temperature heating member 401, the temperature of the heating member 401 is changed, and the non-contact dew condensation detection device 3 detects the moisture contained in the recording paper 39. The transpiration behavior was examined and the results are shown in FIGS. In FIG. 22, the transpiration A characteristic is when the contact temperature difference between the heating member 401 and the recording paper 39 is 60 ° C., and the transpiration B characteristic is when the contact temperature difference between the heating member 401 and the recording paper 39 is 70 ° C. When the contact temperature difference between the heating member 401 and the recording paper 39 is 80 ° C., the transpiration D characteristic indicates that the contact temperature difference between the heating member 401 and the recording paper 39 is 90 ° C. FIG. FIG. 22 (b) shows a change in the temperature rise of the recording paper 39 with respect to the heating time, FIG. 22 (b) shows a change in the amount of increase in moisture evaporation contained in the recording paper 39 with respect to the heating time of the recording paper 39, and FIG. The change of the displacement amount δ of the recording paper 39 with respect to the heating time of 39 is shown. FIGS. 23A to 23D show changes in the temperature rise, moisture transpiration increase, and displacement of the recording paper 39 for each transpiration A characteristic, transpiration B characteristic, transpiration C characteristic, and transpiration D characteristic.

  As shown in FIGS. 22A and 22B, when the recording paper 39 is heated and the temperature rises, the moisture contained in the recording paper 39 evaporates, and the contact temperature difference between the heating member 401 and the recording paper 39 is 60 ° C. As the temperature increases to 90 ° C., the transpiration rate and transpiration rate (transpiration rate per hour) gradually increase, and the transpiration rate decreases when transpiration to some extent. Then, as shown in FIGS. 22B and 22C, the displacement amount δ of the recording paper 39 is larger and the deformation amount is faster as the moisture evaporation rate is larger. For this reason, the amount of moisture contained in the recording paper 39 affects the magnitude of deformation of the recording paper 39, and the deformation amount of the recording paper 39 is determined by the moisture evaporation rate.

  Further, although the moisture evaporates from the recording paper 39, the recording paper 39 may not be displaced like the transpiration A characteristic. This indicates that it depends on the strength (stiffness) of the recording paper 39. In other words, the deformation is prevented by the strength of the recording paper 39, and the deformation does not occur immediately even when moisture evaporates. Therefore, even if the amount of moisture contained in the recording paper 39 is large, the amount of deformation can be reduced by slowing the transpiration rate, that is, by slowly drying the recording paper 39.

  Further, the deformation of the recording paper 39 due to the transpiration behavior of the moisture contained in the recording paper 39 is maintained by the strength of the recording paper 39 at the start of the deformation of the recording paper 39 as shown in FIGS. It occurs after the start of transpiration of moisture, and the amount of deformation increases in descending order of transpiration rate. Therefore, the deformation amount of the recording paper 39 can be predicted by measuring the evaporation rate before the recording paper 39 is deformed. Therefore, the deformation amount of the recording paper 39 from the deformation start time to 0.1 seconds with respect to the transpiration rate before the deformation of the recording paper 39 from the time when the moisture contained in the recording paper 39 starts to 0.1 seconds is shown in FIG. 24. As shown in FIG. 24, the degree of deformation of the recording paper 39 is clarified by measuring the transpiration rate from the start of transpiration before the recording paper 39 is deformed to 0.1 second.

  From the above, the deformation amount of the recording paper 39 can be determined by measuring the transpiration rate of the recording paper 39. If the transpiration start time and the transpiration rate before deformation are measured with respect to the temperature given to the recording paper 39, The deformation of the recording paper 39 can be predicted.

  Next, FIG. 25 shows changes in the amount of moisture transpiration and displacement of different types of recording paper 39 when the contact temperature difference between the heating member 401 and the recording paper 39 is 70 ° C. In FIG. 25, the transpiration E characteristic is a case in which the recording paper 39 is thinner than the transpiration B characteristic, and the paper has a small heat capacity and water easily evaporates. As shown in FIGS. 25A and 25B, the transpiration E characteristic evaporates earlier than the transpiration B characteristic and deforms faster. That is, it shows that the recording paper 39 is thicker (the strength of the stiffness). Therefore, by detecting the transpiration behavior of moisture contained in the recording paper 39, that is, the transpiration rate, the transpiration start time and the temperature, even if the plain paper excluding special paper such as coated paper is recycled paper, for example, It is possible to predict the deformation of the recording paper 39 and determine the deformation amount without having to determine the type of the paper 39.

