JP2011063413A - Recording material carrying device, image forming device, and method for controlling the recording material carrying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately measure the thickness of a recording material while securing a sufficient friction carrying force without complicating construction. <P>SOLUTION: This recording material carrying device includes a pair of rotating rollers 24 for holding and carrying the recording material P, a measuring means 43 for measuring the distance between both rotating rollers 24, and a computing means using measurement information for the measuring means 43 for computing the thickness of the recording material P. A roller 41a of at least one of both rotating rollers 24 is formed of an elastic material. The computing means corrects the measurement information for the measuring means 43 in accordance with a passing width x of the recording material P to compute the thickness of the recording material P. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a recording material conveyance device, an image forming apparatus including the recording material conveyance device, and a recording material conveyance device control method.

  In recent years, the spread of electrophotographic and ink-jet image forming apparatuses is expanding, and their uses are expanding in various fields. In particular, in a full-color type image forming apparatus, it is desired that even thick recording materials that have been used so far can be recorded without any problem while maintaining image quality. It is known that recording on a thick recording material differs greatly in image forming conditions such as the amount of heat for fixing and transfer conditions compared to the case of plain paper. Therefore, for recording while maintaining the image quality, it is necessary to change the image forming conditions corresponding to recording materials of various thicknesses, and various techniques for measuring the thickness of the recording material have been proposed.

  As a technique for measuring the thickness of the recording material, apart from the conveying roller pair for conveying the recording material, a dedicated rigid roller pair is provided, and the thickness of the recording material is measured from the distance between the rigid roller pair. Is known (see, for example, Patent Document 1). In general, at least one of the roller portions is formed of an elastic body for the purpose of securing a conveying force due to friction. For this reason, in a state where the recording material is sandwiched between the conveying roller pair, the roller portion is elastically deformed, and the distance between the conveying roller pair and the thickness of the recording material do not match. Therefore, the thickness of the recording material is measured from the distance between the rigid roller pairs using a rigid roller pair that does not deform during nipping and conveying.

  In the above configuration, a pair of rigid rollers dedicated to thickness measurement that do not contribute to conveyance is required in addition to the pair of conveyance rollers, which causes a problem of cost increase due to an increase in the number of parts and a problem of arrangement space. In this respect, Patent Documents 2 and 3 disclose that the conveyance roller pair has a thickness measurement function (to eliminate the rigid roller pair), and that one conveyance roller is made of a rigid body, while the other conveyance roller. It is disclosed that the roller portion is divided into three parts and is formed into a composite type in which the center side is made of an elastic body and both longitudinal sides are made of a rigid body.

Japanese Patent Laying-Open No. 2003-237208 (see paragraph 0025) JP-A-60-15337 Japanese Unexamined Patent Publication No. 7-117890

  However, in the configurations of Patent Documents 2 and 3, since the other transport roller is configured as a composite type, the structure of the composite transport roller itself is complicated and the number of parts increases, which hinders cost reduction. There was a problem of becoming. Further, depending on the sheet passing width of the recording material, it is difficult to secure a sufficient conveying force with only the elastic roller portion at the center side, and there is a problem that the possibility of causing a conveyance defect cannot be denied.

  Therefore, the present invention has a technical problem to solve the above problems.

  According to a first aspect of the present invention, a thickness of the recording material is measured by using a pair of rotating rollers for nipping and conveying the recording material, a measuring unit for measuring a distance between the rotating rollers, and measurement information of the measuring unit. A recording material conveying apparatus having a computing means for computing, wherein at least one of the rotating rollers is made of an elastic material, and the computing means is based on a sheet passing width of the recording material. The thickness of the recording material is calculated by correcting the measurement information of the measuring means.

  According to a second aspect of the present invention, in the recording material conveying apparatus according to the first aspect, the roller portion of the other rotating roller is made of a rigid body, and the other rotating roller is sandwiched with respect to the one rotating roller. The recording material is conveyed so as to be movable toward and away from the thickness direction, and the measuring means is configured to measure a displacement amount of the other rotating roller.

