JP2006036425A - Sheet material discrimination device, heating device using this and image formation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize prevention of erroneous detection during usage for a long period of time of a sheet material discrimination device not requiring paper kind selection setting work by a user and capable of efficiently performing good heat treatment, fixing and image formation even if the paper having any surface roughness, rigidity and thickness and to provide a heating device using this and various kinds of image formation devices. <P>SOLUTION: A surface roughness discrimination characteristic correction sheet is attached to a device having a piezo-electric contact type media sensor and when the result of cumulative detection number (=cumulative paper-passing number) count of the device arrives at a predetermined number, a correction requirement signal is transmitted and correction by paper-passing of the discrimination characteristic correction sheet is promoted. Further, the correction sheet is attached to a consumption cartridge of the device and the correction is promoted at every cartridge exchange or cartridge attachment/detachment. Further, two kinds of correction sheets of low rigidity sheet and high rigidity sheet are attached in the device making discrimination of rigidity of the sheet material preferential and correction of the rigidity discrimination characteristic is realized from difference of both sheets. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet material identification device for identifying a difference in surface frictional resistance of a measured object, a difference in surface roughness and a surface material as a cause thereof, a heating device including this device, and an electrophotographic printer The present invention relates to an image forming apparatus such as a copying machine, an ink jet printer, a thermal head printer, a dot impact printer, a facsimile, or a composite device thereof.

  2. Description of the Related Art Conventionally, various image forming apparatuses are apparatuses for forming an image on a sheet-like recording material such as plain paper, postcard, cardboard, sealed letter, OHP plastic thin plate, etc. In apparatuses such as printers, copiers, and facsimile machines that use this method, a toner image is formed on a recording material by electrostatic image forming means using toner as a developer, and then the recording material is heated and heated by fixing means. The toner image is melted and fixed under pressure to form an image.

  In addition, other devices such as printers, copiers, and facsimiles using an ink jet system use ink as a developer and use a number of nozzles having minute orifices utilizing mechanical or thermal reactions. An image is formed on the recording material by image forming means for ejecting ink from the configured recording head at a high speed.

  In addition, other apparatuses such as printers, copiers, and facsimile machines using a thermal transfer method use an ink ribbon as a developer and use a thermal head to transfer ink from the ink ribbon to the recording material by means of image forming means. An image is formed.

  By the way, these devices have been improved in recent years, and devices for higher image quality and higher processing speed have been realized by various means. At the same time, cost reduction measures have been devised to reduce costs. Advancing and becoming widespread.

  However, the types of recording materials used in these image forming apparatuses vary widely, from plain paper to high-grade paper with special surface treatment for sealed letters and resin sheets for OHP. Accordingly, since it has been used all over the world, it is necessary to cope with it so that a good image can be formed on any recording material used in various places. The roughness of the recording material surface, which greatly affects the recording material, is a very important factor.

  For example, in an apparatus employing an electrophotographic system, when the surface of the recording material used is smooth (hereinafter referred to as smooth paper) or rough (hereinafter referred to as rough paper), the paper surface from the heating source in the fixing unit The heating efficiency for transferring heat to the surface differs according to the difference in thermal resistance due to the difference in surface properties, and even if the rough paper is fixed at an appropriate fixing temperature with smooth paper, it causes insufficient fixing. It is necessary to fix at a high temperature. For this reason, the current apparatus uses the temperature at which rough paper can be fixed as the standard fixing temperature, and is always fixed at an excessive temperature for smooth paper, and even for rougher paper. Since a higher fixing temperature is required, a selection mode is provided for allowing the user to change the setting of the fixing temperature when using such paper.

  FIG. 3 shows a basic configuration of a printer that employs an electrophotographic system as a specific example of these.

  That is, FIG. 3 is a cross-sectional view of a main part of a conventional printer. In the printer, the surface of the photosensitive drum 2 is uniformly charged to a predetermined polarity by the charging roller 1 and then exposed by an exposure means 3 such as a laser. Only the area where the photosensitive drum 2 is exposed is neutralized to form a latent image on the photosensitive drum 2. The latent image is developed by the toner 5 of the developing device 4 to be visualized as a toner image. That is, the toner 5 of the developing device 4 is frictionally charged with the same polarity as the charging surface of the photosensitive drum 2 between the developing blade 4a and the developing sleeve 4b, and DC and AC are developed in the developing gap portion where the photosensitive drum 2 and the developing sleeve 4b face each other. A bias is applied in a superimposed manner, and the toner 5 is selectively attached to the latent image forming portion of the photosensitive drum 2 while floating and oscillating by the action of an electric field, and then the toner 5 is transferred by the transfer roller 6 and the photosensitive drum 2. The photosensitive drum 2 is conveyed to the nip portion by rotation.

  On the other hand, the recording material 7 such as paper on which an image is recorded is fed from the recording material storage box 7a to the vertical conveying roller pair 7d by a pair of feed rollers 7c (the lower roller may be a pad), It is transported through the path of either the vertical transport roller pair 7d to the pre-transfer transport roller 7d 'or the manual feed tray 7b by the paper feed roller pair 7c to the pre-transfer transport roller 7d'. The pre-transfer conveying roller 7d 'conveys the transfer upper guide plate 9 and the lower transfer guide plate 9' to the transfer nip portion at a predetermined entry angle. Until the recording material 7 is conveyed from the pre-transfer conveying roller 7d ′ to the transfer nip portion, the recording material 7 is rubbed with various members that are in contact before the recording material 7 is conveyed to this region. Since there is a possibility that the surface of the material 7 is charged, the back surface of the recording material 7 being transported by the neutralizing brush 8 for removing such unnecessary charging that causes an image disturbance when performing electrostatic recording is provided. It is provided in contact with the side and is grounded.

  In order to electrostatically attract the toner 5 on the photosensitive drum 2 and move it to the recording material 7 side in the transfer portion, a high voltage having a polarity opposite to that of the toner 5 is applied to the transfer roller 6 on the back surface of the recording material 7. The toner 5 is electrostatically attracted to the back surface of the toner and the toner image is transferred to the recording material 7, and the back surface of the recording material 7 is charged with a polarity opposite to that of the toner 5, so that the transferred toner 5 is continuously held. The transfer charge is applied to the back surface of the recording material 7.

  Finally, the recording material 7 onto which the toner image has been transferred is conveyed to a fixing device 12 composed of a heating rotator 13 and a pressure roller 14 that forms a nip portion, and a fixing temperature preset in the nip portion is set. The toner image is fixed by being heated and pressurized while being controlled by a heater provided on the heating rotator 13 side so as to be held.

  In addition, since the deposits such as toners having different polarities remain slightly on the surface of the photosensitive drum 2 after the toner image transfer, the surface of the photosensitive drum 2 after passing through the transfer nip portion is the surface of the photosensitive drum 2 by the cleaning container 10. After the adhering matter is scraped off and cleaned by the cleaning blade 10a that is in contact with the counter, the apparatus waits for the next image formation.

  The above-described components of the charging roller, the photosensitive drum, the developing container, and the cleaning container have a relatively short replacement cycle. Therefore, a cartridge replacement type apparatus that can be replaced in units of the cartridge 11 in which these components are integrated is widely used. is doing.

