JP2012192993A - Recording medium storing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording medium storing device which can specify all recording medium sizes promptly and accurately, and an image forming apparatus provided with the same.SOLUTION: A paper feed tray 200 includes: a placement table 240; a feed roller 205; a wall member 201a that is touched by a recording medium conveyance direction tip of the recording medium S and restricts a position of the tip; a following roller 208 that is rotated along with the conveyance of the recording medium S; a rotation detecting mechanism that detects the rotation amount of the following roller 208; and a controller 250 that measures the distance to a rear end position of the recording medium S on the placement table 240 from the following roller 208, based on the rotation amount of the following roller 208 detected by the rotation detecting mechanism and the circumference length of the following roller 208, when the recording medium S is conveyed by the feed roller 205, and adds the measured distance to the design distance from the following roller 208 to the wall member 201a to calculate a sub-scanning direction length of the recording medium S.

Description

  The present invention relates to a recording medium storage device that stores a recording medium, and an image forming apparatus such as a copying machine, a facsimile machine, and a printer equipped with the recording medium storage device.

  In this type of image forming apparatus, a driven roller is brought into contact with the surface of a sheet to be conveyed, and a driving mechanism is adjusted according to a result of measuring a rotation amount of the driven roller, thereby correcting a sheet feeding amount. Those are known (for example, see Patent Document 1). The one described in Patent Document 1 is configured such that a driven roller with an encoder is brought into contact with the paper for the purpose of correcting the feed amount of the roll paper.

  Further, as this type of image forming apparatus, there is known an apparatus in which a sheet passage detection sensor is provided in the middle of the conveyance path and the length of the sheet is specified from the passage time interval (for example, patents). Reference 2). The apparatus described in Patent Document 2 is configured to stop image formation when the length of a sheet detected by a sheet passage detection sensor is different from a preset recording medium size.

  However, since the one described in Patent Document 1 is configured for the purpose of correcting the amount of roll paper feed, there is a problem in that the length of the cut paper cannot be specified. Further, if the length of the cut sheet is specified, there is a problem that the driven roller must be rolled for the entire length of the sheet to be measured.

  Further, the device described in Patent Document 2 has a problem that it cannot cope with a change in the conveyance speed of the paper and a problem that a detailed size of the paper cannot be specified. In addition, since a paper passage detection sensor is provided in the middle of the conveyance path, when using a large size paper, the length of the paper is detected before the end of the length detection by the paper passage detection sensor. There was a problem of reaching.

  As described above, in the conventional image forming apparatus, it is necessary for the driven roller to roll all the sheets in order to specify the length of the sheet, and there is a variation in the detected sheet length depending on the sheet speed. There was a problem of being big.

  The present invention has been made to solve such a problem, and provides a recording medium storage device capable of specifying all recording medium sizes quickly and accurately, and an image forming apparatus including the recording medium storage device. Objective.

  The recording medium storage device according to the present invention includes a mounting table on which the recording medium is mounted, a transport unit that transports the recording medium mounted on the mounting table one by one, and a front end portion of the mounting table in the recording medium transport direction. And a wall member that restricts the position of the leading end of the recording medium that is placed on the mounting table in contact with the recording medium in the recording medium conveyance direction, and is disposed at a predetermined position behind the wall member in the recording medium conveyance direction. A driven roller that abuts on the recording medium on the mounting table and rotates following the conveyance of the recording medium by the conveying unit, a rotation amount detecting unit that detects a rotation amount of the driven roller, and the conveying unit. When the recording medium is conveyed, from the driven roller to the rear end position of the recording medium on the mounting table based on the rotation amount of the driven roller and the circumferential length of the driven roller detected by the rotation amount detecting means. Measure the distance of A sub-scanning direction length calculating unit that adds the measured distance to a design distance from the driven roller to the wall member to calculate a sub-scanning direction length of the recording medium. And

  With this configuration, since the length of the recording medium is measured by the mounting table, the recording medium size can be quickly identified as compared with the case where the length of the recording medium is measured in the middle of the conveyance path as in the past. Can do. Further, since the length of the recording medium is measured by detecting the rotation amount of the driven roller, it is possible to accurately specify any recording medium size regardless of fluctuations in the conveyance speed of the recording medium. Therefore, any recording medium size can be specified quickly and accurately.

  In addition, the recording medium storage device according to the present invention includes a driven roller retracting unit that retracts the driven roller to a retracted position that does not prevent the recording medium from being placed when the recording medium is mounted on the mounting table.

  With this configuration, it is possible to prevent the recording medium placement from being obstructed by the driven roller when the recording medium is placed on the placement table.

  Further, in the recording medium storage device according to the present invention, the rotation amount detecting means includes a rotating body that is coaxially rotated with the driven roller and formed with a slit, and a transmission type sensor that detects transmission and light shielding of the slit of the rotating body. It is characterized by having.

  With this configuration, the amount of rotation of the driven roller can be detected satisfactorily.

  Further, in the recording medium storage device according to the present invention, the rotation amount detection means includes a rotating body that is coaxially rotated with the driven roller and formed with a slit, a reflective sensor that detects the unevenness of the slit of the rotating body, It is characterized by having.

  With this configuration, even when the rotation detection member cannot be disposed so as to sandwich the rotating body, the rotation amount of the driven roller can be detected well.

  Further, in the recording medium storage device according to the present invention, the rotation amount detection means includes a rotating body that is coaxially rotated with the driven roller and has a pattern formed thereon, and an encoder sensor that detects the pattern of the rotating body. It is characterized by.

  With this configuration, the rotation amount of the driven roller can be detected in good detail and the rotation amount detection means can be reduced in size.

  The recording medium storage device according to the present invention is characterized in that the mounting table is inclined so that the wall portion is at a low level.

  With this configuration, since the leading end of the recording medium abuts against the wall portion by its own weight, the leading end of the recording medium can be aligned by its own weight.

  In the recording medium storage device according to the present invention, the mounting table includes a bottom plate that can be raised to lift the recording medium.

