Information processing system, storage medium, and information processing method

Abstract

An information processing system, a storage medium, and an information processing method are provided, and the information processing system includes a processor and a sensor device that irradiates a target sheet with light and detects light of an absorption band caused by H-O-H stretching movement that has passed through the sheet. The processor performs: a process for obtaining absorption information indicating the amount of absorption of the paper on the absorption band on the basis of the detection result of the sensor device; and using a prediction model for predicting the expansion and contraction rate of the paper sheet on the basis of the absorption information of the absorption band in the paper sheet, and obtaining the expansion and contraction rate of the paper sheet corresponding to the obtained absorption information.

Description

Technical Field

[0001] The invention relates to an information processing system, a storage medium and an information processing method. Background Art

[0002] Paper expands and contracts according to the humidity of the environment. The property of how much paper expands and contracts according to changes in humidity is called humidity expansion rate. The paper industry standard called JAPAN TAPPI No. 28 "Paper and paperboard - Test method for expansion and contraction due to humidity changes" defines humidity expansion rate and stipulates its measurement method. Japanese Industrial Standards or international standards organizations also have standards for the expansion and contraction rate of paper corresponding to humidity.

[0003] The expansion and contraction rate of paper affects the printing quality, such as the occurrence of paper jams on the paper conveying path and the occurrence of curling caused by fixing. The expansion and contraction rate of paper varies greatly depending on the deviation of the conditions of each paper manufacturing batch, such as the difference in the manufacturing factory or the season, or the environment in which the paper is used.

[0004] In the method for measuring the expansion ratio specified in the standard, the humidity of the environment in which the paper is placed is changed stepwise, the paper is adjusted to the humidity at each humidity, and then the paper size is measured. Therefore, the measurement requires a lot of time.

[0005] Although there is no direct relationship with the expansion and contraction rate of paper in response to humidity, there are technologies disclosed in Patent Documents 1 to 3 as technologies for predicting the contraction of paper due to heating in the fixing unit and using it for control of double-sided printing.

[0006] The device disclosed in Patent Document 1 comprises: a temperature measuring unit for measuring the internal temperature of a machine; an image forming unit for forming a toner image and transferring it to a paper; a fixing unit for fixing the toner image on the paper; a paper discriminating unit as a first detecting unit for detecting the size of the paper before passing through the fixing unit; a paper reading unit as a second detecting unit for detecting the size of the paper after passing through the fixing unit; a shrinkage rate calculating unit for calculating the shrinkage rate of the paper based on the detection results of the first detecting unit and the second detecting unit; a storage unit for storing shrinkage rate data of each internal environment of the machine in which the internal temperature environment of the machine is correspondingly associated with the shrinkage rate of the paper; and an image correction unit for correcting the forming conditions of the toner image based on the shrinkage rate of the paper stored in the storage unit in correspondence with the internal temperature of the machine measured by the measuring unit.

[0007] The device disclosed in Patent Document 2 comprises: a transfer unit that transfers an image formed in an image forming unit to a sheet of paper; a fixing unit that fixes the image transferred to the sheet of paper by heating the sheet of paper conveyed from the transfer unit; and a re-feeding path that conveys the sheet of paper passing through the fixing unit to the transfer unit again. In addition, the device comprises: a detection unit that is arranged at the downstream side of the fixing unit in the sheet conveying direction and detects the internal environment of the machine or the characteristics of the sheet of paper; and a correction value calculation unit that calculates the expected expansion and contraction rate of the sheet of paper when the back image of the transfer unit is transferred based on the value detected by the detection unit.

[0008] The device disclosed in Patent Document 3 comprises: a sensor for acquiring characteristics of a paper to be printed on both sides in an image forming device for double-sided printing that prints an image on the front side of an original on the front side of the paper and then prints an image on the back side of the paper; a shrinkage rate acquisition component for acquiring, based on the acquired characteristics of the paper, a shrinkage rate of the paper indicating the ratio of the shrinkage of the paper that occurs from the time the image on the front side is printed to the time the image on the back side is printed; and a correction component for correcting image data corresponding to the image on the back side based on the acquired shrinkage rate.

[0009] Patent Document 4 discloses a technique for measuring the orientation of fibers of paper or the like by transmitting near infrared rays through paper or the like and analyzing the transmitted light.

[0010] Patent Document 1: Japanese Patent Application Publication No. 2021-105629

[0011] Patent Document 2: Japanese Patent Application Publication No. 2019-45740

[0012] Patent Document 3: Japanese Patent Application Publication No. 2009-128874

[0013] Patent Document 4: Japanese Patent Application Laid-Open No. 7-243187

[0014] Measuring the expansion ratio using the method specified in the standard requires a dedicated measuring device and takes a long time. When you want to know the expansion ratio of a piece of paper quickly, such as when you want to know the expansion ratio of the paper when printing, the measurement method based on such a standard is not suitable. Summary of the invention

[0015] An object of the present invention is to provide a method of obtaining a paper expansion / contraction ratio with respect to a paper size under a reference environment.