  Among the above processes, a contact heating type fixing device with good thermal efficiency and safety is widely known as an image fixing method. Conventionally, a release layer is mainly formed on the surface of a metal cylindrical metal core. Then, a heat fixing roller containing a halogen heater inside the cylinder and an elastic layer made of heat-resistant rubber formed on the metal core, and a pressure roller formed by forming a pressure-side release layer on the surface are pressed. In recent years, a heat roller fixing device constructed by abutting has been used. However, as a method with higher heating efficiency, a surface of a heat resistant resin film having a low heat capacity is processed into a cylindrical shape instead of the heat fixing roller. A film heating type fixing device is used in which a fixing film on which a release layer is formed is used and a ceramic heater is brought into contact with and heated from the inside of the fixing nip portion of the film.

  This type of film heating type fixing device has higher heat transfer efficiency than the conventional heat roller method using a cylindrical metal containing a halogen heater as a fixing roller from the viewpoint of promoting energy saving in recent years, and the apparatus is also started up. Although it has been attracting attention as a fast method and has been applied to higher-speed models, it is necessary to reduce the heat capacity of the heating surface of the fixing unit in order to emphasize the rate of temperature increase. It is difficult to form an elastic layer on the heating surface, and a hard heating surface is used. For this reason, this type of fixing method has a configuration in which a difference in heating efficiency is likely to occur due to unevenness on the surface of the recording material.

  In various image forming apparatuses such as a printer using such a fixing device, as the processing speed is increased as described above, there is a problem that a difference in fixing property becomes remarkable due to a difference in paper type. The user himself / herself needs to input an appropriate fixing mode to the printer in advance according to the type of paper that the user intends to use.

  However, forcing the user to select a mode in order to switch the fixing condition each time depending on the type of paper used in this way increases the work burden on the user, and if the selection mode is wrong, fixing the print amount. However, there is a possibility that power is wasted due to excessive heating, power is wasted, image defects occur due to high temperature offset, and toner contamination of the fixing device is caused.

  Further, in a usage environment in which a single network printer is shared by a plurality of users as in recent years, a special user uses a special paper and switches the mode setting accordingly, and then the special paper is used. May be left on the device, and when used by other users who do not know that, the modes may not match and may not be properly fixed, causing the problem described above. It is high.

  Also, regarding the number of fixing modes that can be set, there are strictly different levels of actual paper smoothness, and it is impossible to set optimum conditions for each of them. The number of setting modes is limited by batch-fixing papers with smoothness in a range in the same mode. For certain papers, fixing may be performed using more power than necessary. Depending on the combination, inefficient fixing may be performed.

  On the other hand, in the apparatus employing the ink jet method, the amount of ink required differs between the case where the recording material used is smooth paper and the case of rough paper, and an image on the rough paper with an appropriate amount of ink on smooth paper. Even if it is formed, the ink permeates in the thickness direction of the paper and causes a lack of density, so it is necessary to eject more ink to the rough paper. For this reason, in the current apparatus, it is necessary for the user to perform an operation for causing the printer to recognize the paper type in advance for the paper having different surface properties.

  Also, in the apparatus adopting the thermal transfer method, the amount of power required differs between the case where the recording material used is smooth paper and the case of rough paper. However, since the thermal resistance is large, the transferability of the ink is lowered and the density is insufficient.

  As described above, in all current apparatuses, excessive temperature, ink, and power are consumed to prevent image quality deterioration due to the surface roughness of the recording material, and image quality is deteriorated. In order to prevent this, it is necessary to switch these conditions according to the surface roughness of the recording material, but at present, complicated methods used in methods and some devices that force the user to change settings In addition, only optical sensors that require signal processing have been considered, leading to a significant increase in cost.

  For this reason, several proposals have been made so far for detecting the roughness of the surface of the recording material and changing the image forming conditions according to the detection result. In addition, a detection principle capable of detecting the recording material surface roughness has been proposed. In these proposals, the contact means that contacts the surface of the recording material detects physical phenomena such as vibration and rubbing sound caused by rubbing against the surface of the recording material, and detects the difference in the detected amount as the difference in surface roughness. As a specific configuration thereof, a configuration is proposed in which a piezoelectric element is provided in the contact means and vibration is converted into an electrical signal and detected.

  However, the above proposal does not disclose in detail the specific configuration conditions necessary for a member (hereinafter referred to as a probe) that is actually brought into contact with the surface of the recording material, and a simple linear probe is located upstream in the transport direction. However, only one configuration is shown in which one end is fixed and the downstream end abuts against the oblique transport direction so as not to be opposed to the diagonal conveyance direction. It was difficult.

  For this reason, in order to dramatically improve the sheet material identification performance and make it practical with the detection method using a piezoelectric element, the author newly examined the sensor probe shape and mounting configuration, and applied the tip to the probe tip. A structure that allows the contact portion to vibrate on the transport plane in the front and rear directions in the transport direction is provided, and the tip contact portion is set at an angle that bites into the measurement surface against the transport direction, resulting in extremely high discrimination performance. As a configuration that realizes such a structure at the lowest cost without impeding paper conveyance, an S-shaped sheet metal plate bent as shown in FIGS. 4 (A) and 4 (B) is bent twice. An S-shaped surface property detection sensor 15 having a configuration in which a probe having a side surface shape is rotatably fixed to a rotation shaft so that a single sensor can detect whether paper is fed from a paper cassette or a manual feed tray. In As a result of attaching and evaluating the above sensor to the transfer upper guide 9 shown in FIG. 3 which is optimal as a position that can be detected from the front side of the paper at the downstream side in the paper conveyance direction of both paper conveyance paths, It was confirmed that very high discrimination performance can be obtained without obstructing.

  More specifically, as shown in FIG. 4A, this sensor has an S-shaped probe 15a having a piezoelectric element portion 15b formed in a flat portion, and an end on the opposite side to a probe holder 15c with a fixing screw 15d. The probe holder 15c is fixed to a probe rotation shaft 15e having an axial direction perpendicular to the transport direction and parallel to the transport plane, and the probe tip is transported around the probe rotation shaft 15e. It is pressed against the flat surface by a pressing means (not shown) with a contact pressure of about 10 to 31 g. Further, the probe rotating shaft 15e is fixed on a sensor holding plate 15g (= transfer upper guide) via a bearing 15f, and a transport flat plate 15h (= transfer lower guide plate) is provided on the paper transport path as a transport plane. It has been. FIG. 4B shows the positional relationship of these members when these components are viewed from above. The tip of the S-shaped surface property detection sensor 15 is placed at the center of the sensor holding plate 15g. A square hole is made to contact the conveyance plane, and a signal line for taking out a detection signal is soldered from the surface of the piezoelectric element portion 15b and the surface of the metal plate of the S-shaped probe 15a to the electrical component of the apparatus. The surface of the holding plate 15g is routed along the longitudinal direction.

  FIG. 5A shows the output of the sensor when the main paper actually used in the electrophotographic printer is continuously fed using the S-shaped surface property detection sensor configured as described above. The result of measuring the signal waveform is shown, the horizontal axis of the graph is the paper type, and the vertical axis is the signal voltage. In this measurement, rough paper and smooth paper are alternately arranged as the order of paper to be passed, and the measurement result is clearly detected as the rough paper signal level is classified high and the smooth paper signal level is low. ing.