  Therefore, in order to detect the transpiration behavior of the recording paper 39 in the paper conveyance path of the image forming unit 30, the first position sensor 41a and the non-contact dew condensation detection device are located upstream of the transfer device 35 as shown in FIG. 3 has the same first measuring means 42a as the measuring means 12c shown in FIG. 14, for example, and has a second position sensor 41b and a second measuring means 42b on the downstream side of the transfer device 35 in the paper transport path, The fixing device 40 includes a third measuring unit 42c. The first position sensor 41a and the first measuring means 42a are arranged at substantially the same position, and the second position sensor 41b and the second measuring means 42b are also arranged at substantially the same position.

  As shown in the block diagram of FIG. 26, the control device of the image forming apparatus includes a deformation prediction control unit 43 that predicts deformation of the recording sheet 39 based on the detection results of the position sensors 41a and 41b and the measuring units 42a to 42c. . The deformation prediction control unit 43 includes a transpiration behavior calculation processing unit 44, a timer unit 45, a reference information storage unit 46, a deformation prediction processing unit 47, and a deformation avoidance control unit 48. The transpiration behavior calculation processing unit 44 detects the transpiration behavior of moisture contained in the recording paper 39 based on the measurement signals output from the first measurement means 42a, the second measurement means 42b, and the third measurement means 42c, and transpiration. The amount is calculated, and the transpiration rate of moisture from the recording paper 39 is calculated from the calculated transpiration amount and the time difference when the leading edge of the recording paper is detected by the first position sensor 41a and the second position sensor 41b. In the reference information storage section 46, reference characteristics indicating the temperature rise, transpiration increase amount and displacement amount with respect to the heating time of the recording paper 39 as shown in FIG. 23, and before the recording paper 39 is deformed as shown in FIG. The reference value of the transpiration rate is stored in advance for a certain period of time from the start of transpiration until deformation occurs, for example, 0.1 seconds. The deformation prediction processing unit 47 compares the transpiration rate calculated by the transpiration behavior calculation processing unit 44 with the reference value stored in the reference information storage unit 46 to predict the deformation of the recording paper 39 and at the fixing device 40 the moisture transpiration amount. Determine how much will increase. The deformation avoidance control unit 48 inputs the conveyance speed information of the recording paper 39 and the fixing temperature information of the fixing device 40, and predicts the deformation of the recording paper 39 sent from the deformation prediction processing unit 46 using the input conveyance speed information and fixing temperature information. The control information of the conveyance speed and the fixing temperature of the recording paper 39 is generated by varying the reference characteristics indicating the temperature rise, the transpiration increase amount and the displacement amount with respect to the heating time stored in the information and reference information storage unit 46. If there is an abnormality in the deformation prediction information of the recording paper 39 output from the deformation prediction processing section 47 and sent from the deformation prediction processing section 47, the amount of transpiration, and the control information of the conveyance speed and the fixing temperature, the recording paper is output. 39 is stopped and an alarm signal is output to the alarm unit 51.

  The deformation prediction control unit 43 predicts the deformation that occurs in the recording paper 39 that is transferred to the fixing device 40 by transferring the toner image that is sent to the image forming unit 30 and formed on the photosensitive drum 31 and avoids the deformation. The processing to be performed will be described with reference to the flowchart of FIG.