  According to a third aspect of the present invention, in the recording material conveying apparatus according to the second aspect, in the other rotating roller, the surface roughness of the non-conveying area outside the conveying area that can come into contact with the recording material is the conveying area. The reflection type optical sensor as the measuring means is arranged in a state facing the non-conveying area of the other rotating roller.

  According to a fourth aspect of the present invention, there is provided an image forming apparatus comprising the recording material conveying apparatus according to any one of the first to third aspects.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the fourth aspect of the present invention, the image forming apparatus further includes a restricting unit that shifts the recording material before feeding to a center reference, and the calculation unit is based on position information of the restricting unit. It detects the sheet passing width of the recording material.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the fourth or fifth aspect, the both rotating rollers are upstream of the image processing apparatus that transfers the toner image formed on the image carrier onto the recording material. It is what is arranged in.

  According to a seventh aspect of the present invention, a thickness of the recording material is measured by using a pair of rotating rollers for nipping and conveying the recording material, a measuring means for measuring a distance between the rotating rollers, and measurement information of the measuring means. In a control method of a recording material conveying apparatus in which at least one of the rotating rollers is made of an elastic material, and is determined according to the sheet passing width of the recording material. A step of calculating the thickness of the recording material by correcting the distance between the two rotating rollers by multiplying the distance between the two rotating rollers by a thickness correction coefficient.

  According to the invention described in the claims of the present application, at least one of the rotating rollers that sandwich and convey the recording material is made of an elastic material, and the calculation means is configured to measure the measurement means based on the sheet passing width of the recording material. Since the thickness of the recording material is calculated by correcting the measurement information, a pair of rigid rollers dedicated to thickness measurement that do not contribute to conveyance is not necessary, and the one rotating roller does not need to be a composite type. In other words, the thickness of the recording material can be accurately adjusted without complicating the structure of the rotating roller pair (suppressing cost increase), while at least one rotating roller can secure a sufficient friction conveying force. There is an effect that it can be measured well.

1 is a schematic explanatory diagram of a printer according to an embodiment. It is a schematic perspective view of a timing roller pair. FIG. 6 is a schematic plan view of a timing roller pair in a state where a recording material having a wider sheet passing width is sandwiched. FIG. 3 is a schematic plan view of a timing roller pair in a state where a thick recording material is sandwiched. It is a functional block diagram of a controller. It is a graph of the thickness correction coefficient which is a function of the sheet passing width. It is a graph which shows the relationship between the sheet passing width and the displacement amount of a rigid roller. It is a flowchart which shows an example of thickness measurement control. It is a graph which shows the calculation result of the thickness of the recording material using a thickness correction coefficient.

  Hereinafter, an embodiment in which the present invention is applied to a tandem color digital printer (hereinafter referred to as a printer), which is an example of an image forming apparatus, will be described with reference to the drawings. In addition, in the following description, when using a term indicating a specific direction or position (for example, “left / right”, “up / down”, etc.) as necessary, the direction orthogonal to the paper surface in FIG. ing. These terms are used for convenience of explanation, and do not limit the technical scope of the present invention.

(1). First, an outline of the printer 1 will be described with reference to FIG. As shown in FIG. 1, the printer 1 includes an image processing device 3, a paper feeding device 4, a fixing device 5, and the like in a housing 2. Although not shown in detail, the printer 1 is connected to a network such as a LAN, and is configured to execute printing based on the command when receiving a print command from an external terminal (not shown). Yes.