[0016] The invention involved in Scheme 1 is an information processing system, which includes a processor and a sensor device, wherein the sensor device irradiates light to a target paper and detects light of an absorption band caused by the expansion and contraction movement of the HOH that passes through the paper, and the processor performs the following processing: based on the detection result of the sensor device, obtaining absorption information representing the amount of absorption of the absorption band by the paper; and using a prediction model that predicts the expansion and contraction rate of the paper based on the absorption information of the absorption band in the paper, obtaining the expansion and contraction rate of the paper corresponding to the obtained absorption information.

[0017] According to the information processing system of claim 1, in the invention according to claim 2, the absorption band is a wavelength band near 1450 nm or near 2900 nm.

[0018] According to the information processing system of claim 1, in the invention according to claim 3, the processor enlarges or reduces the image printed on the paper according to the calculated expansion / contraction ratio.

[0019] According to the information processing system described in Scheme 3, in the invention involved in Scheme 4, the processor calculates the scaling ratio of the image printed on the front side of the paper and the scaling ratio of the image printed on the back side of the paper based on the scaling ratio, and enlarges or reduces the image printed on the front side of the paper and the image printed on the back side of the paper at the scaling ratio calculated for each image, and the scaling ratio of the image printed on the back side of the paper is specified so that the size of the image printed on the back side after the image on the front side of the paper is fixed is the same as the size of the image on the front side.

[0020] The invention involved in Scheme 5 is a storage medium storing a program for causing a computer to execute the following processing: obtaining a detection result of a sensor device that irradiates light to a target paper and detects light of an absorption band caused by the expansion and contraction movement of the HOH that passes through the paper, and obtaining absorption information representing the amount of absorption of the absorption band by the paper based on the obtained detection result; and using a prediction model that predicts the expansion and contraction rate of the paper based on the absorption information of the absorption band in the paper, obtaining the expansion and contraction rate of the paper corresponding to the obtained absorption information.

[0021] The invention involved in Scheme 6 is an information processing method, which includes the following steps: obtaining a detection result of a sensor device that irradiates light to a target paper and detects light of an absorption band caused by the expansion and contraction movement of the HOH that passes through the paper, and obtaining absorption information representing the amount of absorption of the absorption band by the paper based on the obtained detection result; and using a prediction model that predicts the expansion and contraction rate of the paper based on the absorption information of the absorption band in the paper to obtain the expansion and contraction rate of the paper corresponding to the obtained absorption information.

[0022] Effects of the Invention

[0023] According to the first, second, fifth and sixth aspects of the present invention, it is possible to provide a method for obtaining the expansion / contraction ratio of paper with respect to the paper size under a reference environment.

[0024] According to the third aspect of the present invention, it is possible to print an image having a size corresponding to the current expansion and contraction state of the paper.

[0025] According to the fourth aspect of the present invention, the sizes of the images on the front and back sides of a sheet of paper can be made equal during double-sided printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Embodiments of the present invention will be described in detail with reference to the following drawings.

[0027] Figure 1 is a diagram illustrating the structure of a system for building a prediction model;

[0028] Figure 2 is a diagram illustrating steps of a process for building a prediction model;

[0029] Figure 3 It is a graph showing the detection value of the 1450 nm band and the measurement results of the expansion and contraction ratio;

[0030] Figure 4 It is a graph showing the detection value of the 1940 nm band and the measurement results of the expansion and contraction ratio;

[0031] Figure 5 is a graph showing the correlation between the expansion and contraction ratio predicted by the regression equation obtained using the 1450 nm band and the measured expansion and contraction ratio;

[0032] Figure 6 is a graph showing the correlation between the expansion and contraction ratio predicted by the regression equation obtained using the 1940 nm band and the actually measured expansion and contraction ratio;

[0033] Figure 7 is a diagram illustrating a configuration of an image forming apparatus using a prediction model;

[0034] Figure 8 The figure is a diagram illustrating the content of the scaling information applied when printing on one side or the front side of double-sided printing;

[0035] Fig. 9 is a diagram illustrating the content of scaling information applied when printing on the back side of double-sided printing;

[0036] Fig.10 is a diagram illustrating processing steps performed by an image forming apparatus;

[0037] Fig.11 This is a diagram illustrating the hardware configuration of a computer.

[0038] Explanation of symbols

[0039] 10-medium sensor, 12-light source, 14-photodetector, 20-expansion and contraction testing device, 30-information processing system for constructing prediction model, 40-information processing system, 42-prediction model, 44-expansion and contraction ratio prediction unit, 46-image correction unit, 48-scaling ratio information storage unit, 50-printing mechanism, 200-image forming device. DETAILED DESCRIPTION

[0040] <Principle of expansion / contraction ratio prediction>

[0041] A method for predicting the expansion / contraction ratio of paper in a mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described.

[0042] Water has the property of absorbing infrared rays, especially near wavelengths of 1940nm (nanometers), 2900nm, and 1450nm. The absorption band near the wavelength of 1940nm is caused by the stretching and angular vibration of OH (hydroxyl). The absorption band near the wavelength of 2900nm is caused by the stretching vibration of HOH (water molecules). The wavelength near 1450nm is half the wavelength of the 2900nm band, and water also absorbs infrared rays near this band very well.

[0043] Since the amount of infrared absorption is correlated with the amount of water contained in the object, the amount of water can be measured by accurately measuring the amount of infrared absorption.