  With this configuration, the recording medium can be transported regardless of the number of remaining recording media.

  Also, the recording medium storage device according to the present invention is a pair of regulation that abuts both ends in the main scanning direction of the recording medium loaded on the mounting table to regulate the position of the recording medium in the main scanning direction to a predetermined position. A member, a restricting member driving means for moving at least one of the pair of restricting members, and the restricting member starts to move from a standby position where the pair of restricting members are spaced apart from each other. Controlling the restricting member driving means so as to abut on the scanning direction end and restrict the recording medium to a predetermined position and stop, and measure the amount of movement of the restricting member from the standby position to the stop position, Main scanning direction length calculating means for calculating the length of the recording medium in the main scanning direction based on the amount of movement.

  With this configuration, it is possible to cope with recording media having different sizes in the main scanning direction, and it is possible to measure the size in the main scanning direction steplessly.

  In the recording medium storage device according to the present invention, the recording medium mounting surface of the mounting table has a bent portion bent in the recording medium sub-scanning direction, and the driven roller is supported at a position facing the bent portion. And a pressing member that presses the recording medium against the mounting table by the driven roller.

  With this configuration, since the recording medium is pressed against the bent portion of the mounting table by the pressing member via the driven roller, the recording medium is bent and placed in a state in which the rigidity in the main scanning direction is increased. It is possible to prevent the recording medium from being deformed when the recording medium is restricted by the member.

  In the recording medium storage device according to the present invention, the sub-scanning direction length calculating means may perform sub-scanning of at least the first recording medium conveyed when there are a plurality of recording media on the mounting table. The direction length is calculated.

  With this configuration, the length of the recording medium in the sub-scanning direction can be quickly specified by calculating the length of the recording medium transported first in the sub-scanning direction.

  In the recording medium storage device according to the present invention, the main scanning direction length calculation unit calculates the main scanning direction length of the recording medium, and the sub scanning direction length calculation unit calculates the length of the recording medium in the sub scanning direction. The length is calculated by a series of operations, and the length of the recording medium in the sub-scanning direction and the length in the main scanning direction are specified at a time.

  With this configuration, the sub-scanning direction length and the main scanning direction length of the recording medium can be specified at a time.

  The image forming apparatus according to the present invention includes: the recording medium storage device; and an image forming unit that forms an image on a recording medium stored in the recording medium storage device. The main scanning direction length of the recording medium calculated by the main scanning direction length calculation unit and the sub scanning direction of the recording medium calculated by the sub scanning direction length calculation unit before the recording medium reaches the unit. The image size to be formed on the recording medium is determined according to the direction length.

  With this configuration, the image size can be determined in advance before the recording medium reaches the image forming unit.

  According to the present invention, it is possible to provide a recording medium storage device that can quickly and accurately specify any recording medium size and an image forming apparatus including the recording medium storage device.

1 is a schematic configuration diagram of an image forming apparatus including a recording medium storage device according to an embodiment of the present invention. 1 is a perspective view illustrating a schematic configuration of a paper feed tray according to an embodiment. It is a figure which shows the rotation detection mechanism of the driven roller of the paper feed tray of one Embodiment. It is a figure which shows the other example of the rotation detection mechanism of the driven roller of the paper feed tray of one Embodiment. It is a side view of the paper feed tray of one embodiment. It is sectional drawing of the paper feed tray of one Embodiment. It is sectional drawing of the other example of the paper feed tray of one Embodiment. It is a flowchart which shows operation | movement of the paper feed tray of one Embodiment.

  Hereinafter, a case where the present invention is applied to a copying machine (hereinafter referred to as a copying machine 100) that is an image forming apparatus that forms an image by an electrophotographic method will be described as an example. In this embodiment, a configuration in which the image forming apparatus is a copying machine will be described. However, other image forming apparatuses such as a printer and a facsimile may be used.

  First, the basic configuration of the copying machine 100 will be described. FIG. 1 is a schematic configuration diagram showing a copying machine 100 according to the present embodiment. The copying machine 100 includes a printer unit 1, a paper feeding device 40, and a document conveyance reading unit 50. The document conveyance reading unit 50 includes a scanner unit 150 that is a document reading device fixed on the printer unit 1 and an ADF 51 that is a document conveyance device supported by the scanner unit 150.

  The paper feeding device 40 separates the fed recording medium S from the feeding roller 43 that feeds the recording medium S (transfer paper) from two paper feeding cassettes 42 arranged in multiple stages in the paper bank 41 and feeds the paper. A separation roller 45 supplied to the path 44 is provided. In addition, a plurality of conveyance rollers 46 that convey the recording medium S to the paper conveyance path 37 of the printer unit 1 are also provided. The paper feeding device 40 feeds the recording medium S in the paper feeding cassette 42 into the paper transport path 37 in the printer unit 1.

  The scanner unit 150 fixed on the printer unit 1 has a fixed reading unit 151 and a moving reading unit 152 as reading means for reading an image of the document MS. A fixed reading unit 151 having a light source, a reflection mirror, an image reading sensor such as a CCD, etc. is disposed immediately below a first contact glass (not shown) fixed to the upper wall of the casing of the scanner unit 150 so as to contact the original MS. ing. When the document MS conveyed by the ADF 51 passes over the first contact glass, the image reading sensor 153 receives the light from the light source through the plurality of reflection mirrors while sequentially reflecting the light emitted from the light source on the document surface. . Thereby, the document MS is scanned without moving the optical system including the light source and the reflection mirror.