  However, since the signal generated for each paper is a collective waveform of fine pulse signals with this result as it is, it is necessary to process the signal acquisition at a high speed with good timing, and the smooth signal that should originally produce a low signal is required. Even in the paper signal waveform, a high pulse signal may be generated due to unforeseen factors in some papers, but in order to recognize the detection result with high accuracy inside the device, this waveform is not appropriate. There wasn't. For this reason, as a signal processing method suitable for this sensor, the writer has devised a signal processing circuit in which an integration circuit is provided in the subsequent stage of the signal detection circuit to further appropriately perform self-discharge, and the pulse signal is obtained. As a result of the processing, a waveform as shown in FIG. 5B is obtained, and the paper type can be easily identified.

  Furthermore, as an application of this sensor, a bending structure 16 is provided in the sheet material conveyance path as shown in FIG. 4C, and a paper loop is easily formed at the contact position between the sensor and the sheet material. The height of the loop differs depending on the difference in rigidity of the sheet material, that is, if the difference in rigidity is replaced with the paper thickness assuming that the material is the same, the difference in the shape of the sheet being conveyed such as thin paper 7 ′ and thick paper 7 ″ in FIG. Resulting in a pressure difference to lift the probe tip from the bottom to the top due to the difference in the amount of loop deformation of the sheet, causing the contact pressure applied to the probe tip of the sensor to change relatively, resulting in the stiffness of the paper It is also possible to detect the difference (the higher the stiffness, the higher the signal level), and the difference in stiffness between the same material is proportional to the thickness of the sheet material, so the thickness of the sheet material can also be detected Can be realized .

  By appropriately performing signal processing using the S-shaped surface property detection sensor 15 configured and attached as described above, the surface property, rigidity, and thickness of the conveyed paper are detected at least before the fixing step. Since the fixing control can be switched after completion, the user can use the apparatus without worrying about the type of paper to be used and without causing image defects and unnecessary power consumption. It becomes possible.

  However, the above configuration showed good discrimination and paper transportability at the basic examination level. However, when this S-shaped surface property detection sensor was actually incorporated into the apparatus and a continuous paper-passing durability test was conducted, There was still an incomplete part to use. FIG. 6 shows such a problem that occurs in actual use. The above sensor is incorporated in the printer, and a continuous paper endurance test with standard paper up to 450,000 sheets is performed. It is a graph of the detection characteristic evaluation result of the sensor implemented regularly for every.

  For the detection characteristics evaluation of the sensor, ten types of paper, which is a mixture of typical rough paper and smooth paper, are selected from the main paper types used in the printer. F in the paper type identification symbol: smooth paper , R: Rough paper with uniform surface roughness, W: Rough paper with wavy modification on the paper surface, each number indicates the basis weight of each paper, and generally the basis weight is Larger paper has higher rigidity and at the same time thicker. OHT indicates an OHP sheet having a very smooth surface, and a sheet of this level is hereinafter referred to as an ultra-smooth sheet.

  As can be seen from the durability results in FIG. 6, the detection performance of this sensor is as follows: “Super-smooth sheet, smooth paper, rough paper and cardboard (basis weight is 135 g) The detection signal level difference occurs for each paper so that it can be classified into the above three types, and a threshold value is provided in each of the areas “between super-smooth sheet and smooth paper” and “between smooth paper and rough paper and cardboard”. However, when the threshold for each region is considered throughout the durability period, the threshold between “super smooth sheet and smooth paper” is always a constant threshold ( In this example, the value may be approximately 0.7v), but there is little margin in the area “between smooth paper and rough paper and cardboard”, and F105 at 50k and rough paper and cardboard at other endurance points. To the value when detected relatively low There are cases where the level is almost the same or reverse, and it is difficult to identify each area with a single threshold throughout the endurance period, and there is a risk of false detection between some papers depending on the point of use .

  In the above durability evaluation, the fluctuation of the detection signal level tends to be large for thick paper having a relatively large basis weight. However, as an application destination of the sheet material identification device, a plurality of color toner layers are used even in the same electrophotographic image forming apparatus. In the color machine that fixes toner images consisting of the above and the high-speed machine that fixes at a very high speed, the fixing roller surface of the previous fixing unit is composed of an elastic layer of heat-resistant rubber, and the sheet material surface is wrapped with a soft surface A method of increasing the heating efficiency is mainly used, and in such an apparatus, the change in fixing property due to the difference in heat capacity is more important than the difference in the roughness of the surface of the sheet material. There is a case where the reliability of the paper rigidity and the paper thickness identifying ability having a high correlation is a problem.

  The present invention has been made in view of the above-mentioned problems, and the intended process is that it does not require a user to select and set the paper type, and is satisfactory regardless of the paper having any surface roughness, rigidity and thickness. An object of the present invention is to provide a heating device and various image forming apparatuses using the sheet material identification device capable of efficiently performing heat treatment, fixing, and image formation while preventing erroneous detection during long-term use.

  In order to achieve the above object, the present invention has a sheet material conveying means for conveying a sheet material and a probe with a built-in piezoelectric element, and conveys the sheet material while bringing the probe tip into contact with the surface of the sheet material. Thus, an electric signal is generated in the piezoelectric element portion by inducing distortion due to vibration and impact having a strength corresponding to the unevenness and friction coefficient of the surface of the sheet material, and based on the difference in electric signal strength, In the sheet material identification device for identifying the type, a calibration sheet having a surface roughness necessary for calibrating the identification performance of the device and the calibration sheet are periodically passed through the device to prompt calibration. Periodic calibration guidance means is provided, and the variation in detection characteristics of the probe is corrected based on the signal level generated from the piezoelectric element portion by the calibration sheet.

  Further, the calibration sheet has at least one surface roughness equivalent to the most rough sheet among the sheets that can be passed through the apparatus, and the surface having the surface roughness is passed through the sheet. Storage means for storing the signal level Vc generated from the piezoelectric element, calculation means for calculating the ratio of Vs / Vc after detecting the signal level Vs generated by conveying the sheet material, and signal levels for various standard sheets Vss and a recording means of a threshold value Sr at a ratio obtained in advance from the magnitude relationship of the ratio Vss / Vsc of the signal level Vsc to the standard calibration sheet, and the result of classifying the result of the Vs / Vc by the Sr And correcting by performing identification of the sheet material.

  Further, the calibration sheet has a surface property on one side equivalent to the sheet having the roughest surface property among sheets that can be passed through the apparatus and is equivalent to the smoothest sheet among sheets that can be passed through the apparatus. Each signal level generated from the piezoelectric element portion with respect to both the upper and lower limits of roughness by passing each surface twice in total in one calibration. It is characterized by correcting fluctuations in the detection characteristics of the apparatus based on the above.

  The calibration sheet has the same surface roughness as the most rough sheet in the sheet that can be passed through the apparatus in the first half of one side and is the smoothest sheet that can be passed through the apparatus. The piezoelectric element portion has the same surface roughness as that of a simple sheet in the latter half of the same surface, and simultaneously detects two types of surface roughness in one calibration, with respect to both the upper and lower limits of roughness. The variation of the detection characteristic of the apparatus is corrected based on each signal level generated from the above.

  In addition, ceramic particles having hardness higher than that of the probe are dispersedly applied and fixed at least in a region having a rough surface property of the calibration sheet.