[0044] Paper is mainly composed of cellulose fibers. Cellulose has OH groups. When the paper does not contain water, the OH groups of adjacent cellulose fibers are directly bonded to each other through hydrogen bonds. When the paper contains water, the cellulose fibers are slowly bonded to each other through hydrogen bonds via HOH (water molecules).

[0045] When the humidity rises and the amount of water contained in the paper increases, the paper expands, and conversely, when the amount of water contained in the paper decreases, the paper contracts. Therefore, the expansion and contraction rate of the paper corresponding to the humidity can be measured or predicted based on the amount of infrared absorption.

[0046] When measuring or predicting the moisture content of paper or the shrinkage rate of paper by infrared spectroscopy, it is believed that the accuracy is higher when using the 1450nm band or the 2900nm band than the 1940nm band. This is believed to be because the infrared rays of the 1940nm band are also absorbed by the OH groups of the cellulose fibers constituting the paper, while the infrared rays of the 1450nm band or the 2900nm band are not easily absorbed by the cellulose fibers and are mostly absorbed by the moisture contained in the paper.

[0047] In this embodiment, the 1450nm band or the 2900nm band, or both, is referred to as the wavelength band of interest. That is, the absorption band caused by the expansion and contraction movement of the HOH is referred to as the wavelength band of interest. Then, the absorption amount of infrared light in the wavelength band of interest relative to the paper is measured, and the expansion and contraction rate of the paper is calculated based on the measured absorption amount.

[0048] Here, the expansion ratio mentioned in this embodiment is a value indicating the extent to which the paper size in the current environment expands and contracts relative to the paper size when the environment is in a reference state. The reference state is a combination of a specific temperature (e.g., 20 degrees Celsius) and a humidity (e.g., 25%). The paper size when the environment is in the reference state (referred to as the reference size) is the paper size when equilibrium is reached in the reference state. The expansion ratio can be calculated separately for the longitudinal and transverse directions of the paper, or it can be a single value based on the two (e.g., the average of the two). When the paper size in the reference state is set to L0 and the paper size in the current state is set to L1, the expansion ratio is calculated by the following formula.

[0049] Stretch ratio = 100 × (L1-L0) / L0

[0050] In this example, the expansion and contraction rate is expressed as a percentage. If the expansion and contraction rate of the paper is +1%, the paper is expanded by 1% relative to the reference size, and if it is -1%, the paper is contracted by 1%.

[0051] The paper size changes according to the change of the moisture content of the paper. The more moisture the paper contains, the more the paper stretches. In addition, the moisture content of the paper has a strong correlation with the absorption of infrared light in the wavelength band of interest. Therefore, in this embodiment, a prediction model is constructed to predict or estimate the expansion and contraction rate of the paper based on the absorption of infrared light in the wavelength band of interest that passes through the paper.

[0052] <System structure for building prediction models>

[0053] Figure 1 2 shows an example of a system for estimating the expansion and contraction rate of paper based on the absorption of infrared rays in a wavelength band of interest. The system includes a media sensor 10, an expansion and contraction test device 20, and an information processing system 30 for constructing a prediction model.

[0054] The media sensor 10 is a device for detecting one or more characteristics of paper. The characteristics detected by the media sensor 10 include the absorption amount of light in a wavelength band of interest (i.e., infrared rays in this case). In order to detect the absorption amount, the media sensor 10 includes: a light source 12 that projects light in a wavelength band including the wavelength band of interest (e.g., infrared rays) onto the paper; and a photodetector 14 that detects light emitted from the light source 12 and transmitted through the paper. The photodetector 14 has a function of at least extracting and detecting light in the wavelength band of interest. In addition, the media sensor 10 may also have a function of detecting one or more characteristics other than the absorption amount of light in the wavelength band of interest, such as the thickness of the paper, the smoothness of the surface, the basis weight, etc. The media sensor 10 has one or more sensors corresponding to the one or more characteristics to be detected.

[0055] The media sensor 10 is incorporated into an image forming device such as a printer or a multifunction machine (i.e., a multifunctional device having the functions of a printer, a scanner, a copier, etc.) to detect the characteristics of paper used in the device. The image forming device controls the printing process according to the detection result of the media sensor 10. Figure 1 The media sensor 10 included in the system is of the same model as the media sensor mounted in the image forming apparatus that utilizes the prediction model that the system intends to construct.

[0056] The expansion and contraction test device 20 is the same device as the device for measuring the expansion and contraction rate or the expansion and contraction degree in accordance with the standards such as JAPAN TAPPI No. 28 mentioned above. The expansion and contraction test device 20 has a sealed measurement chamber that can adjust the humidity to multiple humidity levels, and has a mechanism for measuring the size of the paper of the test object placed in the measurement chamber (for example, the length in the vertical direction) or the change in the size of the paper in the current state relative to the reference size of the paper (hereinafter collectively referred to as the size, etc.). The media sensor 10 is placed in the measurement chamber so as to be able to measure the absorption amount of light in the wavelength band of interest of the paper placed in the measurement chamber.

[0057] The information processing system 30 inputs the absorption amount of the wavelength band of interest detected by the media sensor 10 and the paper size measured by the expansion test device 20. The information processing system 30 obtains the expansion rate relative to the reference size based on the input size, etc., and stores the input absorption amount and its expansion rate pair. The information processing system 30 constructs a prediction model based on a collection of absorption amount and expansion rate pairs measured at each stage when the humidity in the measurement room is changed in stages.