  On the other hand, the moving reading unit 152 is disposed directly below a second contact glass (not shown) fixed to the upper wall of the casing of the scanner unit 150 so as to come into contact with the document MS, and is arranged on the right side of the fixed reading unit 151 in the drawing. Therefore, an optical system including a light source, a reflection mirror, and the like can be moved in the left-right direction in the drawing. Then, in the process of moving the optical system from the left side to the right side in the figure, the light emitted from the light source is reflected by a document (not shown) placed on the second contact glass and then passed through a plurality of reflecting mirrors. The light is received by an image reading sensor 153 fixed to the scanner body. Thereby, the original MS is scanned while moving the optical system. In this way, the scanner unit 150 scans the document MS and, based on the image information obtained by the image reading sensor 153, the optical writing device 2 drives the light source, as will be described later, to form four drum-shaped photoconductors. 4 (K, Y, M, C) is irradiated with laser light L.

  The printer unit 1 includes four image forming units 3 (K, Y, M, and C) that form toner images of colors K, Y, M, and C by writing light from the optical writing device 2, and a transfer unit 90. , A paper conveyance unit 28, a registration roller pair 33, a fixing device 60, and the like. Then, a light source such as a laser diode or LED (not shown) disposed in the optical writing device 2 is driven to write light toward the four drum-shaped photoconductors 4 (K, Y, M, C). Irradiate (laser light). By this irradiation, an electrostatic latent image is formed on the surface of the photoreceptor 4 (K, Y, M, C) which is a latent image carrier, and this latent image is developed into a toner image through a predetermined development process. The Note that the subscripts K, Y, M, and C added after the reference sign indicate specifications for black, yellow, magenta, and cyan. The toners corresponding to the respective colors are made of resin materials colored in the respective colors, and these resin materials are fixed on the recording medium S by applying heat and pressure in a fixing device 60 described later.

  Each of the image forming units 3 (K, Y, M, and C) supports the photosensitive member 4 that is a latent image carrier and various devices disposed around the photosensitive member 4 as a unit by a common support. It can be attached to and detached from the copying machine 100 main body. Taking the black image forming unit 3K as an example, this has a developing device for developing the electrostatic latent image formed on the surface of the photosensitive member 4K into a black toner image in addition to the photosensitive member 4K. In addition, it has a drum cleaning device or the like that cleans transfer residual toner adhering to the surface of the photoreceptor 4K after passing through a primary transfer nip for K described later. In the copying machine 100, a so-called tandem type in which four image forming units 3 (K, Y, M, and C) are arranged so as to face an intermediate transfer belt 91, which will be described later, along the endless movement direction. It is configured.

  The four image forming units 3 (K, Y, M, C) will be described. The four image forming units 3 (K, Y, M, and C) have substantially the same configuration except that the colors of the toners to be used are different from each other. Therefore, the subscripts of K, Y, M, and C are omitted. Hereinafter, this is simply referred to as an image forming unit 3.

  The image forming unit 3 includes a charging roller of a charging device, a developing device, a drum cleaning device, a static elimination lamp of a static elimination device, and the like around the photosensitive member 4.

  In the copying machine 100, a drum-shaped member in which a photosensitive layer is formed by coating a photosensitive organic photosensitive material on a base tube made of aluminum or the like is used as the photosensitive member 4. However, an endless belt may be used as the photoreceptor.

  The developing device carries a two-component developer containing a magnetic carrier (not shown) and a non-magnetic toner on a developing roller which is a developer carrying member, and a photosensitive member in a developing region which is a facing portion between the developing roller and the photosensitive member 4. The toner is supplied to the electrostatic latent image on 4 to make the electrostatic imagination visible. Further, the developing device includes a developer accommodating portion that accommodates the two-component developer supplied to the surface of the developing roller, and the developer accommodating portion is provided with a stirring member (not illustrated) that agitates the two-component developer accommodated. Yes. The developing roller includes a non-magnetic cylindrical developing sleeve that is rotatably arranged, and a magnet roller that is non-rotatably provided in the developing roller. The magnet roller has a plurality of magnetic poles that are sequentially arranged in the rotation direction of the developing sleeve. Each of these magnetic poles applies a magnetic force to the two-component developer on the developing sleeve at a predetermined position in the rotational direction. As a result, the two-component developer in the developer accommodating portion is attracted and carried on the surface of the developing sleeve, and a magnetic brush is formed along the magnetic force lines on the surface of the developing sleeve. The magnetic brush is transported to the developing area after being regulated to an appropriate layer thickness when passing through a position facing a developer regulating member (not shown) as the developing sleeve rotates. Then, development is performed by transferring toner onto the electrostatic latent image by a potential difference between the developing bias applied to the developing sleeve and the electrostatic latent image on the photoreceptor 4. Further, the two-component developer constituting the magnetic brush that has passed through the developing region and then returned to the developing device as the developing sleeve rotates again is affected by the repulsive magnetic field formed between the magnetic poles of the magnet roller. After detachment from the surface, the developer is returned to the developer container. A toner concentration sensor (not shown) is disposed in the developer accommodating portion, and the toner concentration of the two-component developer in the developer accommodating container is within a predetermined range based on the detection result by the toner concentration sensor. As described above, a toner replenishing device (not shown) is controlled so that an appropriate amount of toner is replenished to the two-component developer.

  In the printer unit 1, the photosensitive members 4 (K, Y, M, C) of the four image forming units 3 (K, Y, M, C) are subjected to K, Y, M by the image forming process described so far. , C toner images are formed.