  The paper feeding device 4 located at the lower part in the housing 2 includes a paper feeding cassette 21 that accommodates the recording material P, a pickup roller 22 that feeds the recording material P in the paper feeding cassette 21 from the uppermost layer, and a fed recording material P. A pair of separation rollers 23 that separate each sheet and a pair of timing rollers 24 that convey the recording material P separated into one sheet to the image processing apparatus 3 at a predetermined timing are provided. The recording material P in each paper feed cassette 21 is sent out one by one from the uppermost layer to the conveyance path 30 by the rotation of the pickup roller 22 and the separation roller pair 23. The conveyance path 30 passes from the paper feeding cassette 21 of the paper feeding device 4 to the upper part of the casing 2 through the nip portion of the timing roller pair 24, the secondary transfer nip portion of the image processing device 3, and the fixing nip portion of the fixing device 5. To the discharge roller pair 26 in the middle. The timing roller pair 24 constitutes a pair of rotating rollers that sandwich and convey the recording material P.

  The recording material P in the paper feed cassette 21 is set to a center reference that is conveyed in the direction of arrow S toward the conveyance path 30 with the center of the sheet passing width x (width dimension orthogonal to the conveyance direction S) as a reference. . In the embodiment, the paper feed cassette 21 is provided with a pair of side regulating plates 25 as regulating means for bringing the recording material P before feeding into the center reference. The pair of side portion regulating plates 25 are configured to move in close proximity to each other in the sheet passing width direction (direction perpendicular to the transport direction S). By sandwiching the recording material P in the paper feed cassette 21 from both sides in the sheet passing width direction by the pair of side portion regulating plates 25, the recording material P in the paper feed cassette 21 is set to the center reference regardless of the standard. . Therefore, the transfer process in the image processing apparatus 3 and the fixing process in the fixing apparatus 5 are also executed on the basis of the center. In FIG. 2, for convenience of explanation, a virtual line passing through the center of the sheet passing width x of the recording material P is represented as a center reference line CL.

  The image processing device 3 positioned above the paper feeding device 4 plays a role of transferring a toner image formed on a photosensitive member 13 which is an example of an image carrier onto a recording material P, and an intermediate transfer belt 6. , And yellow (Y), magenta (M), cyan (C), and black (K), a total of four image forming units 7 and the like are provided. The intermediate transfer belt 6 is wound around a driving roller 8 located on the right side of the central portion in the housing 2 and a driven roller 9 located on the left side of the central portion. A secondary transfer roller 10 is disposed outside the portion of the intermediate transfer belt 6 that is wound around the drive roller 8. A contact portion between the intermediate transfer belt 6 and the secondary transfer roller 10 is a secondary transfer nip portion which is a secondary transfer region. A transfer belt cleaner 12 for removing untransferred toner on the intermediate transfer belt 6 is disposed outside the portion of the intermediate transfer belt 6 wound around the driven roller 9. A control unit 28 that performs overall control of the printer 1 is disposed between the image processing apparatus 3 and the sheet feeding apparatus 4 in the housing 2. The controller 28 includes a controller 44 described later.

  The four image forming units 7 are arranged along the intermediate transfer belt 6 in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the left in FIG. They are arranged side by side. In FIG. 1, for convenience of explanation, symbols Y, M, C, and B are attached to the image forming units 7 according to the reproduction colors. Each image forming unit 7 includes a photoreceptor 13. Around the photoconductor 13, a charger 14, an exposure unit 19, a developing unit 15, a primary transfer roller 16, and a photoconductor cleaner 17 are arranged in this order along the clockwise rotation direction in FIG. 1.

  In each image forming unit 7, when a laser beam is projected from the exposure unit 19 onto the photoconductor 13 charged by the charger 14, an electrostatic latent image is formed. The electrostatic latent image is reversely developed with toner supplied from the developing unit 15 to be a toner image of each color, and in the primary transfer nip portion, yellow, magenta, cyan, and black are sequentially transferred from the photoreceptor 13 to the intermediate transfer belt. 6 is primarily transferred and superposed on the outer peripheral surface. Untransferred toner remaining on the photoreceptor 13 is scraped off by the photoreceptor cleaner 17 and removed from the photoreceptor 13. Then, when the recording material P passes through the secondary transfer nip portion, the superimposed four color toner images are secondarily transferred onto the recording material P all at once. Untransferred toner remaining on the intermediate transfer belt 6 is scraped off by the transfer belt cleaner 12 and removed from the intermediate transfer belt 6.