[0058] Figure 2, the steps of constructing the prediction model based on the system are illustrated in FIG. In this step, after the operator sets the paper in the measuring room of the telescopic test device 20, the operator operates the telescopic test device 20 to adjust the humidity in the measuring room to the initial humidity specified in the plan (S10). The plan specifies a rule for increasing the humidity in stages, for example, a rule for increasing the humidity in stages by 5% from 25% to 80%. After adjusting the humidity in the measuring room to the specified humidity, the operator waits for a sufficient time (the time is known) for the paper to reach equilibrium with respect to the humidity (S12). After S12, the operator reads the value of the paper size and the like displayed on the display unit of the telescopic test device 20, and inputs the value to the information processing system 30 (S14). In addition, when the display unit of the telescopic test device 20 displays the change amount of the paper size in the current state relative to the reference size of the paper as the paper size and the like, before S10, the paper set in the measuring room is balanced to the reference state, and the paper size at equilibrium is measured and input to the information processing system 30. Furthermore, if the planned initial humidity is used as the reference state, when the paper reaches the initial humidity, the paper size (for example, the length itself) at that time may be measured in S14 and input to the information processing system 30 .

[0059] Next, the operator causes the medium sensor 10 to measure the absorption amount of the 1450nm band, reads the value of the measurement result, and inputs it to the information processing system 30 (S16). In this example, the 1450nm band is used as the wavelength band of interest. The 1450nm band is a wavelength band of a predetermined width centered on the wavelength 1450nm. For example, a wavelength band with a wavelength within a range of ±3% relative to 1450nm can be set as the 1450nm band. In addition, a wavelength band with a wavelength within a range of ±5% relative to 1450nm can be set as the 1450nm band. 3% or 5% representing the width of the wavelength band is only an example.

[0060] At this time, the media sensor 10 projects light including a wavelength band of 1450 nm from the light source 12 onto the paper, and the photodetector 14 extracts the light of 1450 nm from the light transmitted through the paper and measures its intensity. The media sensor 10 calculates and outputs the absorption amount of 1450 nm based on the intensity measured by the photodetector 14.

[0061] The information processing system 30 calculates the expansion / contraction ratio of the paper based on the input paper size and other values, and stores the obtained expansion / contraction ratio in association with the absorption amount input in S16 ( S18 ).

[0062] Next, the operator confirms whether the measurement of all humidities specified in the plan is completed (S20). If not, the process returns to S10, adjusts the humidity in the measurement room to the next humidity, and repeats the process after S12. In S20, when it is determined that the measurement of all humidities in the plan is completed, the operator instructs the information processing system 30 to execute the construction of a prediction model based on the information of the pair groups of expansion and contraction rate and absorption amount at each humidity stored so far. The information processing system 30 executes the prediction model construction program (S22).

[0063] This program, for example, performs regression analysis on pairs of the expansion / contraction ratio and the absorption amount at each humidity, thereby obtaining a regression equation for obtaining the expansion / contraction ratio from the absorption amount.

[0064] In the above description, the operator manages the steps of the operation required to construct the prediction model, but part or all of the steps may be managed by the information processing system 30. That is, for example, the information processing system 30 may manage the humidity control of the measurement room of the expansion and contraction test device 20, and the information processing system 30 may automatically obtain the measurement value from the expansion and contraction test device 20 or the medium sensor 10.

[0065] use Figure 3 , an example of regression equation is given. Figure 3 The horizontal axis of the graph shown is the spectral quantity of the 1450nm band, that is, the detection intensity, and the vertical axis is the value of the expansion and contraction rate measured in S14. The detection intensity of the 1450nm band is the intensity of the light of the 1450nm band detected by the light detector 14. The remainder obtained by subtracting the detection intensity from the intensity of the component of the 1450nm band in the light emitted by the light source 12 is the absorption amount of the paper to the 1450nm band. Since it can be assumed that the intensity of the light output from the light source 12 is constant (therefore, the intensity of the near-infrared light of the 1450nm band contained in the light is also constant), the detection intensity of the 1450nm band by the light detector 14 has a one-to-one relationship with the absorption amount of the paper to the 1450nm band. Figure 3 Each point plotted in the graph shown represents the measurement result at each humidity, that is, the pair of the detection intensity and the expansion ratio in the 1450nm band. In the following, the concept of absorption is mainly used for explanation, but as mentioned above, the absorption and the detection intensity have a one-to-one relationship, so even if the detection intensity is used instead of the absorption, the same effect can be obtained. The absorption and the detection intensity are examples of absorption information indicating the absorption of the paper in the wavelength band of interest.

[0066] When a linear simple regression analysis is performed on these point clouds, Y = -1.7508X + 2.8664 is obtained as a straight line 102 that matches these point clouds. X is the detection intensity of the 1450nm band, and Y is the stretch rate. Since each point is quite close to this straight line 102, this straight line 102 represents these point clouds with a relatively high accuracy. If the horizontal axis is set to the absorption amount of the 1450nm band, the obtained straight line will tilt to the upper right, and the slice value will also change, but even in this case, the straight line is consistent with the above. Figure 3 This straight line becomes a prediction model for predicting the expansion and contraction rate of paper based on the absorption amount (or detection intensity).