  The probe is a pressurizing unit that pressurizes the tip of the probe in a circumferential direction around a fixed axis perpendicular to the sheet material conveyance direction and parallel to the conveyance plane and in a direction opposite to the sheet material conveyance direction. An angle at which the tip abutting portion can be vibrated on the probe tip portion in the transport plane in the front and rear directions in the transport direction, and the tip contact portion bites into the measurement surface against the transport direction. By conveying the sheet material while the probe tip is in contact with the surface of the sheet material, the piezoelectric element portion is caused by vibration and impact of each strength according to the unevenness and friction coefficient of the sheet material surface. It has a sheet material identification function for generating an electric signal by inducing strain and identifying the surface property of the surface of the sheet material based on the electric signal intensity difference.

  In addition, the probe uses an S-shaped sheet metal that is bent at two locations, the first bent portion R1 and the second bent portion R2, so that the tip end portion of the metal sheet metal is S-shaped when viewed from the side in the transport direction. It is an S-shaped probe in which a piezoelectric element is formed on the flat surface between the fixed end of the S-shaped sheet metal and the first bent portion.

  Further, as the periodic calibration guiding means, there is provided a cumulative sheet material identification number counting means of the apparatus, and a periodic calibration configuration is provided in the apparatus display unit or the apparatus control host each time the result of the counting means reaches a predetermined number of times set in advance. A means for transmitting a request signal is used.

  The sheet material identification device is used as a heating device, a heat-resistant resin is used as the constituent sheet, and heat treatment means for heating the material to be heated that has passed through the sheet material identification device; and the sheet material identification device Control means for controlling the heating temperature of the heat treatment means according to the identification signal is provided.

  The sheet material identification device is used in an image forming apparatus, and an image forming unit that forms a toner image on a recording material that has passed through the sheet material identification device, and a recording material on which the toner image is formed are heated and pressurized. Fixing means for fixing the toner image on the recording material, and control means for changing a fixing temperature of the fixing means and a heating time or a heating processing interval of the recording material in accordance with an identification signal of the sheet material identification device. It is characterized by that.

  Further, the calibration sheet is attached to a consumable part cartridge having at least a toner supply container as the periodic calibration guiding means, and calibration is performed using the calibration sheet attached to a new consumable part cartridge when the consumable part cartridge is replaced. Control means for controlling the apparatus is provided so that the apparatus can be used after the operation is performed.

  Further, the calibration sheet is attached to a consumable part cartridge having at least a toner supply container as the periodic calibration guiding means, and calibration is performed with the calibration sheet attached to the consumable part cartridge when the consumable part cartridge is attached or detached. Control means for controlling the apparatus is provided so that the apparatus can be used after being performed.

  In addition, the sheet material identification device is used in an image forming apparatus, and an ink ejection type image forming unit that forms an image by ejecting ink onto a recording material that has passed through the sheet material identification device, and identification of the sheet material identification device Control means for controlling the ink discharge amount of the ink discharge type image forming means in accordance with a signal is provided.

  Further, the sheet material identification device is used in an image forming apparatus, and a thermal transfer image forming means for thermally transferring ink on an ink ribbon using a thermal head on a recording material that has passed through the sheet material identification device, and the sheet material identification Control means for controlling power supplied to the thermal head of the thermal transfer image forming means in accordance with an identification signal of the apparatus.

  In addition, the sheet material conveying means for conveying the sheet material, and a probe having a piezoelectric element built therein, the sheet material is conveyed while the tip of the probe is in contact with the surface of the sheet material. A sheet material identification device for inducing strain due to vibration and impact whose strength changes according to the frictional force with the surface of the sheet material, generating an electrical signal, and identifying the rigidity of the sheet material based on the electrical signal strength difference A rigidity calibration sheet having a reference rigidity necessary for calibrating the identification performance of the device, and periodic calibration guidance means for periodically passing the stiffness calibration sheet through the device to promote calibration, Variations in detection characteristics of the apparatus are corrected based on a signal level generated from the piezoelectric element portion by the rigidity calibration sheet.

  Further, as the rigidity calibration sheet, a high-rigidity calibration sheet having the same rigidity as the most rigid sheet among sheets that can be passed through the apparatus, and the most rigid sheet among sheets that can be passed through the apparatus. Two types of low-rigidity calibration sheets that have the same rigidity as low sheets are provided, and the two types of calibration sheets are passed twice in a single calibration. On the other hand, fluctuations in detection characteristics of the apparatus are corrected based on signal levels generated from the piezoelectric element section.

  Further, by using the sheet material identification device having the above characteristics, it is possible to prevent erroneous detection of the device when using a conventional heating device or an image forming device that uses toner, ink, or ink ribbon, and the heated material or recording. It is possible to improve the detection accuracy of the surface characteristics and rigidity of the material, and to improve the reliability when optimizing the control conditions of each device according to each surface property and rigidity.

  According to the present invention, the sheet material conveying means for conveying the sheet material and a probe having a built-in piezoelectric element are provided, and by conveying the sheet material while bringing the probe tip into contact with the surface of the sheet material, A sheet that induces an electric signal by inducing a vibration due to vibration and shock according to the unevenness of the surface of the sheet material and a friction coefficient in the piezoelectric element portion, and identifies the type of the sheet material based on the electric signal intensity difference In a material identification apparatus, a calibration sheet having a surface roughness necessary for calibrating the identification performance of the apparatus or a calibration sheet having a necessary rigidity, and periodically passing the calibration sheet through the apparatus. Periodic calibration guidance means for prompting calibration is provided so that fluctuations in detection characteristics of the probe can be corrected periodically based on the signal level generated from the piezoelectric element portion by the calibration sheet. Therefore, in various types of image forming apparatuses that form images on sheet materials, ink jet methods, and thermal transfer methods, the type of sheet material to be used is identified and the optimum image forming conditions are automatically selected for each type. Performance can be maintained for a long time.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
1A, 1B, 2A, and 2B are a cross-sectional view, a flowchart, and a corrected durability result and calibration, respectively, of the sheet material identification device according to the first exemplary embodiment of the present invention. It is sectional drawing of a sheet | seat accommodating part. In FIG. 1A, the same elements as those shown in FIG. 4A are denoted by the same reference numerals.

  In this embodiment, as shown in FIG. 1 (A), the surface of the sheet conveyance flat surface portion where the probe tip portion 15a of the S-shaped surface property detection sensor 15 contacts is roughened like rough paper on the surface. The calibration sheet 17 is conveyed, and the sensor is calibrated on the basis of the signal level detected by the sensor.

  The main dimensions of each of the above components are: a probe having a width of 4 mm, a dimension of an opening in which the probe moves up and down is 6 mm × 6 mm, a length of the flat part of the probe is 15 mm, and a thickness of 0.2 mm. The element has a size of 3 mm × 6 mm and is bonded to a position 2 mm away from the end of the first bent portion of the flat portion toward the fixed end, and the probe tip abuts against the transport surface with a pressure of 10 g. Has been.

  On the other hand, the calibration sheet is a heat-resistant resin film having an envelope size of 105 mm in width and 242 mm in length and a thickness of 100 μm, and the specific material is at least durable enough to continue to use at least one sheet of the main body of the device. In consideration of the characteristics, at least the surface uses a PET film in which powder of alumina particles having hardness higher than that of the probe is dispersed and bonded, and this sheet material is conveyed at a normal conveying speed in the direction of the arrow in the figure. The average particle size of the alumina particles applied and adhered to the sheet surface is about 10 μm so that the signal level intensity detected by the piezoelectric element due to vibration generated at the probe tip is approximately equal to or higher than the signal level of the rough paper. Adhesive so that minute irregularities with the same average surface roughness Ra = 5 μm or more as standard rough paper are formed. To have.