  The fixing device 5 positioned above the secondary transfer roller 10 in the image processing apparatus 3 includes a fixing roller 31 incorporating a heat source such as a halogen lamp heater and a pressure roller 32 facing the fixing roller 31. A contact portion between the fixing roller 31 and the pressure roller 32 is a fixing nip portion which is a fixing region. The recording material P on which the unfixed toner image is placed after passing through the secondary transfer nip portion is heated and pressurized when passing through the fixing nip portion between the fixing roller 31 and the pressure roller 32, and the recording material P An unfixed toner image is fixed thereon. Thereafter, the recording material P is discharged onto the paper discharge tray 27 by the rotation of the pair of discharge rollers 26.

(2). Next, the detailed structure of the timing roller pair 24 and its periphery will be described with reference to FIGS. The timing roller pair 24 temporarily stops the recording material P sent from the paper feed cassette 21 in a state where the leading end of the recording material P is in contact with the nip portion of the timing roller pair 24 in order to eliminate skew (skew). This is for stopping and conveying the toner image toward the secondary transfer nip portion at a timing synchronized with the toner image on the intermediate transfer belt 6. At least one roller portion 41a of the timing roller pair 24 is made of an elastic body.

  In the embodiment, the roller portion 41a of one timing roller (elastic body roller 24a) is made of an elastic body, and the roller portion 41b of the other timing roller (rigid body roller 24b) is made of a rigid body such as metal. In the description of the embodiment, for convenience, the timing roller having the elastic roller portion 41a is referred to as an elastic roller 24a, and the timing roller having the rigid roller portion 41b is referred to as a rigid roller 24b. The shaft portions of the rollers 24a and 24b are made of a rigid body such as metal. As the elastic body, EPDM (ethylene propylene rubber) which is a terpolymer of ethylene, propylene and a diene monomer is employed. Both of the roller portions 41a and 41b of the timing roller pair 24 may be made of an elastic material.

  The elastic roller 24a is pivotally supported inside the housing 2 in a rotatable but non-displaceable state, while the rigid roller 24b is supported by the recording material P that is nipped and conveyed with respect to the elastic roller 24a. It is configured to be movable toward and away from the thickness direction (arrow A direction). That is, the rigid roller 24b can approach or move away from the elastic roller 24a along the direction of the arrow A in accordance with the thickness of the recording material P being nipped and conveyed. Spring members 42 as urging means are provided on both ends of the shaft portion of the rigid roller 24b. Due to the elastic biasing force of the spring member 42, the rigid roller 24b is constantly biased in the direction approaching or contacting the elastic roller 24a. The rigid roller 24b is pressed against the elastic roller 24a by the spring member 42, so that the frictional conveying force of the roller portion 41a of the elastic roller 24a is secured against the recording material P that has reached between the timing roller pair 24. Is done. The recording material P is conveyed toward the secondary transfer nip portion with the rotation of the timing roller pair 24 using the friction conveying force of the roller portion 41a.

  The length of each roller portion 41a, 41b in the timing roller pair 24 in the sheet passing width direction is sufficiently longer than the maximum sheet passing width (for example, A3 size short side, 297 mm, etc.). The inner side of the two-dot chain line indicated on the roller portions 41 a and 41 b shown in FIGS. 2 to 4 is set to a conveyance region Ec that can contact the recording material P. The outer sides (both ends in the longitudinal direction) of the two-dot chain line in the roller portions 41a and 41b are set to a non-transport area Eac that is out of the transport area Ec. As shown in FIGS. 2 to 4, there is a timing in the vicinity of one non-conveying area Eac of the roller portion 41 b of the rigid body roller 24 b and on the extended position in the direction of arrow A where the rigid body roller 24 b contacts and separates. A reflective optical sensor 43 is disposed as a measuring means for measuring the distance between the roller pair 24. The light emitting part and the light receiving part of the reflective optical sensor 43 are opposed to the non-conveying area Eac of the roller part 41b in the rigid roller 24b. The reflective optical sensor 43 according to the embodiment receives light which is emitted by itself and irregularly reflected by the non-conveying area Eac of the roller portion 41b, and the distance to the rigid roller 24b based on the principle of triangulation (the rigid body relative to the reflective optical sensor 43). It is configured to measure the position u, u0) of the roller 24b.