[0067] Figure 3 Focusing on the 1450nm band. As a comparative example, Figure 4 An example is shown in which attention is paid to the 1940 nm band which is also easily absorbed by water. Figure 4 Each point in the graph shown in the figure represents the pair of the detection intensity of the 1940nm band (horizontal axis) and the expansion rate of the paper (vertical axis) at each humidity, obtained by conducting the same test as above with attention to the infrared rays of the 1940nm band. When the same regression analysis is performed on these point clouds, a straight line 104, namely Y=-36.6991X+1.3118, is obtained. Figure 3 From the comparison of Figure 4 In the example of , the point clouds are quite far from the straight line 104. Therefore, the straight line 104 indicates that the accuracy of these point clouds is low.

[0068] Figure 5 The graph shown represents the Figure 3 The horizontal axis is the measured value of the stretch rate, which is obtained by the above steps. The vertical axis is the predicted value of the stretch rate, which is calculated based on the detection intensity of the 1450nm band detected by the light detector 14 (i.e. Figure 3 X), using the above prediction model (i.e. Figure 3 The expansion ratio (i.e. Figure 3 Y). Figure 5 Each point plotted in the curve graph represents a pair of measured values ​​and predicted values ​​of the expansion and contraction rate at each humidity. When these point clouds are subjected to regression analysis, a straight line 106 is obtained, that is, y = 1.0023x (x is the measured value, y is the predicted value). The plotted point clouds are all close to the straight line 106. Therefore, it can be seen that if the Figure 3 Using the straight line 102 as the prediction model, a prediction that is quite close to the measured value can be made.

[0069] In contrast, Figure 6The correlation between the measured and predicted values ​​of the stretch ratio in the example focusing on the 1940 nm band is shown in FIG. Figure 6 In the example of , when the point cloud is subjected to regression analysis, a straight line 108 is obtained, i.e., y = 0.9697x. Figure 6 In the example of , it can be seen that many points are far away from the straight line 108, and a high-precision prediction value cannot be obtained using the straight line 108.

[0070] As explained above, through Figure 1 The system can obtain a prediction model that can predict the expansion and contraction rate of paper with high accuracy based on the absorption in the 1450nm band.

[0071] In the above example, the information processing system 30 obtains a linear regression equation as a prediction model by performing regression analysis, but this is only an example. As another example, the information processing system 30 may also construct a prediction model by, for example, a neural network. In this case, the information processing system 30 inputs the absorption amount at each humidity measured in the experiment into the neural network, and gives the measured value of the expansion rate at each humidity as teacher data, thereby training the neural network to predict the expansion rate based on the absorption amount.

[0072] For each type of paper used in the image forming apparatus, use Figure 1 The system constructs a prediction model. The type of paper is represented by a combination of paper type such as uncoated paper (high-quality paper, etc.), coated paper, and basis weight. The basis weight corresponds to the thickness of the paper.

[0073] <Image forming device using prediction model>

[0074] Next, refer to Figure 7 , an example of an image forming device using a prediction model constructed in this way is described.

[0075] Figure 7 The image forming apparatus 200 shown is a device such as a printer or a multifunction peripheral, and includes a printing mechanism 50 for printing an image on a sheet of paper. The image forming apparatus 200 also includes a media sensor 10 and an information processing system 40 .

[0076] The media sensor 10 is connected to Figure 1 The device is the same model as the media sensor 10 shown in the system. Figure 7 In the example of FIG. 5 , the media sensor 10 also has a function of detecting light in a wavelength band of interest (e.g., 1450 nm band) transmitted through the paper, and obtaining and outputting the amount of light absorbed by the paper (or the detection intensity). The media sensor 10 is disposed at any position on the paper transport path in the printing mechanism 50 so as to transmit light to the transported paper and detect the light transmitted through the paper.

[0077] Although this is only one example, Figure 7 In the example, the following control is performed, that is, the expansion and contraction rate of the paper is predicted based on the measurement of the media sensor 10, and the image printed on the paper is enlarged or reduced based on the expansion and contraction rate. Therefore, the media sensor 10 is arranged at a position where the paper before the printed image can be measured. For example, in the case of a printing mechanism 50 using an electronic photography method, the media sensor 10 is arranged at an arbitrary position in the paper conveying path from the paper feed section to the photosensitive body. In addition, in the case of a printing mechanism 50 with a double-sided printing function, by providing a media sensor 10 on the conveying path immediately in front of the photosensitive body through which the paper passes regardless of whether the front side is printed or the back side is printed, the same media sensor 10 can be used to measure the paper before the front side is printed and before the back side is printed.

[0078] The information processing system 40 is a computer that performs information processing for realizing the functions of the image forming apparatus 200. The information processing system 40 controls various components in the image forming apparatus 200, such as the medium sensor 10 or the printing mechanism 50, and other units not shown in the figure. In addition, the information processing system 40 also performs the following processing, that is, predicting the expansion and contraction rate of paper and controlling the image forming apparatus 200 based on the prediction result. Here, as an example of such control, an example of controlling the size of an image printed on paper based on the prediction result of the expansion and contraction rate is described. For this control, the information processing system 40 includes a prediction model 42, an expansion and contraction rate prediction unit 44, an image correction unit 46, and a scaling information storage unit 48 as functional modules.