  FIG. 1B is a flowchart showing the control of the electrophotographic printer by the sheet material identification apparatus using the calibration sheet. First, immediately after the apparatus is turned on, the number of identification detection times (≈ the number of sheets passed) ) Does not reach the predetermined number of times (in this embodiment, set every 25,000 times), the process proceeds to the print signal waiting state as it is, and when the predetermined number of times has been reached, calibration is performed on the host side. Send a calibration sheet pass request signal, pass the calibration sheet to the printer, recognize the detected signal level as the calibration level, and if the detected signal level is too low or too high There are two types of cases, when correction is difficult and within the allowable range (this time, the standard value is set to 2.6 v, 1.0 v or less and 3.3 v or less In the former case, it is determined that the sensor is abnormal. In the former case, it is determined that the sensor is abnormal, the sensor failure is notified to the host, the sensor is requested to be replaced, and the host is determined to replace it. If the operation of the device is terminated and it is determined that it will continue to be used without being replaced, control related to image formation, such as conventional standard fixing control, which does not identify the sheet material, is performed. Execute. On the other hand, in the latter case, the calibration level Vc and the cumulative number of calibrations at that time are stored in the CPU, and after receiving the print signal, the sheet feeding is started, and the sheet material is conveyed to the detection unit. When the sensor detects, the value Vs of the detection signal level for the sheet and Vs / Vc, which is the ratio of the calibration level Vc, are calculated and basically obtained in advance using a calibration sheet of the same specification. Correspondence table of standard calibration level Vsc and signal level Vss ratio Vss / Vsc for various standard sheets representing each paper type, that is, a table of each paper type judgment level normalized by the signal level of the calibration sheet. Refer to the paper type of the paper used by comparing the calculation results of Vs / Vc. Identified on the basis of the ratio of the signals, to the effective selected by the image forming the paper type to corresponding optimum image forming conditions (here mainly fixing temperature and speed control condition).

  FIG. 2 shows the result of evaluating how the detection signal level of each paper type normalized by the detection signal level of the calibration sheet thus varies during the endurance of passing 450,000 sheets. As you can see, although there are still some fluctuations, the entire paper type can be classified into three types: “super smooth sheet, smooth paper, rough paper, and cardboard”. In this case, it is possible to classify the identification areas between the ultra-smooth sheet and the smooth paper and between the smooth paper and the rough paper and the thick paper with one threshold value (ratio 0.3 and 0.6), respectively, as in the conventional results. In addition, it is possible to solve the problem that it becomes impossible to identify with one threshold in the region between “smooth paper, rough paper, and thick paper”.

  In the above configuration, the calibration sheet is basically one sheet and may be lost during long-term use. In this embodiment, the calibration sheet is calibrated in the manual feed tray as shown in FIG. The calibration sheet can be stored and stored in the tray whenever calibration is not performed using the manual-feed tray 7b ′ having a storage sheet storage space.

  In the above configuration, as a calibration method, the influence of variation is canceled by comparing the calibration level and the ratio of the detection signal level for each sheet with the threshold value when normalized, but the standard registered in advance The calibration level may be provided to calculate the ratio with the calibration level at the time of each calibration, and based on the result, the normal threshold level may be shifted, or the detection signal level may be shifted for correction. Needless to say.

<Embodiment 2>
7A and 7B are a cross-sectional view and a flowchart, respectively, of the sheet material identification device according to Embodiment 2 of the present invention. In FIG. 7A, the same elements as those shown in FIG.

  In this embodiment, as shown in FIG. 7 (A), the surface of the sheet conveyance flat surface portion where the probe tip portion 15a of the S-shaped surface property detection sensor 15 contacts is roughened like rough paper on the surface. A signal obtained by causing a sensor to detect each sheet surface by transporting the two-surface calibration sheet 17 ′ having both the surface and the opposite surface having the same smoothness as that of the smooth paper by transporting the back and front each time twice. The difference is that the calibration of the sensor is performed based on the level, and the main dimensions of the above constituent members and the calibration sheet are the same as those in the first embodiment.

  FIG. 7B is a flowchart showing the control of the electrophotographic printer by the sheet material identification apparatus using the two-side calibration sheet. First, immediately after the apparatus is turned on, the number of identification detection times (≈ It is determined whether the number of sheets has reached a predetermined number (in this embodiment, set every 25,000 times). If the predetermined number has not been reached, the process proceeds to a print signal waiting state. When the predetermined number of times has been reached, a calibration sheet passing request signal is transmitted to the host side, and the calibration sheet is passed through the printer side by side, and each of the rough and smooth surfaces detected at this time is detected. The rough signal level and the smooth signal level are recognized as calibration levels, and the detected signal level is corrected too low or too high. Classification is made in two cases: difficult case and acceptable range (this time, the standard value is set to 2.6v, and it is judged abnormal if 1.0v or less and 3.3v or more) In the former case, it is judged that the sensor is abnormal, the sensor side is notified of the sensor failure and the sensor is requested to be replaced. If the host side judges that the sensor should be replaced, the operation of the device is terminated and the replacement is made. If it is determined that it will continue to be used, printing related to image formation such as conventional standard fixing control that does not identify the sheet material is executed. On the other hand, in the latter case, the rough signal level Vcr and the smooth signal level Vcf at that time are stored in the CPU, and the result of calculating the difference between them is stored in the CPU as the dynamic range Dc at the time of calibration, and is initially registered in the apparatus. The ratio Rd = Do / Dc between the standard dynamic range Do obtained by calculating the difference between the standard rough signal level Vsr and the smoothed signal level Vsf is calculated, the result and the number of calibrations are stored in the CPU, and the print signal Return to wait state. Thereafter, a print signal is received and sheet feeding is started. When the sheet material is conveyed to the detection unit and detected by the sensor, the operator calculates the product of the value Vs of the detection signal level for the sheet and the Rd, and the result Vs ′. = Rd × Vs is identified from a comparison with the initially registered standard threshold, and image formation is performed by selecting optimum image formation conditions (mainly fixing temperature and speed control conditions) according to the paper type. To do.

  In this embodiment, since calibration is performed using both a rough surface and a smooth surface as described above, the discrimination accuracy for a smooth sheet can be improved as compared with calibration using only the rough surface. Even if 450,000 sheets continue to last, it becomes possible to continue to classify the entire paper type into three types: “super smooth sheet, smooth paper, rough paper and cardboard”. And the “thick paper” can be solved with a single threshold value.

<Embodiment 3>
8A, 8B, and 8C are respectively a cartridge mounting method explanatory diagram, a calibration sheet setting method explanatory diagram for an electrophotographic printer using the sheet material identification device according to the third embodiment of the present invention, And a cartridge replacement method explanatory diagram.

  In the present embodiment, as shown in FIG. 8A, the regular calibration guiding means is used by using a calibration sheet-attached cartridge 11 ′ in which a calibration sheet 17 is mounted on the upper surface of a conventional cartridge. When the printer is used for the first time, the top cover 18a of the printer is opened in the direction of the arrow, and when the cartridge 11 'with the calibration sheet is mounted, the calibration is executed from the printer body using the calibration sheet attached to the cartridge. The requested signal is notified to the printer main unit or the host, and after mounting the cartridge, the calibration sheet removed from the cartridge is set in the manual feed tray (or paper cassette) as shown in FIG. To detect Calibration level has a printer becomes unavailable configured to be stored in the body.