When the first position sensor 41a detects the leading end of the recording paper 39 that has been transported after the image forming process is started in the image forming unit 30 (step S21), the transpiration behavior calculation processing unit 44 then starts from the time measuring unit 45. The output time t0 is input (step S22), and the recording sheet 39 measured by the first measuring unit 42a at a predetermined timing determined by the arrangement of the first position sensor 41a and the first measuring unit 42a. The transpiration amount H0 is calculated from the measurement information indicating the transpiration behavior of the moisture contained in the tip (step S23). When the toner image is transferred to the recording paper 39 conveyed in this state by the transfer device 35 and sent to the fixing device 40, the leading end of the recording paper 39 to which the toner image has been transferred is detected by the second position sensor 41b. When detected (step S24), the transpiration behavior calculation processing unit 44 inputs the time t1 at that time from the time measuring unit 45 (step S25), and the recording sheet 39 measured by the second measuring means 42b at a predetermined timing. The transpiration amount H1 is calculated from the measurement information indicating the transpiration behavior of the water contained in the tip (step S26). When the transpiration behavior calculation processing unit 44 calculates the transpiration amount H1 from the measurement information measured by the second measuring means 42b, the previously calculated transpiration amount H0, the transpiration amount H1 calculated this time, the first position sensor 41a and the second position sensor 41a. The transpiration rate V from time t0 and time t1 when the position sensor 41a detects the leading edge of the recording paper 39,
V = (H1-H0) / (t1-t0)
And the calculated transpiration rate V is sent to the deformation prediction processing unit 47 (step S27).

  In this way, the transpiration behavior of the moisture contained in the leading end portion of the recording paper 39 is measured because the end portion of the recording paper 39 conveyed to the image forming unit 30 has good ventilation and transpiration to the surrounding atmosphere is large. This is because the drying tends to proceed and the water supply to the end tends to be insufficient, so that the drying behavior appears quickly and greatly affects the deformation of the recording paper 39. The transpiration behavior is measured when the leading end of the recording paper 39 reaches the position of the first position sensor 41a and the second position sensor 41b, because the recording paper 39 is being conveyed. This is to measure the transpiration behavior at a point to obtain an accurate transpiration rate.

  The deformation prediction processing unit 47 sends the transpiration rate V and the reference value of the transpiration rate from the start of transpiration before the deformation of the recording paper 39 stored in the reference information storage unit 46 to a certain time until the deformation occurs. When the transpiration speed V is smaller than the reference value, it is determined that the recording paper 39 being conveyed is not deformed. When the transpiration speed V is equal to or higher than the reference value, the recording paper 39 being conveyed is determined. It is determined that deformation will occur, and deformation prediction information is sent to the deformation avoidance control unit 48 (step S28). When the deformation prediction information is sent, the deformation avoidance control unit 48 inputs the conveyance speed information of the recording paper 39 and the fixing temperature information of the fixing device 40, and the recording paper 39 of the recording paper 39 to which the input conveyance speed information and the fixing temperature information are sent. Control information for the conveyance speed and fixing temperature of the recording paper 39 is generated by varying the reference characteristics indicating the temperature rise, the transpiration increase amount, and the displacement amount with respect to the heating time stored in the deformation prediction information and reference information storage unit 46 to generate the recording paper. 39 is output to the conveyance speed controller 49 and the fixing temperature controller 50 (step S29). The conveyance speed control unit 49 and the fixing temperature control unit 50 control the conveyance speed of the recording paper 39 and control the fixing temperature of the fixing device 40 based on the sent conveyance speed and fixing temperature control information. When the conveyance speed and the fixing temperature are controlled to avoid deformation of the recording paper 39, if there is an abnormality in the control information of the conveyance speed and the fixing temperature, the conveyance of the recording paper 39 is stopped and an alarm signal is sent to the alarm unit 51. Is output (steps S30 and S31).

  Thus, before the recording paper 39 is sent to the fixing device 40, the evaporation rate V of the moisture contained in the recording paper 39 is calculated to predict the presence or absence of deformation and the deformation avoiding process is performed. It is possible to prevent the sheet jam from occurring by preventing the sheet from being deformed when heated.

  When the leading end of the recording paper 39 reaches the fixing device 40 and the measurement information indicating the transpiration behavior of moisture contained in the leading end of the recording paper 39 is input from the third measuring means 42c to the transpiration behavior calculating unit 44, the transpiration behavior calculation is performed. The unit 44 calculates the transpiration amount H2 from the input measurement information and sends it to the deformation avoidance control unit 48. The deformation avoidance control unit 48 compares the transpiration amount H2 sent with the reference characteristics indicating the temperature rise, the transpiration increase amount and the displacement amount with respect to the heating time stored in the reference information storage unit 46, and the transpiration amount H2 increases more than a predetermined value. If so, an alarm signal is output to the alarm unit 51.