  A transfer unit 90 is disposed below the four image forming units 3 (K, Y, M, C). The transfer unit 90 includes an intermediate transfer belt 91 as a toner image carrier that is stretched by a plurality of stretching rollers. A belt cleaning unit is disposed at a position facing the first stretching roller with the intermediate transfer belt 91 interposed therebetween. The device is arranged. The belt cleaning device is arranged to remove toner remaining on the intermediate transfer belt 91 after passing through a secondary transfer nip described later. In the transfer unit 90, the intermediate transfer belt 91 is moved endlessly in the clockwise direction in the drawing while being in contact with the photosensitive member 4 (K, Y, M, C). As a result, primary transfer nips for K, Y, M, and C where the photoreceptors 4 (K, Y, M, and C) and the intermediate transfer belt 91 abut are formed. In the vicinity of the primary transfer nips for K, Y, M, and C, the intermediate transfer belt 91 is moved by the primary transfer roller for each color of the primary transfer device disposed on the inner side of the belt loop. It is pressed toward C). A primary transfer bias is applied to each of the four primary transfer rollers by a power source (not shown). Thus, in the primary transfer nip for K, Y, M, and C, the primary transfer that electrostatically moves the toner image on the photoreceptor 4 (K, Y, M, and C) toward the intermediate transfer belt 91 that is a transfer body. An electric field is formed. In the drawing, toner images are sequentially superimposed on the surface of the intermediate transfer belt 91 that sequentially passes through the primary transfer nips for K, Y, M, and C along with the endless movement in the clockwise direction. Primary transcription. By this primary transfer of superposition, a four-color superposed toner image (hereinafter referred to as a four-color toner image) is formed on the surface of the intermediate transfer belt 91. The primary transfer apparatus of the present embodiment employs a configuration including a primary transfer roller as a primary transfer member, but a conductive brush, a non-contact corona charger, or the like can also be employed as the primary transfer member.

  Untransferred toner that has not been primarily transferred to the intermediate transfer belt 91 adheres to the surface of the photoreceptor 4 after passing through the primary transfer nip. The transfer residual toner is removed from the surface of the photosensitive member 4 by the drum cleaning device of the image forming unit 3, and is collected and reused in the developing device by a collecting screw and a toner recycling device (not shown).

  The printer unit 1 includes a paper transport unit 28 as a secondary transfer unit that moves endlessly over a paper transport belt below the transfer unit 90 in the drawing. In the copying machine 100, a secondary transfer nip is formed in which the paper transport unit 28 and the intermediate transfer belt 91 are in contact with each other.

  A registration roller pair 33 is disposed on the right side of the secondary transfer nip in the figure. The registration roller pair 33 feeds the recording medium S sandwiched between the rollers to the secondary transfer nip at a timing at which the recording medium S can be synchronized with the four-color toner image on the intermediate transfer belt 91. In the secondary transfer nip, the four-color toner images on the intermediate transfer belt 91 are collectively transferred to the recording medium S due to the influence of the secondary transfer electric field and the nip pressure, and combined with the white color of the recording medium S to form a full-color image. The recording medium S that has passed through the secondary transfer nip and has the toner image transferred to the surface thereof is separated from the intermediate transfer belt 91 and conveyed to the fixing device 60 by the paper conveying unit 28.

  The transfer residual toner that has not been transferred to the recording medium S at the secondary transfer nip adheres to the surface of the intermediate transfer belt 91 that has passed through the secondary transfer nip. This transfer residual toner is scraped off and removed by a belt cleaning device arranged so that the cleaning member contacts the intermediate transfer belt 91.

  The recording medium S transported to the fixing device 60 is sent out from the fixing device 60 and discharged onto the paper discharge tray 10 after the full-color toner image is fixed in the fixing device 60.

  The copying machine 100 includes a switchback device 36 that is a reversing device below the paper transport unit 28 and the fixing device 60. When image formation is performed on both sides of the recording medium S, the path of the recording medium S that has undergone image fixing processing on one side is switched to the switchback device 36 side by controlling the switching claw, and the recording medium S is reversed there. Then, it is conveyed again toward the secondary transfer nip. Then, the recording medium S that has been subjected to the secondary image transfer process and the fixing process on the other side is discharged onto the discharge tray 10.

  The copying machine 100 also includes a paper feed tray 200 that feeds the recording medium S on the side surface of the housing.

  As shown in FIG. 2, the paper feed tray 200 is positioned at the inclined housing 201 and both end portions in the side surface direction of the housing 201, and the main scanning direction (width direction) of the recording medium S (shown by a broken line). And restricting members 202 and 203 which are restricting members for restricting the position. In addition, the paper feed tray 200 includes a bottom plate 204 that is movable up and down in order to send the recording medium S to a paper feed mechanism (not shown) inside the copying machine 100 at the bottom of the casing 201. The paper feed tray 200 includes a control unit 250 that controls each part of the paper feed tray 200.

  When the recording medium S is placed on the bottom plate 204, the recording medium S is detected by a sheet presence / absence sensor (not shown), and the regulating member 202 and the regulating member 203 are brought into contact with the end of the recording medium S in the main scanning direction. The drive is applied until it comes into contact with the recording medium S, stops moving, and presses the end surface of the recording medium S, so that the position of the recording medium S can be regulated.

  The paper feed tray 200 includes a feed roller 205, which is a part of the paper feed device, at the bottom of the housing 201. The feed roller 205 is driven by a drive unit (not shown) and is loaded with a plurality of stacked recordings. The uppermost recording medium S of the medium S is sent to the next process.

  The paper feed tray 200 includes a table 206 at the end of the housing 201. The casing 201 and the table 206 constitute a mounting table 240 on which the recording medium S is mounted. The upper surface of the table 206 that is the recording medium mounting surface of the mounting table 240 and the upper surface of the bottom plate 204 are connected at a predetermined angle. In other words, the bent portion 241 is provided at the boundary between the upper surface of the table 206 and the upper surface of the bottom plate 204. Accordingly, the recording medium S placed on the placing table 240 is lightly bent in the surface direction along the upper surface of the table 206 and the upper surface of the bottom plate 204.

  As described above, since the strength of the recording medium S is increased by slightly bending the recording medium S by providing an angle between the upper surface of the table 206 and the upper surface of the bottom plate 204, recording is performed by the regulating members 202 and 203. When the medium S is sandwiched from both ends, the deformation of the recording medium S by the restriction members 202 and 203 is prevented, and the restriction of the position of the recording medium S by the restriction members 202 and 203 can be facilitated. ing.

  The paper feed tray 200 includes a pressing member 207 at a position facing the boundary between the bottom plate 204 and the table 206. The holding member 207 is a member for holding down the recording medium S from being lifted by the bent portion 241 that is a boundary portion between the bottom plate 204 and the table 206. The pressing member 207 has a driven roller 208 at a position where it comes into contact with the recording medium S.