  FIG. 8C shows a state where the printer is used to replace the cartridge when the toner in the cartridge runs out. Then, the used cartridge is removed from the printer body, and a new cartridge with a calibration sheet is newly installed. In this case, a signal for requesting execution of calibration is again notified from the printer body using the calibration sheet attached to the cartridge to the printer body display unit or the host side. The printer cannot be used until the calibration sheet removed from the cartridge is set in a manual feed tray (or a paper cassette) as shown in FIG.

  In this embodiment, as described above, the calibration sheet is attached to the cartridge (it is not always necessary to be integrated, and at least it should be included), so that calibration is performed every time the cartridge is replaced from the initial mounting of the cartridge. By making it mandatory to execute the calibration, it is possible to guide calibration periodically with the cartridge life as a predetermined period. In this embodiment, the cartridge life is set to 10,000 sheets.

  Further, since the calibration sheet can be used while being periodically replaced with a new one by such setting, the calibration sheet according to the present embodiment needs to have durability until the lifetime of the main body as in the first embodiment. However, it is possible to use an inexpensive sheet that is simply obtained by processing a concavo-convex pattern similar to rough paper on the surface of a PET film.

  In the above example, the calibration cycle is defined as the cartridge life. However, it is not always necessary to limit this to the life of the cartridge. In particular, if a jam occurs during use, there is a possibility that the setting conditions of the sensor may be slightly shifted due to the jammed paper. Therefore, every time the cartridge is removed from the printer due to some reason such as jamming, including when the cartridge is replaced, a calibration request signal is sent to the printer and the calibration sheet attached to the cartridge (in this case, the calibration sheet) It is also possible to realize calibration with higher reliability by performing calibration in such a manner that the sheet is not disposable but must be returned to the original cartridge after use).

<Embodiment 4>
FIGS. 9A and 9B are a cross-sectional view and a cross-sectional view of an ink jet printer, respectively, of a sheet material identification device showing Embodiment 4 of the present invention. In FIG. 1A, the same elements as those shown in FIG. 4A are denoted by the same reference numerals.

  In the present embodiment, as shown in FIG. 9A, the surface of the front half of the sheet is roughened on the surface of the front half of the sheet on the flat surface of the sheet conveying surface where the probe tip 15a of the S-shaped surface property detection sensor 15 contacts. Using a composite calibration sheet 19 having a processed surface and a surface of the latter half of the sheet having a smoothness similar to that of smooth paper on one side, the rough surface and the smooth surface are transported once. The calibration level for the surface can be detected at the same time, and the main dimensions of the other constituent members and the calibration sheet are the same as those in the first embodiment.

  In the present embodiment, the discriminability that can cope with a wide range of surface roughness is realized by performing calibration for both the rough surface and the smooth surface in the same manner as in the second embodiment with a single calibration without the user's trouble. Although it is possible, it is not suitable for evaluating the performance of detecting the rigidity of the sheet material because of its configuration, and is suitable for an ink jet printer whose image forming conditions are relatively independent of the rigidity of the sheet material. It is used for.

  FIG. 9B is a cross-sectional view of an ink jet type image forming apparatus using the above calibration sheet, and shows the configuration of an ink jet printer 20 with a paper type detection function incorporating an S-shaped surface property detection sensor. is there.

  In this cross-sectional structure, the apparatus includes a paper feed tray 21, an ink jet paper feed roller 22, a paper guide 23, a pinch roller pair 24, a recording head 25, a platen 26, a paper discharge roller pair 27, and the like. In the embodiment, the calibration sheet 19 is used as the sensor calibration means, the S-shaped surface property detection sensor 15 is set between the paper feed roller 22 and the pinch roller pair 24, and the calibration sheet 19 is fed. The tray 21 is set with the rough side on the front end.

  The calibration method of the ink jet printer using this calibration sheet is basically the same as in the second embodiment. The difference is that the detection of the rough surface level is completed in the first half of one sheet, and the latter half. Thus, it is necessary to take in the data fetching timing to finish the detection of the smooth surface level and store each level. At this time, when an image is formed by a normal ink jet printer, the sheet material is stepped every time the recording head is sub-scanned in a direction perpendicular to the sheet passing direction by a pair of pinch rollers. At the time of calibration, at least calibration is performed. Since the calibration sheet needs to be transported at a constant speed during the period from when the leading edge of the sheet passes through the S-shaped surface property detection sensor until the trailing edge has passed, the pinch roller pair and the discharge roller at the time of calibration are discharged. The paper roller pair is controlled so as to continuously convey the sheet at a constant speed.

  Thus, based on the signal level detected by the calibration sheet, by correcting the fluctuation of the signal level during durability according to the same flowchart as in the second embodiment, the paper type of the used paper is identified, Image formation can be executed by selecting optimum image formation conditions (mainly ink discharge amount here) according to the paper type, and there are a plurality of paper surface roughness, thickness and material differences. The ink discharge amount can be optimized according to the conditions, and the best image quality according to the characteristics of the paper can be stably obtained for a long time.

<Embodiment 5>
FIGS. 10A, 10B, and 10C are cross-sectional views of a thermal head type image forming apparatus showing a fifth embodiment of the present invention, a probe tip push-up type bending structure operation explanatory diagram, and a calibration sheet passing paper description. FIG.

  In the present embodiment, an example of calibration in a thermal head printer having an S-shaped surface property detection sensor using the same calibration sheet 17 as in Example 1 as a calibration sheet is shown.

  As shown in FIG. 10A, the thermal head type image forming apparatus according to the present invention includes an ink ribbon 31, a pair of ink ribbon transport rollers 29, a thermal head 30, a head counter plate / paper transport guide 32, and the like. Usually, after receiving the print signal, the paper 7 is conveyed to the nip portion between the head opposing plate / paper conveyance guide 32 and the ink ribbon conveyance roller 29 on the paper supply side by a paper feed roller and paper conveyance roller (not shown), and the ink ribbon After being sandwiched between the guide 31 and the guide 32, the ink ribbon 31 is conveyed to the head portion while being in close contact with the ink ribbon 31, and necessary power is supplied to the head portion in accordance with the print signal, and the ink on the ink ribbon 31 is supplied. After the layer 31 'is heated and melted and thermally transferred to the paper surface, an ink image 31 "is formed on the paper, and then the transport roller It is configured to be sequentially fed by the operation.

  In the present embodiment, an S-shaped surface property detection sensor is disposed at a position opposite to at least the guide 32 and the guide portion 32 before the nip portion of the ink ribbon transport roller 29 on the paper supply side. Since the image forming apparatus melts and transfers the ink ribbon ink by directly contacting the surface of the sheet material and heating it, unlike the above-described ink jet type image forming apparatus, the image quality is easily influenced by the heat capacity of the sheet material. It is also necessary to detect the rigidity (≈ heat capacity). Therefore, in order to enhance the rigidity identification performance of the sheet material identification device of the thermal head type image forming apparatus, a probe tip push-up type bending structure 16 ′ is provided in the sheet material conveyance path upstream in the sheet material conveyance direction. ing.