[0079] The prediction model 42 is a prediction model 42 constructed by the prediction model construction information processing system 30. The expansion / contraction ratio prediction unit 44 predicts the expansion / contraction ratio of the paper using the prediction model 42 based on the absorption amount input from the medium sensor 10. The image correction unit 46 corrects the image printed on the paper based on the expansion / contraction ratio predicted by the expansion / contraction ratio prediction unit 44. In this correction, the image is enlarged or reduced based on the expansion / contraction ratio information stored in the expansion / contraction ratio information storage unit 48. The image subjected to such correction is supplied to the printing mechanism 50 and printed on the paper.

[0080] Figure 8 and Fig. 9 An example of the scaling ratio information stored in the scaling ratio information storage unit 58 is shown in FIG. Figure 8 This is an example of the scaling information used when printing on one side or the front side of two sides. Fig. 9This is an example of the scaling factor information used when printing on the back side during double-sided printing. These examples are examples of the case where the media sensor 10 measures the paper before printing the image on the front side of the paper, and the scaling factors of the images printed on the front side and the back side of the double-sided printing of the paper are calculated based on the measurement results. That is, in this example, the absorption amount of the wavelength band of interest of the paper is measured before printing on the front side, and the scaling factors of the front side image and the back side image are calculated using the expansion and contraction factors of the paper at the time of the measurement calculated based on the absorption amount.

[0081] Figure 8 and Fig. 9 The scaling information shown is in the form of a table, and is information about a type of paper called uncoated paper. Each row of the table represents an interval of the expansion and contraction rate of the paper, and each column represents a basis weight band. In the example shown in the figure, the expansion and contraction rate is divided into 7 intervals from the interval below 0.1% to the interval above 1.0%. The basis weight band is the interval of the basis weight of the paper, and is represented by a group of the lower limit and upper limit of the basis weight of each interval, but in the figure to avoid complexity, it is represented by a name representing the thickness of the paper, such as "thin paper", "ordinary paper", "medium-thick paper", and "thick paper". The conveyor belt temperature shown in the row directly below the basis weight band is the temperature of the fixing conveyor belt that fixes the printed image on the paper, and the conveyor belt temperature is automatically determined according to the type of paper. In the figure, the conveyor belt temperature during the fixing process of ordinary paper is used as a reference, and the positive and negative temperature differences relative to this reference are represented as the conveyor belt temperature of each basis weight band.

[0082] exist Figure 8 and Fig. 9 In the cell where each row and column intersect, the scaling ratio of the image corresponding to the combination of the stretch ratio interval and the base tape is registered. Regarding the scaling ratio, 100% represents the original image itself, neither enlarged nor reduced, a value greater than 100% represents enlargement, and a value less than 100% represents reduction. For example, a scaling ratio of 100.5% applicable when the stretch ratio is 1.0% or more and the base tape is thin paper means that the original image is enlarged to 100.5% (i.e., 0.5% larger than the original size).

[0083] Figure 8 and Fig. 9 The example is only an example, but the lowest humidity state is assumed as the reference state, and the size of the image printed on the front of the paper in the reference state is taken as the reference, that is, 100%. Since the humidity in other states is higher than the humidity in the reference state, the paper will stretch when printing on the front side, and the expansion rate is higher than 100%. In this embodiment, in the front side printing of single-sided printing or double-sided printing, the size of the image printed on the paper is enlarged or reduced depending on how much the paper expands from the reference state during printing. Therefore, in Figure 8 In the example, the larger the scaling ratio is, the larger the image magnification is.

[0084] Therefore, when the same image is printed on paper of the same type, basis weight and size (for example, paper of the same manufacturing batch), the images on the respective papers become the same size when they are balanced to the same environmental conditions after printing, even if the environmental conditions (for example, humidity) are different during printing. That is, the size of the printed image is suppressed from being deviated due to the difference in environmental conditions during printing.

[0085] In addition, if the average humidity is used as the reference state, the humidity of the environment during printing may be lower than the reference state. In this case, the paper shrinks compared to the reference state. Figure 8 and Fig. 9 In the illustrated scaling ratio information, a section including a negative value is also set as a section of the predicted value of the scaling ratio.

[0086] Fig. 9 The zoom ratio of each cell in the zoom ratio information for the back side shown in the example becomes Figure 8 The zoom ratio of the corresponding cell in the zoom ratio information of the front side is shown as a small value. This reflects the following situation: due to the heating in the fixing part (such as the fixing conveyor belt) when printing on the front side, the moisture of the paper evaporates and the paper shrinks. The thicker the paper is, the easier it is to shrink, so the reduction in the zoom ratio is greater when compared with the front side. By using Fig. 9 The illustrated scaling information can make the size of the image printed on the back of the paper the same as the size of the image printed on the front of the paper, thereby enabling size adjustment when predicting (registering) the front and back.

[0087] Figure 8 and Fig. 9 The zoom ratio information exemplified may be created by conducting experiments or the like when developing the image forming apparatus.

[0088] In addition, in the case of an apparatus configuration in which the absorption amount of the wavelength band of interest is measured for the paper even at a position after printing on the front side and before printing on the back side, the value of the scaling factor of each cell in the scaling factor information for the back side is greater than Fig. 9 The value shown is large because when the measurement is performed after printing on the front side and before printing on the back side, the paper is measured in a state of shrinkage due to heating and fixing of the front side image, and the process of further shrinkage of the paper (such as fixing) is not included after the measurement until the printing of the back side image.