  Since the conveyance area Ec of the roller portion 41b in the rigid roller 24b is an area in contact with the recording material P, it is finished as smooth as possible for the purpose of preventing the recording material P from being damaged (damaged) and preventing dirt. On the other hand, the non-conveying area Eac of the roller portion 41b is subjected to surface processing such as blasting to roughen the surface, and the surface roughness of the non-conveying area Eac of the roller portion 41b is equal to the surface roughness of the conveying area Ec. It is set to be larger than (rough). For this reason, the light impinging on the non-transport area Eac from the reflective optical sensor 43 is irregularly reflected, and triangulation using the reflective optical sensor 43 can be reliably performed. As a result, the positions u and u0 of the rigid roller 24b can be accurately measured.

  As shown in FIG. 5, the reflection type optical sensor 43 is electrically connected to a controller 44 as a calculation means. The controller 44 measures the distance Δu between the timing roller pair 24 from the measurement information of the reflective optical sensor 43, and sets the thickness correction coefficient f (x) determined according to the sheet passing width x of the recording material P to the distance Δu. By multiplying, thickness measurement control for correcting the distance Δu and approximately calculating the thickness y of the recording material P is executed. Although illustration is omitted, the controller 44 includes an EEPROM and a flash memory that constitute a storage means, a RAM that temporarily stores a control program and data, an input / output interface, and the like in addition to a CPU that executes various arithmetic processes and controls. I have. In addition to the reflection type optical sensor 43 described above, the controller 44 includes a motor drive circuit 46 of a timing motor 45 that rotationally drives the timing roller pair 24, a sheet passing width detection sensor 47 that detects the position of the side regulating plate 25, and the like. Electrically connected. Therefore, the controller 44 of the embodiment detects the sheet passing width x of the recording material P from the detection information of the sheet passing width detection sensor 47 (position information of the side portion regulating plate 25). As the sheet passing width detection sensor 47, for example, an optical sensor that reads the movement of a slit provided on the side regulating plate 25, a sensor that measures the resistance value of a conductor that the side regulating plate 25 contacts and moves, and the like. Can be adopted.

  In the storage means (flash memory or EEPROM) of the controller 44, a thickness correction coefficient f (x) determined in accordance with the sheet passing width x of the recording material P is stored in advance in a map format or a function table format, for example. (See FIG. 6). The thickness correction coefficient f (x) is a function of the sheet passing width x of the recording material P. FIG. 6 shows an inversely proportional curve that increases when the sheet passing width x is small and decreases when the sheet passing width x is large. The thickness correction coefficient f (x) is determined for each material of the roller portion 41a of the elastic roller 24a (EPDM in the embodiment), and is obtained through experiments or the like. Data indicated by white circles, triangles, and squares (◯, Δ, and □) in FIG. 6 are calculated data of the thickness correction coefficient f (x) obtained from the experimental results of FIG. The thickness correction coefficient f (x) shown in FIG. 6 is set by curve regression (curve fitting) based on these data. The graph of the experimental results in FIG. 7 shows how the sheet passing width x of the recording material P and the displacement amount Δu of the rigid roller 24b are related to the actual thickness of the recording material P. Here, the displacement amount Δu of the rigid roller 24b is based on the detection value u (position u of the rigid roller 24b) of the reflective optical sensor 43 when the recording material P is sandwiched, and the reflective optical when the recording material P is not sandwiched. The value obtained by subtracting the detection value u0 of the sensor 43 (position u0 of the rigid roller 24b) is equivalent to the distance between the timing roller pair 24 in the state where the recording material P is sandwiched.