  By providing this structure, as shown in FIG. 10B, the sheet material is conveyed from the lower sheet feeding unit so as to push the probe tip portion upward from below, and the rigidity of the sheet material at this time Because of the difference, that is, the difference in paper thickness, the transport path of the thin paper 7 'is low and the transport path of the thick paper 7 "is high. Therefore, the pressure applied to the probe tip from the sheet surface by each sheet material changes, and the same Even with sheets having surface properties, the higher the paper thickness, the higher the signal level is generated, and the result reflecting the paper thickness difference can be obtained.

  Using the calibration sheet 17 in the apparatus configured as described above, the paper type of the used paper is identified while correcting the fluctuation of the signal level during durability according to the first embodiment and the flowchart, and the optimum according to the paper type Image forming conditions (in this case, mainly the amount of power supplied to the thermal head unit) can be selected and image formation can be executed, and the thermal head unit according to the contact thermal resistance of the paper surface and the heat capacity of the paper The amount of power supplied to the printer can be optimized, and the best image quality can be stably obtained over a long period of time with the minimum necessary temperature and power according to the characteristics of the paper.

<Embodiment 6>
FIGS. 11A, 11B, 11C, and 11D are cross-sectional views of a color fixing unit, a rigidity identification device calibration sheet, and a low-rigidity sheet passing state illustrating Embodiment 6 of the present invention. FIG. 6 is a cross-sectional view of the state explanatory diagram when a high-rigidity sheet is passed.

  In the present embodiment, a color image forming apparatus fixing device 12 ′ using an elastic fixing roller 13 ′ having a heat-resistant rubber layer on the surface of the fixing roller as shown in FIG. The present invention relates to a calibration method for a sheet material identification apparatus when applied to an electrophotographic color image forming apparatus equipped with an image forming apparatus in a sheet that can be passed through the apparatus as a calibration sheet as shown in FIG. Two types of sheets are used: a low-rigidity sheet 18a having a rigidity equivalent to the sheet having the lowest rigidity, and a high-rigidity sheet 18b having a rigidity equivalent to the sheet having the highest rigidity among the sheets that can be passed.

  In the same electrophotographic image forming apparatus, in a color machine that fixes a toner image composed of a plurality of color toner layers at the same time, the fixing roller surface of the fixing device is composed of a heat-resistant rubber elastic layer, and the surface of the sheet material is a soft surface. In such an apparatus, the change in the fixing property due to the difference in heat capacity is more important than the difference in the roughness of the surface of the sheet material. Priority is given to the reliability of the paper stiffness and the paper thickness discrimination ability, which have a high correlation with the heat capacity of the material.

  For this reason, in the present embodiment, the probe tip surface of the S-shaped surface property detection sensor is subjected to an electrolytic polishing process to reduce the friction coefficient, thereby reducing the sensitivity to the surface roughness, and the calibration sheet. As shown in FIGS. 11 (C) and 11 (D), two calibrations are prepared for the sheet material identification apparatus provided with the bending structure 16 as shown in FIGS. 11 (C) and 11 (D). By passing the sheet, it is characterized in that only the identification performance of the difference in rigidity of the sheet material in the sheet material identification apparatus is calibrated, and the low-rigidity calibration sheet is passed as shown in FIG. In this case, the loop formed by the bent structure of the sheet is lowered, the probe lifting force Fup1 at that time is also lowered, and the frictional resistance is lowered. Detection signal level of the sensor is low as. On the other hand, when a high-rigidity calibration sheet is passed as shown in FIG. 11D, the loop formed by the bent structure of the sheet becomes high, and the probe lifting force Fup2 at that time also increases and the frictional resistance increases. As a result, the detection signal level of the sensor increases.

  As described above, regarding the control of the color image forming apparatus by the sheet material identification apparatus using the two types of calibration sheets having different rigidity, the method of the second embodiment may be basically used, and detection is performed by each calibration sheet. Based on the obtained signal level, the rigidity of the used paper (≈paper thickness) is identified while correcting the fluctuation of the signal level during durability according to each flowchart, and the optimum image forming condition (approx. Here, image formation can be performed mainly by selecting fixing temperature and speed control conditions), and it is possible to optimize fixing control according to multiple conditions such as paper thickness and material differences. Therefore, the best image quality according to the characteristics of the paper can be obtained stably for a long period of time.

(A) is sectional drawing of the sheet | seat material identification device which concerns on Embodiment 1 of this invention, (B) is a flowchart figure. It is a durability evaluation result graph of the sheet | seat material identification device which concerns on Embodiment 1 of this invention. It is a sectional view of a conventional electrophotographic image forming apparatus. (A) is a paper conveyance path cross-sectional view of a conventional S-shaped surface property detection sensor, (B) is a top view, and (C) is an explanatory diagram of a paper rigidity difference detection principle. (A) is a piezoelectric element generation signal waveform diagram of the S-shaped surface property detection sensor, and (B) is an integration processing signal waveform diagram of the S-shaped surface property detection sensor. These are the durability evaluation result graphs of the conventional sheet material identification device. (A) is sectional drawing of the paper conveyance path of the S-shaped surface property detection sensor which concerns on Embodiment 2 of this invention, (B) is a flowchart figure which concerns on Embodiment 2 of this invention. (A) is an explanatory view of a cartridge mounting method according to Embodiment 3 of the present invention, (B) is an explanatory view of a calibration sheet setting method according to Embodiment 3 of the present invention, and (C) is an embodiment of the present invention. 6 is an explanatory diagram of a cartridge replacement method according to FIG. (A) is sectional drawing of the sheet | seat material identification device which shows Embodiment 4 of this invention, (B) is an inkjet printer sectional drawing which shows Embodiment 4 of this invention. (A) is a cross-sectional view of a thermal head printer according to Embodiment 5 of the present invention, (B) is an explanatory view of the probe tip push-up type bending structure operation according to Embodiment 5 of the present invention, and (C) is an illustration of the present invention. FIG. 10 is an explanatory diagram for passing a calibration sheet according to the fifth embodiment. (A) is a cross-sectional view of a color fixing device according to Embodiment 6 of the present invention, (B) is a calibration sheet for a stiffness discriminating apparatus according to Embodiment 6 of the present invention, and (C) is an embodiment of the present invention. 6 is a state explanatory diagram at the time of low-rigidity sheet passing according to FIG. 6, and (D) is a state explanatory diagram at the time of high-rigidity sheet passing according to Embodiment 6 of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Charging roller 2 Photosensitive drum 3 Exposure means 4 Developer 5 Toner 6 Transfer roller 7 Recording material 12 Fixing device 11 Cartridge 11 'Cartridge with calibration sheet 15 S-shaped surface property detection sensor 15c Probe holder 15d Fixing screw 15e Probe rotation shaft 15 g Sensor holding plate 15 h Transport flat plate 16 Bending structure 17 Calibration sheet 17 ′ Two-side calibration sheet 18 Printer body 19 Composite calibration sheet 20 Inkjet printer 25 Recording head 38 Thermal head printer 30 Thermal head 31 Ink ribbon

Claims (16)