  The driven roller 208 is configured to rotate following the movement of the recording medium S when the recording medium S is fed into the housing of the copying machine 100 by a paper feeding device such as the feeding roller 205. The installation location of the driven roller 208 is not limited to the example shown in FIG. 1, and can follow the movement of the recording medium S regardless of the location on the paper feed tray 200. The driven roller 208 is not necessarily arranged at the central portion of the recording medium S in the main scanning direction (width direction), and may be arranged so as to be biased to one side of the main scanning direction as long as it can contact the recording medium S. I do not care.

  The presser member 207 is rotatable about the rotation shaft 207a so that the recording medium S can be placed without difficulty.

  When the recording medium S is mounted on the mounting table 240, the pressing member 207 is driven by a driving mechanism (not shown) so that the driven roller 208 is rotated around the rotation shaft 207a so as to be separated from the mounting table 240. It comes to move. As a result, when the recording medium S is placed, the placement space for the recording medium S can be widened.

  The pressing member 207 is driven by a driving mechanism (not shown) after the recording medium S is mounted on the mounting table 240 so that the driven roller 208 sandwiches the recording medium S with the mounting table 240. It rotates around the rotation shaft 207a. Thereby, after the recording medium S is placed, the pressing member 207 sandwiches the recording medium S between the driven roller 208 and the placing table 240 and presses the recording medium S.

  As shown in FIG. 3, a rotation detection mechanism 231 that detects the rotation of the driven roller 208 is provided in the vicinity of the driven roller 208. The rotation detection mechanism 231 includes a disk-shaped disk slit 209 disposed coaxially with the driven roller 208 so as to rotate in synchronization with the driven roller 208. A plurality of slits 209 a extending radially from the center of rotation are provided on the rotation surface of the disk slit 209.

  The rotation detection mechanism 231 includes a transmission type sensor 210 that is fixed to the pressing member 207 via the bracket 211 and detects the rotation of the disk slit 209 by transmitting and blocking the slit 209a. The transmissive sensor 210 has a light emitting portion and a light receiving portion (not shown) arranged on both sides of the rotating surface so as to sandwich the rotating surface of the disk slit 209.

  In the configuration of FIG. 3, the amount of rotation (rotation angle, number of rotations) of the driven roller 208 is measured based on the number of passing through the slits 209 a of the disk slit 209 detected by the transmission sensor 210, and the circumference of the driven roller 208 is further measured. The moving distance of the recording medium S is converted from the length.

  The rotation detection mechanism 231 may be configured as shown in FIG. In FIG. 4, the rotation detection mechanism 231 has a disk-shaped disk slit 209 disposed coaxially with the driven roller 208 so as to rotate in synchronization with the driven roller 208 as in FIG. 3. The disk slit 209 is provided with a plurality of slits 209a extending radially from the center of rotation.

  The rotation detection mechanism 231 includes a reflective sensor 220 that is fixed to the pressing member 207 via the bracket 211 and detects the rotation of the disk slit 209 by reflected light from the slit 209a. The reflective sensor 220 is disposed on one side of the rotating surface of the disk slit 209, and irradiates light on the rotating surface of the disk slit 209 to detect the reflected light from the rotating surface, whereby the unevenness of the slit 209a of the disk slit 209 is detected. Is supposed to be detected.

  In the configuration of FIG. 4, the amount of rotation (rotation angle, number of rotations) of the driven roller 208 is measured based on the number of irregularities of the slit 209 a of the disk slit 209 detected by the reflective sensor 220. The moving distance of the recording medium S is obtained from the circumference.

  In the transmission type sensor 210 of the rotation detection mechanism 231 in FIG. 3, it is necessary to dispose two sensor members, a light emitting unit and a light receiving unit, on both sides of the rotation surface of the disk slit 209. In some cases, the two sensor members cannot be arranged on both sides of the surface.In such a case, as shown in FIG. 4, by using the reflective sensor 220 that only needs to be arranged on one side of the rotating surface of the disk slit 209, The amount of rotation of the driven roller 208 can be measured.

  Although not shown, the rotation detection mechanism 231 of the driven roller 208 is disposed coaxially with the driven roller 208 so as to rotate in synchronization with the driven roller 208, and has a pattern formed on the surface thereof. The structure which consists of an encoder sensor which detects the pattern of a rotary body can be used. In this case, the rotation detection mechanism can be reduced in size, and the detailed rotation amount of the driven roller 208 can be measured.

  As shown in FIG. 5, when the driven roller 208 is disposed on the rear end side in the recording medium transport direction with respect to the front end portion of the recording medium S in the mounting table 240, the case where the recording medium S is first placed is a case. The recording medium S is abutted against the wall member 201 a formed at the lower end portion of the 201.

  Also, as shown in FIG. 6, since the distance in the recording medium conveyance direction from the wall member 201a to the driven roller 208 is constant, if this distance is A, the driven roller 208 is moved to the recording medium S at the start of paper feeding. The recording medium S is conveyed from the state where it is already in contact with the surface, and the rotation amount of the driven roller 208 until the trailing end of the recording medium S passes through the driven roller 208 is detected and determined in advance. By obtaining the sum of the distance A from the leading end of the recording medium S to the driven roller 208 and the distance B from the driven roller 208 to the trailing end of the recording medium S obtained from the rotation amount and circumferential length of the driven roller 208, The length of the recording medium S in the sub-scanning direction (length in the transport direction) can be calculated.

  A recording medium separation mechanism (not shown) that separates one recording medium S from a recording medium bundle composed of a plurality of recording media S is disposed on the downstream side (conveying direction front end side) of the feed roller 205. When one recording medium S passes through the driven roller 208, the next recording medium S is stopped. Therefore, even when a plurality of recording media S are set, the recording medium S is one. Similarly, the trailing end missing of the recording medium S can be determined by stopping the driven roller 208.