[0089] Next, refer to Fig.10 , an example of the processing steps executed by the information processing system 40 is described. For example, each time a sheet of paper is taken out from the paper supply unit and the paper is printed, the information processing system 40 executes Fig.10 The steps illustrated.

[0090] In this step, first, the expansion / contraction rate prediction unit 44 of the information processing system 40 obtains the basis weight of the paper to be printed and the information of the fixing temperature suitable for the paper (S30). The information about the basis weight should be registered in the information processing system 40 by the operator, for example, when a paper bundle is set in the paper feeding unit, so it is sufficient to obtain this information. Alternatively, the basis weight of the paper can be measured by the medium sensor 10. In addition, since the information of the fixing temperature corresponding to the basis weight of the paper is pre-registered in the information processing system 40, the information processing system 40 can grasp the fixing temperature based on this information.

[0091] Next, the expansion ratio prediction unit 44 of the information processing system 40 obtains the value of the absorption amount in the wavelength band of interest from the medium sensor 10 that measures the paper (S32), and obtains the expansion ratio of the paper corresponding to the absorption amount using the prediction model 42 (S34). For example, when the prediction model 42 is a regression equation that represents the relationship between the absorption amount and the expansion ratio, the expansion ratio prediction unit 44 obtains the expansion ratio by substituting the absorption amount into the regression equation.

[0092] Next, the image correction unit 46 of the information processing system 40 reads the scaling ratios of the front and back sides corresponding to the combination of the basis weight acquired in S30 and the expansion ratio calculated in S34 from the scaling ratio information storage unit 48 (S36). The image correction unit 46 enlarges or reduces the image printed on the front side and the image printed on the back side of the paper at the scaling ratios calculated in S36, and supplies the enlarged or reduced images to the printing mechanism 50 (S38). The printing mechanism 50 prints the image supplied from the image correction unit 46 on the front side and the back side of the paper.

[0093] In the above, an example has been described in which the size of the image printed on the paper is controlled using the expansion / contraction ratio of the paper predicted by the expansion / contraction ratio prediction unit 44 .

[0094] exist Fig.10 In the example of , the predicted value of the expansion ratio of the paper obtained based on the measurement result before printing the front side of the paper is used to control not only the expansion ratio of the image on the front side, but also the expansion ratio of the image on the back side. However, this is only one example. As another example, after fixing the image printed on the front side of the paper and before printing the back side, the absorption amount of the paper to the wavelength band of interest can be measured, the expansion ratio can be predicted based on the absorption amount, and the expansion ratio of the back side image can be controlled based on the predicted expansion ratio.

[0095] The embodiments of the present invention have been described above, but these embodiments are only exemplary. Various modifications can be made within the scope of the technical concept of the present invention. Figure 7In the example of FIG. 4 , the expansion / contraction ratio prediction unit 44 is located in the image forming apparatus 200, but the expansion / contraction ratio prediction unit 44 may be located outside the image forming apparatus 200. For example, a server providing the function of the expansion / contraction ratio prediction unit 44 exists on the network, and the information processing system 40 of the image forming apparatus 200 may send the measurement result of the medium sensor 10 to the server and obtain the predicted value of the expansion / contraction ratio from the server.

[0096] Furthermore, in the above example, the media sensor 10 obtains the absorption amount of the wavelength band of interest, but as another example, for example, the media sensor 10 may detect the transmitted light of the wavelength band of interest and output its intensity, and the information processing system 40 may obtain the absorption amount of the wavelength band of interest by the paper based on the intensity. That is, the processor that performs the process of obtaining the absorption amount based on the intensity of the transmitted light of the wavelength band of interest may be a processor in the media sensor 10 or a processor in the information processing system 40.

[0097] The information processing systems 30 and 40 described above are configured using, for example, a general-purpose computer. Fig.11 As shown in the example, the computer has a controller for controlling a processor 1002, a memory (main storage device) 1004 such as a random access memory (RAM), an auxiliary storage device 1006 as a non-volatile storage device such as a flash memory or SSD (solid state drive), HDD (hard disk drive), etc., an interface with various input and output devices 1008, and a network interface 1010 for controlling connection with a network such as a local area network, etc., and a circuit structure connected via a data transmission path such as a bus 1012. The program recording the processing content of the above-mentioned embodiment is installed in the computer via a network or the like, and is stored in the auxiliary storage device 1006. The processor 1002 executes the program stored in the auxiliary storage device 1006 using the memory 1004, thereby constituting the information processing mechanism of the present embodiment. In addition, the information processing systems 30 and 40 may include an image processing processor for performing general or special purpose image processing at high speed, or a dedicated processor for neural network processing, etc.

[0098] Furthermore, the information processing systems 30 and 40 may each be composed of a single computer or a plurality of computers. For example, a part of the functions of the information processing system 40 may be provided on another computer outside the image forming apparatus 200 .

[0099] In the above-mentioned embodiments, the processor refers to a processor in a broad sense, including a general-purpose processor (for example, CPU: Central Processing Unit, etc.) or a dedicated processor (for example, GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0100] Furthermore, the actions of the processors in the above-mentioned embodiments may be performed not only by one processor but also by a plurality of processors in physically separate locations. Furthermore, the order of the actions of the processors is not limited to the order described in the above-mentioned embodiments but may be changed as appropriate.