(3). Explanation of Thickness Measurement Control Next, an example of thickness measurement control by the controller 44 will be described with reference to the flowchart of FIG. 8 and the graph of FIG. Note that the algorithm shown in the flowchart of FIG. 8 is stored as a program in storage means (EEPROM, flash memory, etc.) of the controller 44, and is read by the RAM and then executed by the CPU.

  When the image forming operation is started, the controller 44 starts the rotation of the timing roller pair 24 (step S1), and appropriately rotates every rotation phase interval (for example, a rotation phase interval of 36 ° (for example, 36 °) without holding the recording material P). Every 10 times per rotation), the distance to the rigid roller 24b is detected by the reflective optical sensor 43, and the detected value u0 is read (step S2). When the timing roller pair 24 makes one rotation (S3: YES), the average of the detection values u0 of the reflective optical sensor 43 is calculated (step S4). In step S4, the average of the detection values u0 of the reflective optical sensor 43 is calculated in order to eliminate the influence of the eccentricity of the timing roller pair 24 as much as possible. Next, the detected value (sheet passing width x of the recording material P) of the sheet passing width detection sensor 47 is read (step S5), and the conveyance of the recording material P toward the timing roller pair 24 is started (step S6). Next, when the recording material P reaches the nip portion of the timing roller pair 24 (step S7: YES), the distance to the rigid roller 24b is detected by the reflective optical sensor 43 at appropriate rotation phase intervals, and the detected value u is read (step S8). Next, when the timing roller pair 24 makes one rotation (step S9: YES), the average of the detection values u of the reflective optical sensor 43 is calculated (S10), and the displacement amount Δu (= u−u0) of the rigid roller 24b is calculated. (S11). Then, the thickness correction coefficient f (x) corresponding to the sheet passing width x read in step S5 is multiplied by the displacement amount Δu of the rigid roller 24b, thereby correcting the displacement amount Δu and correcting the thickness y ( = F (x) × Δu) is calculated (S12).

  The graph shown in FIG. 9 is a calculated value of the thickness y of the recording material P calculated by multiplying the displacement amount Δu of the rigid roller 24b by the thickness correction coefficient f (x). In FIG. 9, symbols having the same shape (circles, triangles, etc.) are a combination of recording materials P having the same thickness and different sheet passing widths x. As shown in the graph of FIG. 9, the symbols having the same shape (recording materials P having the same thickness and different sheet passing widths x) are roughly arranged side by side. It was found that the obtained thickness y was in good agreement. That is, if the correction is made with the thickness correction coefficient f (x), the thickness y of the recording material P can be obtained approximately from the displacement amount Δu of the rigid roller 24b regardless of the sheet passing width x.

(4). Summary As is apparent from the above description, according to the present invention, at least one roller portion 41a of the rotating rollers 24 sandwiching and transporting the recording material P is made of an elastic material, and the computing means 44 includes the recording material P Since the thickness y of the recording material P is calculated by correcting the measurement information of the measuring means 43 based on the sheet passing width x, a pair of rigid rollers dedicated to thickness measurement that do not contribute to conveyance is not necessary, The rotating roller 24a need not be a composite type. That is, at least one of the rotating rollers 24a can ensure a sufficient frictional conveying force, but without complicating the structure of the rotating roller pair 24 (suppressing cost increase), The thickness y can be accurately measured.

  Further, the roller portion 41b of the other rotating roller 24b is made of a rigid body, and the other rotating roller 24b is in contact with and separated from the one rotating roller 24a in the thickness direction of the recording material P that is nipped and conveyed. Since the measuring means 43 is configured to measure the displacement amount Δu of the other rotating roller 24b, it can be used over time when measuring the thickness y of the recording material P. For example, errors caused by the influence of dirt, wear, etc. on the roller portions 41a and 41b in the rotating roller pair 24 can be surely canceled. For this reason, even if used for many years, the thickness y of the recording material P can be measured with high accuracy, and the reliability of the calculation result can be sufficiently ensured.