  Thus, by calculating the transpiration amount H2 of the recording paper 39 fixed by the fixing device 40 with the measurement information of the third measuring means 42c, the presence or absence of deformation of the recording paper 39 can be finally confirmed. In other words, the recording paper 39 conveyed to the image forming unit 30 gradually increases in temperature as it is conveyed to the fixing device 40, and due to this temperature increase, the amount of transpiration of moisture contained in the recording paper 39 gradually increases. When passing, the temperature becomes highest and the amount of transpiration increases. Therefore, from the measurement information of the third measuring means 42c, the transpiration amount H2 of the recording paper 39 that has entered the fixing device 40 can be calculated to estimate how much the transpiration amount increases in the fixing device 40.

  Further, by using, for example, the measuring means 12c shown in FIG. 14 of the non-contact dew condensation detecting device 3 as the first measuring means 42a to the third measuring means 42c, the transpiration behavior is measured in a non-contact manner on the recording paper 39. The transpiration behavior can be measured without affecting the toner image transferred to the recording paper 39, and the transpiration amount can be obtained in real time. Furthermore, since the measuring means 12c shown in FIG. 14 of the non-contact dew condensation detection device 3, for example, constitutes the rectifying tube 13, the transpiration is accurately performed without giving fluctuation to the transpiration flow at the measurement position by the recording paper 39 conveyed. The behavior can be measured.

  As shown in FIG. 28, the first measuring unit 42a and the second measuring unit 42b are incorporated in the conveying roller 52 in the conveying path of the recording paper 39, so that the distance from the recording paper 39 can be accurately maintained. it can. Further, the first measuring means 42a and the second measuring means 42b may be provided in the vicinity of the conveying roller 52. When a conveying belt is used as the conveying means, the first measuring means 42a and the second measuring means 42b are separated from the conveying belt by a certain position. A first measuring unit 42a and a second measuring unit 42b may be provided.

  Furthermore, in the above description, the case where the measurement means 12c shown in FIG. 14 is used as the first measurement means 42a to the third measurement means 42c, for example, has been described. However, the measurement means 12a shown in FIG. 12 or the measurement means shown in FIG. 12b or measuring means 12d shown in FIG. 15 may be used.

  Further, as shown in the front view of FIG. 29 (a) and the cross-sectional view of FIG. 29 (b), the temperature / humidity sensors 4a, 4b and the flow sensor 5 are mounted on the sensor substrate 22 having the cavity 53 at the mounting position. 4b and the flow sensor 5 are provided along the flow direction of moisture transpiration, and the measurement means 12f having flow path plates 54 for suppressing fluctuation of the transpiration flow on both sides of the sensor substrate 22 is provided as the first measurement means 42a to the third measurement means 42a. You may use for the measurement means 42c.

  Further, as shown in the perspective view of FIG. 30A and the cross-sectional view of FIG. 30B, pyroelectric elements such as a thermopile and an infrared sensor having a pyroelectric structure are formed on the upper surface 22a of the sensor substrate 22 along the conveyance direction of the recording paper 39. The element 54, the temperature / humidity sensors 4a and 4b, and the flow sensor 5 are arranged, the heat radiating element 55 is arranged at a position facing the pyroelectric element 54 on the lower surface 22b of the sensor substrate 22, and the center of the sensor substrate 22 is removed by etching or the like. Thus, the measuring means 12g provided with the gap 56 through which the side end portion of the recording paper 39 passes may be used for the first measuring means 42a to the third measuring means 42c. When this measuring means 12g is used for the first measuring means 42a to the third measuring means 42c, the heat radiated from the heat radiating element 55 is detected by the pyroelectric element 54 across the gap 56. When the recording paper 39 is transported into the gap 56, a slight temperature, for example, in a minute range at the end of the recording paper 39 due to the heat of a small amount of heat radiated from the heat radiating element 55, for example, several tens of msec, for example several tens of mW. The temperature rises by about 0.1 ° C, and a minute range of water evaporates. By measuring the behavior of this transpiration with the temperature / humidity sensors 4a and 4b and the flow sensor 5, the transpiration amount and temperature can be measured. Further, when the recording paper 39 is conveyed to the gap 56, the pyroelectric element 54 detects the amount of infrared light transmitted through the recording paper 39, whereby the quality (fiber density) and moisture content of the recording paper 39 can be measured. Prediction accuracy of sheet deformation can be increased.