[0101] (Note) (1)

[0103] An information processing system comprising a processor and a sensor device,

[0104] The sensor device irradiates light onto a target paper and detects light of an absorption band caused by the expansion and contraction movement of the HOH that passes through the paper.

[0105] The processor performs the following processing:

[0106] Based on the detection result of the sensor device, obtaining absorption information indicating the amount of absorption of the absorption band by the paper; and

[0107] Using a prediction model for predicting the expansion and contraction rate of the paper based on the absorption information of the absorption band in the paper, the expansion and contraction rate of the paper corresponding to the obtained absorption information is obtained. (2)

[0109] The information processing system according to (1), wherein:

[0110] The absorption band is a wavelength band near 1450 nm or near 2900 nm. (3)

[0112] The information processing system according to (1), wherein:

[0113] The processor enlarges or reduces the image printed on the paper according to the obtained expansion / contraction ratio. (4)

[0115] The information processing system according to (3), wherein:

[0116] The processor calculates the scaling ratio of the image printed on the front side of the paper and the scaling ratio of the image printed on the back side of the paper based on the scaling ratio, and enlarges or reduces the image printed on the front side of the paper and the image printed on the back side of the paper at the scaling ratio calculated for each image.

[0117] The scaling ratio of the image printed on the back side of the paper is specified so that the size of the image on the back side printed after the image on the front side of the paper is fixed is the same as the size of the image on the front side. (5)

[0119] A program for causing a computer to execute the following processing:

[0120] Acquire detection results of a sensor device that irradiates light to a target paper and detects light of an absorption band caused by the expansion and contraction movement of the HOH that passes through the paper, and obtain absorption information indicating the amount of absorption of the absorption band by the paper based on the acquired detection results; and

[0121] Using a prediction model for predicting the expansion and contraction rate of the paper based on the absorption information of the absorption band in the paper, the expansion and contraction rate of the paper corresponding to the obtained absorption information is obtained.

[0122] According to the information processing system described in (1), the information processing system described in (2), and the program described in (5), a method of obtaining the expansion / contraction ratio of paper with respect to the paper size under a reference environment can be provided.

[0123] According to the information processing system described in (3), it is possible to print an image having a size corresponding to the current expansion and contraction state of the paper.

[0124] According to the information processing system described in (4), the sizes of the images on the front and back sides of the paper can be made consistent during double-sided printing.

[0125] The above-mentioned embodiments of the present invention are provided for the purpose of illustration and description. In addition, the embodiments of the present invention do not fully and exhaustively include the present invention, and do not limit the present invention to the disclosed methods. Obviously, various modifications and changes are self-evident to those skilled in the art to which the present invention belongs. The present embodiment is selected and described in order to most easily understand the principles of the present invention and its application. Thus, other technicians in the art can understand the present invention through various variations optimized for specific uses assumed to be various embodiments. The scope of the present invention is defined by the above claims and their equivalents.

Claims

1. An information processing system comprising a processor and a sensor device, The sensor device irradiates light to a target paper and detects light of an absorption band caused by the expansion and contraction movement of the HOH that passes through the paper. The processor performs the following processing: Based on the detection result of the sensor device, obtaining absorption information indicating the amount of absorption of the absorption band by the paper; and Using a prediction model for predicting the expansion and contraction rate of the paper based on the absorption information of the absorption band in the paper, the expansion and contraction rate of the paper corresponding to the obtained absorption information is obtained.

2. The information processing system according to claim 1, wherein: The absorption band is a wavelength band near 1450 nm or near 2900 nm.

3. The information processing system according to claim 1, wherein: The processor enlarges or reduces the image printed on the paper according to the obtained expansion / contraction ratio.

4. The information processing system according to claim 3, wherein: The processor calculates the scaling ratio of the image printed on the front side of the paper and the scaling ratio of the image printed on the back side of the paper based on the scaling ratio, and enlarges or reduces the image printed on the front side of the paper and the image printed on the back side of the paper at the scaling ratio calculated for each image. The scaling ratio of the image printed on the back side of the paper is specified so that the size of the image on the back side printed after the image on the front side of the paper is fixed is the same as the size of the image on the front side.

5. A storage medium storing a program for causing a computer to execute the following processing: Acquire detection results of a sensor device that irradiates light to a target paper and detects light of an absorption band caused by the expansion and contraction movement of the HOH that passes through the paper, and obtain absorption information indicating the amount of absorption of the absorption band by the paper based on the acquired detection results; and Using a prediction model for predicting the expansion and contraction rate of the paper based on the absorption information of the absorption band in the paper, the expansion and contraction rate of the paper corresponding to the obtained absorption information is obtained.

6. An information processing method comprising the following steps: Acquire detection results of a sensor device that irradiates light to a target paper and detects light of an absorption band caused by the expansion and contraction movement of the HOH that passes through the paper, and obtain absorption information indicating the amount of absorption of the absorption band by the paper based on the acquired detection results; and Using a prediction model for predicting the expansion and contraction rate of the paper based on the absorption information of the absorption band in the paper, the expansion and contraction rate of the paper corresponding to the obtained absorption information is obtained.

Images