  Furthermore, in the other rotating roller 24b, the surface roughness of the non-transport area Eac that is out of the transport area Ec that can contact the recording material P is set to be larger than the surface roughness of the transport area Ec. Since the reflection type optical sensor 43 as a means is arranged in a state facing the non-conveying area Eac of the other rotating roller 24b, the reflection type optical sensor 43 detects irregularly reflected light from the non-conveying area Eac. Easy to get. As a result, the amount of displacement Δu of the other rotating roller 24b can be accurately measured using the reflective optical sensor 43.

  Since there is a restricting means 25 for shifting the recording material P before feeding to the center reference, the calculating means 44 detects the sheet passing width x of the recording material P from the position information of the restricting means 25. The restricting means 25 for aligning the recording material P in front of the paper can also be used as a member for detecting the paper passing width x of the recording material P, which helps to suppress an increase in cost.

(5). Others The present invention is not limited to the above-described embodiment, and can be embodied in various forms. For example, a printer has been described as an example of the image forming apparatus. However, the present invention is not limited to this, and a copier, a facsimile, or a multifunction machine having these functions combined may be used. The pair of rotating rollers is not limited to the timing roller pair 24 but may be a separation roller pair 23. The measuring means is not limited to the reflective optical sensor 43 but may be a contact type limit switch or other non-contact type sensor. In addition, the configuration of each unit is not limited to the illustrated embodiment, and various modifications can be made without departing from the spirit of the present invention.

1 Printer (image forming device)
3 Image processing device 4 Paper feed device 21 Paper feed cassette 23 Separating roller 24 Timing roller pair (rotating roller pair)
24a Elastic roller (one rotating roller)
24b Rigid body roller (the other rotating roller)
25 Side regulating plate (regulating means)
41a Roller portion 41b of elastic roller Roller portion 43 of rigid roller 43 Reflective optical sensor (measuring means)
44 Controller (Calculation means)
47 Paper width detection sensor

Claims (7)

A pair of rotating rollers for nipping and conveying the recording material; measuring means for measuring a distance between the rotating rollers; and calculating means for calculating the thickness of the recording material using measurement information of the measuring means. Recording material transporting apparatus,
At least one of the rotating rollers is made of an elastic material,
The computing means computes the thickness of the recording material by correcting the measurement information of the measuring means based on the sheet passing width of the recording material.
Recording material transport device. The roller portion of the other rotating roller is made of a rigid body, and the other rotating roller is configured to be movable toward and away from the one rotating roller in the thickness direction of the recording material to be nipped and conveyed. The measuring means is configured to measure the amount of displacement of the other rotating roller.
The recording material conveying apparatus according to claim 1. In the other rotating roller, the surface roughness of the non-conveying area deviated from the conveying area that can come into contact with the recording material is set larger than the surface roughness of the conveying area, and the reflective optical sensor as the measuring means Is arranged in a state facing the non-conveying area of the other rotating roller,
The recording material conveying apparatus according to claim 2. The recording material conveying apparatus according to claim 1 is provided.
Image forming apparatus. Comprising a restricting means for shifting the recording material before feeding to a center reference, and the calculating means detects a sheet passing width of the recording material from position information of the restricting means,
The image forming apparatus according to claim 4. The rotating rollers are arranged on the upstream side of the image processing apparatus that transfers the toner image formed on the image carrier to the recording material.
The image forming apparatus according to claim 4 or 5. A pair of rotating rollers for nipping and conveying the recording material; measuring means for measuring a distance between the rotating rollers; and calculating means for calculating the thickness of the recording material using measurement information of the measuring means. In the control method of the recording material conveying apparatus, wherein at least one of the rotating rollers is made of an elastic material,
A step of calculating the thickness of the recording material by correcting the distance between the rotating rollers by multiplying the distance between the rotating rollers by a thickness correction coefficient determined according to the sheet passing width of the recording material. ing,
Control method of recording material conveying apparatus.

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