  A sheet material conveying unit configured to convey the sheet material; and a probe having a piezoelectric element built therein, and the sheet material is conveyed while the tip of the probe is in contact with the surface of the sheet material. In the sheet material identification apparatus for inducing strain due to vibration and impact having a strength according to the unevenness and friction coefficient of the material surface to generate an electrical signal, and identifying the type of the sheet material based on the electrical signal strength difference, A calibration sheet having a surface roughness necessary for calibrating the identification performance of the apparatus, and periodic calibration guiding means for periodically passing the calibration sheet through the apparatus to promote calibration, and the calibration sheet. The sheet material identification device according to claim 1, wherein a variation in detection characteristics of the probe is corrected based on a signal level generated from the piezoelectric element portion.   2. The apparatus according to claim 1, wherein the calibration sheet has at least one surface roughness equivalent to that of the most rough sheet among sheets that can be passed through the apparatus, and the surface having the surface roughness. Storage means for storing the signal level Vc generated from the piezoelectric element by passing paper, calculation means for calculating the ratio of Vs / Vc after detecting the signal level Vs generated by conveying the sheet material, and a standard Means for recording a threshold value Sr at a ratio obtained in advance from the magnitude relationship between the ratio Vss / Vsc of the signal level Vss for various sheets and the signal level Vsc for the standard calibration sheet, and the result of the Vs / Vc is represented by the Sr A sheet material identification apparatus, wherein correction is performed by identifying the sheet material using the result classified in step (1).   2. The apparatus according to claim 1, wherein the calibration sheet has the same surface property on one side as a sheet having the roughest surface property among sheets that can be passed through the device and is the most sheet that can be passed through the device. The piezoelectric element portion has the same surface property as that of a smooth sheet on the other surface, and passes each surface twice in a single calibration for a total of two upper and lower roughness standards. A sheet material identification apparatus, wherein fluctuations in detection characteristics of the apparatus are corrected on the basis of signal levels generated from the apparatus.   2. The apparatus according to claim 1, wherein the calibration sheet has a surface roughness equivalent to that of a sheet having the most surface property among sheets that can be passed through the apparatus in the front half of one side and can be passed through the apparatus. It has the same surface roughness in the latter half of the same surface as the smoothest sheet in the sheet, and two types of surface roughness are detected at the same time in one calibration, and both the upper and lower limits of roughness are detected. The sheet material identification apparatus is characterized by correcting fluctuations in detection characteristics of the apparatus based on signal levels generated from the piezoelectric element portion.   5. The sheet material identification device according to claim 1, wherein ceramic particles having hardness higher than that of the probe are dispersedly applied and fixed at least in a region having a rough surface property of the calibration sheet.   6. The apparatus according to claim 1, wherein the probe has a distal end portion of the probe perpendicular to the sheet material conveyance direction and a circumferential direction around a fixed axis parallel to the conveyance plane and opposite to the sheet material conveyance direction. The tip abutting portion is configured to be able to vibrate forward and backward in the conveying direction on the conveyance plane at the probe tip, and the tip abutting portion is arranged in the conveying direction. The sheet material is conveyed while the tip of the probe is in contact with the surface of the sheet material, and the piezoelectric element portion is subjected to the unevenness of the surface of the sheet material and the friction coefficient. A sheet material having a sheet material identification function for generating an electric signal by inducing strain due to vibration and impact of each strength and identifying the surface property of the surface of the sheet material based on the electric signal intensity difference Knowledge Apparatus.   The probe according to claim 6 is an S-shaped sheet metal that is bent at two locations, the first bent portion R1 and the second bent portion R2, so that the tip end portion of the metal sheet metal is S-shaped when viewed from the side in the transport direction. A sheet material identification device using an S-shaped probe having a piezoelectric element formed on a flat portion surface between a fixed end portion of the S-shaped sheet metal and a first bent portion.   8. The apparatus according to claim 1, wherein a cumulative sheet material identification number counting unit of the apparatus is provided as the periodic calibration guiding unit, and a device display unit is provided each time the result of the counting unit reaches a predetermined number of times set in advance. Alternatively, a sheet material identification apparatus using means for transmitting a periodic calibration configuration request signal to the apparatus control host.   The sheet material identification device according to any one of claims 1 to 8, wherein a heat-resistant resin is used as the constituent sheet, and heat treatment means for heating the material to be heated that has passed through the sheet material identification device, and the sheet A heating apparatus comprising: control means for controlling the heating temperature of the heat treatment means in accordance with an identification signal of a material identification apparatus.   A sheet material identification device according to any one of claims 1 to 8, image forming means for forming a toner image on a recording material that has passed through the sheet material identification device, and heating the recording material on which the toner image has been formed. A fixing unit that pressurizes and fixes the toner image on the recording material, and a control that changes a fixing temperature of the fixing unit and a heating time or a heating processing interval of the recording material in accordance with an identification signal of the sheet material identification device. An image forming apparatus comprising: means.   11. The apparatus according to claim 10, wherein the calibration sheet is attached to a consumable part cartridge having at least a toner supply container as the periodic calibration guiding means, and the consumable part cartridge is attached to the new consumable part cartridge when the consumable part cartridge is replaced. An image forming apparatus comprising: control means for controlling the apparatus so that the apparatus can be used after calibrating with a calibration sheet.   11. The calibration apparatus according to claim 10, wherein the calibration sheet is attached to a consumable part cartridge having at least a toner supply container as the periodic calibration guiding means, and attached to the process cartridge when the consumable part cartridge is attached or detached. An image forming apparatus comprising: control means for controlling the apparatus so that the apparatus can be used after calibration with a sheet.   The sheet material identification device according to any one of claims 1 to 8, ink discharge type image forming means for forming an image by ejecting ink onto a recording material that has passed through the sheet material identification device, and the sheet material identification An image forming apparatus comprising control means for controlling an ink discharge amount of the ink discharge type image forming means in accordance with an identification signal of the apparatus.   The sheet material identification device according to any one of claims 1 to 8, and a thermal transfer image forming unit that thermally transfers ink on an ink ribbon on a recording material that has passed through the sheet material identification device, using a thermal head; An image forming apparatus comprising: control means for controlling power supplied to the thermal head of the thermal transfer image forming means in accordance with an identification signal of a sheet material identifying apparatus.   A sheet material conveying means for conveying the sheet material; and a probe having a piezoelectric element built therein, and the sheet material is conveyed while the probe tip is in contact with the surface of the sheet material, whereby the sheet is transferred to the piezoelectric element portion. In a sheet material identification device that induces an electric signal by inducing strain due to vibration and impact whose strength changes according to the frictional force with the material surface, and identifies the rigidity of the sheet material based on the electric signal strength difference, A rigidity calibration sheet having a reference rigidity necessary for calibrating the identification performance of the apparatus, and periodic calibration guiding means for periodically passing the rigidity calibration sheet through the apparatus to promote calibration, and A sheet material identification device, wherein a variation in detection characteristics of the device is corrected based on a signal level generated from the piezoelectric element portion by a calibration sheet.   16. The apparatus according to claim 15, wherein the rigidity calibration sheet is a high-rigidity calibration sheet having a rigidity equivalent to that of a sheet having the highest rigidity among sheets that can be passed through the apparatus, and a sheet that can be passed through the apparatus. Two types of low-rigidity calibration sheets with the same rigidity as the least rigid sheet are provided, and the two types of calibration sheets are passed once in a single calibration, for a total of two times. A sheet material identification device that corrects fluctuations in detection characteristics of the device based on each signal level generated from the piezoelectric element section with respect to both the lower limit and the lower limit.