  As shown in FIG. 5, the bottom plate 204 is rotated up to the rising position 204a by a drive mechanism (not shown) with the rear end side of the bottom plate 204 in the recording medium conveyance direction as a rotation fulcrum. Even when the remaining number of recording media S on 204 decreases, the uppermost recording medium S can pass above the wall member 201a. In addition, you may employ | adopt the structure which raises the whole bottom plate 204 in parallel, without rotating the bottom plate 204. FIG.

  In the present embodiment, the casing 201 is inclined so that the front end of the internal recording medium S faces downward. For this reason, the leading edge of the recording medium S naturally strikes and aligns with the wall member 201a due to the self-weight effect of the recording medium S, so that it is possible to prevent the leading edge of the recording medium S from being misaligned.

  As shown in FIG. 7, the housing 201 may have a flat shape, and a wall member 212 that is a member different from the housing 201 may be attached to the housing 201. When the recording medium S is placed, the wall member 212 is lowered to the tip end specified position (position indicated by a solid line in FIG. 7) to regulate the tip position of the recording medium S. When transporting the recording medium S, a transport path through which the recording medium S passes can be created by retreating the wall member 212 to a retracted position (a position indicated by a broken line in FIG. 7).

  The configuration is not limited to the configuration in which the uppermost recording medium S of the recording medium bundle is transported, and may be configured to transport the lowermost recording medium S of the recording medium bundle. In the latter configuration, specifically, Instead, the feed roller 213 is disposed, and the driven roller 214 is disposed instead of the driven roller 208, whereby the lowest recording medium S of the recording medium bundle can be conveyed.

  In the case of the system using the wall member 212 as shown in FIG. 7, the effectiveness is high because the wall member 212 can be withdrawn from the recording medium S sent from below without difficulty.

  In the case where the feed roller 213 is disposed in place of the feed roller 205 and the driven roller 214 is disposed in place of the driven roller 208, the driven roller 214 is a great obstacle to placing the recording medium S. Since it is located at a portion that does not become necessary, it is not necessary to retreat when the recording medium S is placed.

  FIG. 8 is a diagram showing a control flow for determining the recording medium size. In FIG. 8, the recording medium S is expressed as a sheet.

  First, the restricting members 202 and 203 are stopped at the farthest position (step S1). In this step, the restricting members 202 and 203 are moved to the most opened position and are kept waiting.

  Next, it is determined whether or not there is a recording medium S on the mounting table 240 (step S2). Next, the regulating member driving motors 202a and 203a are driven in the normal direction to move the regulating members 202 and 203 in the clamping direction (step S3).

  Next, it is determined whether or not the regulating members 202 and 203 are stopped with the recording medium S sandwiched from the side (step S4). Next, the recording medium width (length in the main scanning direction) is calculated from the separation distance between the regulating members 202 and 203 (step S5).

  Next, the driving of the regulating member driving motors 202a and 203a is stopped (step S6). Next, the feeding roller 205 is driven to start recording medium feeding (step S7).

  Next, it is determined whether or not the trailing end of the recording medium S has passed through the driven roller 208 (step S8). In this step, it is determined that the trailing end of the recording medium S has passed through the driven roller 208 on the condition that the trailing end of the recording medium S has finished passing the driven roller 208 and the driven roller 28 has stopped.

  Next, the recording medium length (sub-scanning direction length) is calculated (step S9). In this step, the distance B obtained from the distance A described above (the distance from the driven roller 208 to the leading edge of the recording medium S), the amount of rotation until the driven roller 208 starts moving and stops, and the circumferential length of the driven roller 208. The sum of the distance from the driven roller 208 to the rear end of the recording medium S is calculated as the recording medium length.

  Next, the recording medium size is determined (step S10). In this step, the recording medium size (size of the entire recording medium) is determined from the recording medium width obtained in step S5 and the recording medium length obtained in step S9.

  According to the control flow of FIG. 8, when the rear end of the recording medium S passes the driven roller 208, the size of the entire recording medium is determined as the recording medium size in response to the determination of the main / sub scanning length and the sub scanning length. Since the recording medium is quickly determined, the recording medium size is determined before the recording medium S reaches the main body of the copying machine 100 and the electrophotographic process is performed. The recording medium size is used as a specified value in the copying machine 100. be able to.

  After specifying the length of the first recording medium S in the recording medium bundle, the subsequent recording medium S is assumed to be the same size, and the recording medium S following the size acquired in the first recording medium S is assumed. You may use it as the size. In this case, it is not necessary to measure the size of the subsequent recording medium S.

  Further, a plurality of recording media S including the first recording medium S in the recording medium bundle may be continuously measured. In this case, it is possible to prevent the measurement result from becoming unstable due to the deviation of the tip position of the recording medium S as the number of recording media passes.

  As described above, in the present embodiment, the driven roller 208 is configured to contact the recording medium S so that the driven roller 208 can rotate in accordance with the conveyance of the recording medium S. Then, the uppermost or lowermost recording medium S of the loaded sheet bundle is separated and conveyed. At this time, the driven roller 208 that rotates following the recording medium S is provided on the recording medium S. When the trailing end passes through the driven roller 208, the recording medium S to be transported next is still stopped. Therefore, the driven roller 208 is stopped. You can observe. By measuring the rotation amount of the driven roller 208 with a sensor, the distance from the start of movement of the driven roller 208 to the trailing edge of the recording medium S can be calculated. Furthermore, the position of the driven roller 208 in the sub-scanning direction is always fixed at a fixed position by applying the tip of the recording medium S to the wall member 201a so that the tip position of the recording medium S is always constant. The length of the recording medium S can be specified from the sum of the distance calculated from the sensor.