  Further, the position sensor 41 may be provided on the sensor substrate 22. By providing the position sensor 41 on the sensor substrate 22 in this way, it is possible to reliably detect the transpiration behavior of the front end portion of the recording paper 39.

  In the above description, the case where the transpiration behavior calculation processing unit 44, the deformation prediction processing unit 47, and the deformation avoidance control unit 48 are provided in the deformation prediction control unit 43 has been described. However, as shown in the block diagram of FIG. The functions of the unit 44, the deformation prediction processing unit 47, and the deformation avoidance control unit 48 may be processed by the CPU 57. In this case, the measurement information of the position sensors 41a and 41b and the measuring means 42a to 42c is input from the input unit 58 to the CPU 57, and the CPU 57 performs transpiration behavior calculation processing, deformation prediction processing, and deformation avoidance processing, and outputs the processing results. The sheet 59 is sent to the conveyance speed control unit 49 and the fixing temperature control unit 50 to correct the conveyance speed and fixing temperature of the recording paper 39 to prevent the recording paper 39 from being deformed.

  Further, although the case where the first measuring unit 42a and the second measuring unit 42b are provided on the upper side of the conveyance path of the recording paper 39 has been described, each measuring unit 12 of the non-contact dew condensation detection device 3 is small and has a high-speed response. Therefore, the transpiration amount may be obtained by detecting the transpiration behavior that evaporates from the lower side of the recording paper 39 by arranging it below the conveyance path of the recording paper 39.

  In the above description, the electrophotographic image forming apparatus has been described. However, the present invention can be similarly applied to other types of image forming apparatuses such as an ink jet system to prevent a recording paper conveyance failure such as a paper jam.

It is a schematic diagram which shows the behavior of the surrounding atmosphere with respect to the object surface. It is a distribution map of the temperature and relative humidity of the ambient atmosphere that changes according to the distance from the object surface of the ambient atmosphere to the surface temperature of the object. It is a block diagram which shows the structure of the non-contact dew condensation detection apparatus of this invention. It is a block diagram of the 1st measurement means which has arrange | positioned the temperature humidity sensor and the flow sensor with respect to the object surface. It is a flowchart which shows a process when detecting the dew condensation generation | occurrence | production of the object surface. It is a flowchart which shows a process when detecting transpiration | evaporation generation | occurrence | production from an object surface. It is a block diagram of the 2nd measurement means. It is a change characteristic figure of the thickness of a boundary layer with respect to the distance along a wall surface. It is a block diagram of the 3rd measurement means. It is a distribution map of the temperature and humidity of the ambient atmosphere above and below the object surface. It is a block diagram of the 4th measurement means. It is sectional drawing which shows the structure of a 5th measurement means and a 6th measurement means. It is a block diagram of the 7th measurement means. It is a block diagram of the 8th measurement means. It is a block diagram of the 9th measurement means. It is a block diagram of the 10th measuring means. It is a change characteristic figure of temperature and humidity measured by the 5th measurement means. It is a temperature-humidity change characteristic view measured on the 2nd condition by the 5th measurement means. It is a temperature-humidity change characteristic view measured on the 3rd condition by the 5th measurement means. It is a block diagram showing an image forming unit of the image forming apparatus of the present invention. It is a schematic diagram which shows the deformation | transformation by the evaporation of the water | moisture content contained in a recording paper. FIG. 6 is a change characteristic diagram of a sheet temperature rise, a displacement amount, and a moisture transpiration increase amount with respect to a recording sheet heating time. It is a change characteristic figure of the paper temperature rise with respect to the recording paper heating time for every different transpiration characteristic, the amount of displacement, and the amount of moisture transpiration increase. It is a change characteristic figure of the paper temperature rise with respect to the recording paper heating time for every different transpiration characteristic, the amount of displacement, and the amount of moisture transpiration increase. It is a change characteristic view of the displacement amount of the recording paper with respect to the transpiration rate. It is a change characteristic view of the amount of displacement and the amount of increase in water evaporation with respect to the recording paper heating time of different types of recording paper. It is a block diagram which shows the structure of a deformation | transformation prediction control part. 6 is a flowchart illustrating a recording sheet deformation prediction / avoidance process in the image forming unit. It is a perspective view which shows arrangement | positioning of the measurement means with respect to a recording paper. It is a block diagram of the 11th measurement means. It is a block diagram of the 12th measurement means. It is a block diagram which shows the structure of another deformation | transformation prediction control part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Object, 2; Ambient atmosphere, 3; Non-contact dew condensation detection apparatus, 4; Temperature humidity sensor,
5; flow sensor, 6 ;, 7; operation unit, 8; arithmetic processing unit, 9; storage unit,
10; Alarm output unit, 11; Wall surface, 12; Measuring means, 13; Rectifier tube, 15;
16; Resistor, 17; Sensor sensitive part, 19; Cover, 20; Wall, 21;
22; sensor substrate, 30; image forming unit, 31; photosensitive drum,
32; Charging device; 33; Writing device; 34; Developing device; 35; Transfer device;
36; Cleaning device; 39; Recording paper; 40; Fixing device; 41; Position sensor;
42; measurement means, 43; deformation prediction control unit, 44; transpiration behavior calculation processing unit,
45; time measuring unit, 46; reference information storage unit, 47; deformation prediction processing unit,
48; deformation avoidance control unit; 49; transport speed control unit; 50; fixing temperature control unit;
51; alarm unit, 52; transport roller, 53; 54; pyroelectric element, 55; heat dissipation element,
57; CPU.