  In a conventional image forming apparatus, even a sensor that detects only the leading edge and trailing edge of a recording medium can measure the length of the recording medium if the conveyance speed of the recording medium is constant. The value fluctuates due to variations in the load applied to the recording medium due to the bending of the conveyance path, or the conveyance control is restricted. In the present embodiment, the driven roller 208 is rotated along with the movement of the recording medium S, and the paper length is measured with good follow-up regardless of the conveyance state of the recording medium S, that is, the recording medium S It is possible to measure the length in the scanning direction. In the present embodiment, the regulating members 202 and 203 are automatically operated, and the operation amounts of the regulating members 202 and 203 are measured. Therefore, the length of the recording medium S in the main scanning direction is measured steplessly. can do.

  As described above, the paper feed tray 200 according to the present embodiment includes the mounting table 240 on which the recording medium S is mounted, and the feed roller 205 that transports the recording medium S mounted on the mounting table 240 one by one. A wall member 201a that is erected at the front end portion in the recording medium conveyance direction of the mounting table 240 and that the recording medium conveyance direction front end of the recording medium S placed on the mounting table 240 abuts to regulate the position of the front end; A driven roller 208 that is disposed at a predetermined position behind the member 201 a in the recording medium conveyance direction, contacts the recording medium S on the mounting table 240, and is driven to rotate as the recording medium S is conveyed by the feed roller 205, and the driven roller 208. When the recording medium S is conveyed by the feed roller 205, the rotation amount of the driven roller 208 detected by the rotation detection mechanism 231 and the circumference of the driven roller 208 are detected. The distance from the driven roller 208 to the rear end position of the recording medium S on the mounting table 240 is measured, and the measured distance is added to the design distance from the driven roller 208 to the wall member 201a. And a control unit 250 for calculating the length in the sub-scanning direction.

  With this configuration, since the length of the recording medium S is measured by the mounting table 240, the recording medium size can be quickly identified as compared with the case where the length of the recording medium S is measured in the middle of the conveyance path as in the past. It can be performed. Further, since the length of the recording medium S is measured by detecting the rotation amount of the driven roller 208, any recording medium size can be specified accurately regardless of fluctuations in the conveyance speed of the recording medium S. Therefore, any recording medium size can be specified quickly and accurately.

  In addition, the paper feed tray 200 according to the present embodiment controls the driven roller 208 under the control of the control unit 250 so that the driven roller 208 is retracted so that the recording medium is not hindered when the recording medium is mounted on the mounting table 240. The pressing member 207 that supports 208 is rotated.

  With this configuration, it is possible to prevent the recording medium placement from being obstructed by the driven roller 208 when the recording medium is placed on the placement table 240.

  Further, in the paper feed tray 200 according to the present embodiment, the rotation detection mechanism 231 detects the transmission and shading of the disk slit 209 in which the slit 209a is formed by rotating coaxially with the driven roller 208 and the slit 209a of the disk slit 209. And a transmissive sensor 210.

  With this configuration, the rotation amount of the driven roller 208 can be detected satisfactorily.

  Further, in the paper feed tray 200 according to the present embodiment, the rotation detection mechanism 231 has a disk slit 209 that is coaxially rotated with the driven roller 208 to form a slit 209a, and a reflection that detects irregularities of the slit 209a of the disk slit 209. And a type sensor 221.

  With this configuration, even when the rotation detection member cannot be disposed so as to sandwich the disk slit 209, the rotation amount of the driven roller 208 can be detected satisfactorily.

  Further, in the sheet feeding tray 200 according to the present embodiment, the rotation detection mechanism 231 includes a rotating body that is coaxially rotated with the driven roller 208 and has a pattern formed thereon, and an encoder sensor that detects the pattern of the rotating body. It is characterized by.

  With this configuration, the amount of rotation of the driven roller 208 can be detected in good detail and the rotation detection mechanism 231 can be downsized.

  In addition, the paper feed tray 200 according to the present embodiment is characterized in that the mounting table 240 is inclined and installed such that the wall member 201a is at a low level.

  With this configuration, since the leading end of the recording medium S abuts against the wall member 201a with its own weight, the leading end of the recording medium S can be aligned with its own weight.

  Further, the paper feed tray 200 according to the present embodiment is characterized in that the mounting table 240 includes a bottom plate 204 that can be raised to lift the recording medium S.

  With this configuration, the recording medium S can be transported regardless of the number of remaining recording media S.

  Further, the paper feed tray 200 according to the present embodiment is in contact with both ends in the main scanning direction of the recording medium S stacked on the mounting table 240 and regulates the main scanning direction position of the recording medium S to a predetermined position 1. The pair of restricting members 202 and 203, the motors 202a and 203a for moving at least one of the pair of restricting members 202 and 203, and the restricting members 202 and 203 are in a standby state where the pair of restricting members 202 and 203 are separated to the maximum. The motors 202a and 203a are controlled so as to start moving from the position, come into contact with the end portion in the main scanning direction of the recording medium S and stop the recording medium S at a predetermined position, and the standby positions of the regulating members 202 and 203 And a control unit 250 that measures the amount of movement from the stop position to the stop position and calculates the length of the recording medium S in the main scanning direction based on the amount of movement.

  With this configuration, it is possible to cope with recording media S having different sizes in the main scanning direction, and it is possible to measure the size in the main scanning direction steplessly.

  Further, in the paper feed tray 200 according to the present embodiment, the recording medium mounting surface of the mounting table 240 has a bent portion 241 that is bent in the recording medium sub-scanning direction, and the driven roller 208 is opposed to the bent portion 241. And a pressing member 207 that is supported at a position and presses the recording medium S against the mounting table 240 by a driven roller 208.

  With this configuration, since the recording medium S is pressed against the bent portion 241 of the mounting table 240 by the pressing member 207 via the driven roller 208, the recording medium S is bent and placed in a state where rigidity in the main scanning direction is increased. Thus, it is possible to prevent the recording medium S from being deformed when the recording medium S is regulated by the regulating members 202 and 203.

  Further, in the paper feed tray 200 according to the present embodiment, the control unit 250, when there are a plurality of recording media S on the mounting table 240, at least the first recording medium S transported in the sub-scanning direction. The length is calculated.