Claims (18)

  The ambient temperature measured by measuring the distribution and transport process of the ambient atmosphere on the object surface by combining any of the elements of temperature, humidity, flow direction, flow velocity, pressure, and component in the ambient atmosphere of the object surface or a combination of each element. Non-contact dew condensation characterized by detecting the behavior of the ambient atmosphere gas adsorbing and agglomerating on the object surface and the behavior of the agglomerated liquid evaporating on the object surface based on the distribution of the atmosphere on the object surface and the transport process Detection method.   2. The non-contact dew condensation detection method according to claim 1, wherein each element of the gas in the ambient atmosphere is measured at least at two locations in the vicinity of the object surface and at a distance from the object surface. .   3. The non-contact dew condensation detection method according to claim 1 or 2, wherein a wall surface having a frictional resistance with respect to the gas in the ambient atmosphere is placed close to the object surface at a place where each element of the gas in the ambient atmosphere is measured. And a non-contact dew condensation detection method, which is arranged in the direction in which the gas in the surrounding atmosphere flows.   3. The non-contact dew condensation detection method according to claim 2, wherein the location where each element of the gas in the ambient atmosphere is measured is measured in a direction in which the transport components of the gas along the gravity oppose each other, and the transport of the gas along the gravity is performed. It is characterized by detecting the behavior of the ambient atmosphere gas adsorbing and aggregating on the object surface and the behavior of the agglomerated liquid evaporating on the object surface based on the difference between the measured values measured in the directions where the components are opposite to each other. Contact condensation detection method.   2. The non-contact dew condensation detection method according to claim 1, wherein a wall having a frictional resistance against the gas in the ambient atmosphere is close to the surface of the object at a place where each element of the gas in the ambient atmosphere is measured, A non-contact dew condensation detection method which is arranged in a direction in which an atmospheric gas flows, and measures each element of the gas in the ambient atmosphere at at least two locations in the vicinity of the wall surface and remote from the object surface.   6. The non-contact dew condensation detection method according to claim 3 or 5, wherein the wall surface is formed by a rectifier tube formed in a cylindrical shape.   7. The non-contact dew condensation detection method according to claim 6, wherein an inner diameter of a part of the rectifying pipe is reduced. Having a measuring means and a processing device;
The measurement means is disposed at least at two locations in the vicinity of the object surface and remote from the object surface, and a temperature / humidity sensor for measuring the temperature and humidity of the gas in the ambient atmosphere of the object surface, and the gas in the ambient atmosphere of the object surface A flow sensor for measuring the flow direction or flow velocity of
The processing apparatus determines the distribution state and transport process of the ambient atmosphere on the object surface based on the measurement results of the temperature / humidity sensor and the flow sensor, and adsorbs and aggregates the ambient atmosphere gas on the object surface and on the object surface. A non-contact dew condensation detection device that detects the behavior of transpiration of liquid that has been condensed.   9. The non-contact dew condensation detection device according to claim 8, wherein the measurement means is provided in a rectifying tube arranged close to the object surface. Having a measuring means and a processing device;
The measuring means is arranged in two locations, a rectifying tube arranged close to the object surface, a vicinity of the wall surface of the rectifying tube, and a distance from the wall surface, and the temperature and humidity of the gas in the ambient atmosphere of the object surface are measured. A temperature / humidity sensor to be measured, and a flow sensor for measuring the flow direction or flow velocity of gas in the rectifying pipe,