  With this configuration, by calculating the length in the sub-scanning direction of the first recording medium S that is transported, the length in the sub-scanning direction of the recording medium S can be quickly identified.

  Further, in the paper feed tray 200 according to the present embodiment, the control unit 250 calculates the length of the recording medium S in the main scanning direction and the length of the sub-scanning direction by a series of operations and performs the sub-recording of the recording medium S. The length in the scanning direction and the length in the main scanning direction are specified at a time.

  With this configuration, the sub-scanning direction length and the main scanning direction length of the recording medium S can be specified at a time.

  The copying machine 100 according to the present embodiment includes a paper feed tray 200 and the printer unit 1 that forms an image on the recording medium S stored in the paper feed tray 200. Before the recording medium S reaches 1, the image size formed on the recording medium S is determined according to the main scanning direction length and the sub-scanning direction length of the recording medium S calculated by the control unit 250. And

  With this configuration, the image size can be determined in advance before the recording medium S reaches the printer unit 1.

  As described above, the recording medium storage device and the image forming apparatus according to the present invention have the effect of being able to quickly and accurately specify any recording medium size, and the recording medium storage for storing the recording medium. The present invention is useful as an image forming apparatus such as a copying machine, a facsimile machine, and a printer equipped with the apparatus and the recording medium storage apparatus.

1 Printer section (image forming means)
100 Copying machine (image forming device)
200 Paper feed tray (recording medium storage device)
201 Housing 201a, 212 Wall member 202, 203 Restriction member 202a, 203a Motor (regulation member driving means)
204 Bottom plate 204a Ascending position 205, 213 Feed roller (conveying means)
206 Table 207 Presser member 207a Rotating shaft 208, 214 Followed roller 209 Disc slit (rotating body)
209a Slit 210 Transmission type sensor 211 Bracket 220 Reflection type sensor 221 Reflection type sensor 231 Rotation detection mechanism (rotation amount detection means)
240 Mounting table 241 Bending portion 250 Control unit (sub-scanning direction length calculating means, main scanning direction length calculating means)
S Recording medium

JP 2004-249532 A JP 2008-065309 A

Claims (12)

A mounting table for mounting the recording medium;
Conveying means for conveying the recording medium placed on the mounting table one by one;
A wall member that is erected at a recording medium conveyance direction front end portion of the mounting table and that regulates a position of the front end by contacting a front end of the recording medium placed on the mounting table in a recording medium conveyance direction;
A driven roller that is disposed at a predetermined position behind the wall member in the recording medium conveyance direction, contacts the recording medium on the mounting table, and rotates following the conveyance of the recording medium by the conveying unit;
A rotation amount detecting means for detecting the rotation amount of the driven roller;
When the recording medium is transported by the transporting means, the recording medium on the mounting table is moved from the driven roller based on the rotation amount of the driven roller detected by the rotation amount detecting means and the circumferential length of the driven roller. Measure the distance to the rear end position and add the measured distance to the design distance from the driven roller to the wall member to calculate the sub-scanning direction length of the recording medium And a recording medium storage device.   2. The recording medium storage device according to claim 1, further comprising driven roller retracting means for retracting the driven roller at a retracted position that does not interfere with the recording medium mounting when the recording medium is mounted on the mounting table.   The rotation amount detecting means includes a rotating body that is coaxially rotated with the driven roller and formed with a slit, and a transmission type sensor that detects transmission and light shielding of the slit of the rotating body. 2. A recording medium storage device according to 1.   2. The rotation amount detection unit includes a rotating body that is coaxially rotated with the driven roller and formed with a slit, and a reflective sensor that detects unevenness of the slit of the rotating body. Recording medium storage device.   The recording medium according to claim 1, wherein the rotation amount detection unit includes a rotating body that is coaxially rotated with the driven roller and has a pattern formed thereon, and an encoder sensor that detects a pattern of the rotating body. Storage device.   The recording medium storage device according to claim 1, wherein the mounting table is inclined and installed such that the wall member is at a low level.   The recording medium storage device according to claim 1, wherein the mounting table includes a bottom plate that can be raised to lift the recording medium. A pair of regulating members that respectively abut on both ends in the main scanning direction of the recording medium loaded on the mounting table and regulate the position of the recording medium in the main scanning direction to a predetermined position;
Restriction member driving means for moving at least one of the pair of restriction members;
The restricting member starts to move from a standby position where the pair of restricting members are spaced apart to the maximum, contacts the end of the recording medium in the main scanning direction, and stops the recording medium at a predetermined position. A main scanning direction length for controlling the regulating member driving means, measuring a movement amount of the regulating member from a standby position to a stop position, and calculating a main scanning direction length of the recording medium based on the movement amount The recording medium storage device according to claim 1, further comprising: a length calculation unit. The recording medium mounting surface of the mounting table has a bent portion bent in the recording medium sub-scanning direction,
The recording medium storage according to claim 8, further comprising: a pressing member that supports the driven roller at a position facing the bent portion and presses the recording medium against the mounting table by the driven roller. apparatus.   The sub-scanning direction length calculation means calculates the sub-scanning direction length of at least one recording medium transported first when there are a plurality of recording media on the mounting table. The recording medium storage device according to any one of claims 1 to 9.   The main scanning direction length calculation unit calculates the main scanning direction length of the recording medium and the sub-scanning direction length calculation unit calculates the sub-scanning direction length of the recording medium in a series of operations. 11. The recording medium storage device according to claim 8, wherein the sub-scanning direction length and the main scanning direction length of the medium are specified at a time. A recording medium storage device according to any one of claims 8 to 11,
Image forming means for forming an image on a recording medium stored in the recording medium storage device;
Before the recording medium reaches the image forming unit from the recording medium storage device, the main scanning direction length of the recording medium calculated by the main scanning direction length calculating unit and the sub-scanning direction length calculating unit An image forming apparatus, wherein an image size to be formed on the recording medium is determined according to the calculated sub-scanning direction length of the recording medium.

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