The processing apparatus determines the distribution state and transport process of the ambient atmosphere on the object surface based on the measurement results of the temperature / humidity sensor and the flow sensor, and adsorbs and aggregates the ambient atmosphere gas on the object surface and on the object surface. A non-contact dew condensation detection device that detects the behavior of transpiration of liquid that has been condensed.   11. The non-contact dew condensation detection device according to claim 8, wherein the measurement unit includes a sensor for measuring a pressure and a component of a gas in an ambient atmosphere around the object surface.   The transpiration rate of volatile components contained in various papers is measured by the non-contact dew condensation detection method according to any one of claims 1 to 7, and a transpiration rate that is a transpiration rate per unit time is calculated from the measured evaporation amount. A paper deformation suppression method, wherein the drying condition of the paper is set so that the calculated transpiration rate does not exceed a preset reference value of the transpiration rate until a predetermined time until the paper is deformed.   13. The sheet deformation suppressing method according to claim 12, wherein when the sheet is conveyed, the amount of volatile component contained in the leading edge of the sheet is measured at a plurality of locations along the sheet conveyance path. A method for suppressing sheet deformation.   12. A non-contact dew condensation detection device according to claim 8, wherein the amount of moisture contained in the recording paper is measured while the recording paper on which an image is to be formed is conveyed, and a unit time is determined from the measured evaporation amount. The transpiration rate, which is the amount of transpiration per unit, is calculated, and the drying condition of the recording paper is set so that the calculated transpiration rate does not exceed the preset reference value of the transpiration rate until a predetermined time until the recording paper is deformed. An image forming apparatus, wherein   15. The image forming apparatus according to claim 14, wherein the amount of transpiration of water contained in the leading end portion of the recording paper is measured at a plurality of locations along a conveyance path of the recording paper. A plurality of measurement means and a deformation prediction control device of the non-contact dew condensation detection device according to any one of claims 8 to 11,
The plurality of measuring means are arranged at a plurality of locations along the conveyance path of the recording paper,
The deformation prediction control device includes a transpiration behavior calculation processing unit, a deformation prediction processing unit, and a deformation avoidance control unit, and the transpiration behavior calculation processing unit is configured to detect the recording paper based on measurement signals output from the plurality of measurement units. Detecting the transpiration behavior of moisture contained in the tip, calculating the transpiration amount, calculating the transpiration rate that is the transpiration rate per unit time from the calculated transpiration amount, the deformation prediction processing unit is the transpiration behavior calculation processing unit Compare the transpiration rate calculated in step 1 with the reference value of the transpiration rate up to a certain time until the recording paper is deformed in advance, and when the calculated transpiration rate exceeds the reference value, the recording being conveyed It is determined that the sheet is deformed and generates deformation prediction information, and the deformation avoidance control unit generates either the recording sheet conveyance speed or the fixing temperature based on the deformation prediction information generated by the deformation prediction processing unit. Image forming apparatus characterized by variably controlling both. A plurality of measuring means and a CPU of the non-contact dew condensation detecting device according to any one of claims 8 to 11,
The plurality of measuring means are arranged at a plurality of locations along the conveyance path of the recording paper,
The CPU detects a transpiration behavior of moisture contained in the leading end portion of the recording paper based on measurement signals output from the plurality of measuring means, calculates a transpiration amount, and transpiration per unit time from the calculated transpiration amount. Calculate the transpiration rate as a quantity, compare the calculated transpiration rate with the preset reference value of the transpiration rate until a certain time until the recording paper is deformed, and the calculated transpiration rate exceeds the reference value An image forming apparatus comprising: determining that deformation occurs in the recording sheet being conveyed, and variably controlling one or both of the recording sheet conveyance speed and the fixing temperature.   18. The image forming apparatus according to claim 16, wherein the measuring unit includes a position sensor that detects a leading edge of the recording paper.

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