JP2016216248A - Medium placement device and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medium placement device and an image formation apparatus which can perform fine placement position setting of a sheet.SOLUTION: There is provided a medium placement device comprising: a medium placement part on which a medium is placed; a guide part which is arranged in a movable manner with respect to the medium placement part and regulates the position of the medium; a gear part 111 which has a first gear section 111a provided with a gear 111b formed with a first module and a second gear section 111c provided with a gear 111d formed with a second module different from the first module; a lock part 112 which locks the rotation of the gear part 111 with engagement with the second gear 111d; and a third gear 120a which is formed along the movement direction of the guide part and engages with the first gear 111b. The second module is smaller than the first module. There is also provided an image formation apparatus having the medium placement device.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a medium placing apparatus for placing a medium and an image forming apparatus for forming an image using a medium fed from the medium placing apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus that performs color printing or monochrome printing is provided with a medium placement device for placing a medium to be used for printing. In general, as shown in FIG. 6, a paper tray as a medium placement device is provided with a restriction member 300 for restricting the placement position of a sheet as a medium and ensuring the printing position accuracy.

  Normally, the regulating member 300 is provided with a lock member 310 for fixing the paper placement position. The lock member 310 includes a lock portion 312 having teeth 312 a that can mesh with the teeth 320 a of the rack member 320 laid in parallel with the movement direction of the regulating member 300. As shown in FIG. 7, the teeth 320 a of the rack member 320 and the teeth 312 a of the lock portion 312 mesh with each other by the urging force of the urging member 313 included in the lock member 310. When releasing the lock of the lock member 310, the lever member 311 is pushed in the direction of the arrow y in FIG. 7 so that the contact portion 311a of the lever member 311 contacts the contacted portion 312b of the lock portion 312. When the lock portion 312 moves (lifts) in the direction opposite to the biasing direction of the biasing member 313, the engagement between the teeth 320a of the rack portion 320 and the teeth 312a of the lock portion 312 is released, and the lock is released. be able to.

JP 2009-73574 A

  However, in the conventional technique, the teeth of the lock portion are worn due to deterioration over time, or the stop position of the restriction member shifts when locked due to a large external force applied when the paper tray is inserted into the image forming apparatus or when the restriction member is moved. There is a problem in that it is impossible to set a fine paper placement position.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a medium mounting apparatus and an image forming apparatus capable of finely setting a paper mounting position.

  In order to solve the above-described problems, a medium placement device according to the present invention includes a medium placement section for placing a medium, and a guide that is arranged to be movable with respect to the medium placement section and regulates the position of the medium. A gear portion having a first gear portion having a gear formed by a first module, and a second gear portion having a gear formed by a second module different from the first module; A lock portion that locks the rotation of the gear portion by meshing with the second gear, and a third gear that is formed along the moving direction of the guide portion and meshes with the first gear. The second module is smaller than the first module.

  In addition, the medium loading device according to the present invention is a gear in which a guide portion that regulates a medium loading position, and a first gear and a second gear whose module is different from the first gear are pivotally supported. A biasing portion that supplies a biasing force via meshing with the second gear with respect to a rotation axis direction that pivotally supports the first gear and the second gear; and A third gear formed along a restricting direction and meshing with the first gear is provided, wherein the second gear module is smaller than the first gear module.

  According to another aspect of the present invention, there is provided an image forming apparatus comprising: the medium placing apparatus described above; and an image forming unit that forms an image on the medium fed from the medium placing apparatus.

  According to the present invention, it is possible to provide a medium placement device and an image forming apparatus capable of finely setting the placement position of paper.

1 is a schematic configuration diagram illustrating a main configuration of a printer 10 according to an embodiment. 2 is a perspective view illustrating a configuration of a paper cassette 100 according to the present embodiment. FIG. It is a schematic diagram explaining the state of the locking member 110 at the time of locking of the near side guide 102. FIG. 3 is a partially enlarged view of a lock portion 112 of the lock member 110. It is a schematic diagram explaining the state of the lock member 110 at the time of lock release of the near side guide 102. FIG. It is a schematic diagram explaining the structure of the medium mounting apparatus based on a prior art. It is a schematic diagram explaining the structure of the locking member which concerns on a prior art.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably.

  FIG. 1 is a schematic configuration diagram illustrating a main configuration of a printer 10 as an image forming apparatus according to the present embodiment. The printer 10 according to the present embodiment is a color electronic that forms a color image by superimposing toners as four types of developers of black (K), yellow (Y), magenta (M), and cyan (C). A configuration as a photographic printer is provided.

  The printer 10 stores paper as a medium, starts from a paper cassette 100 as a medium loading device, and includes a transport roller 131, a paper feed detection unit 132, a transport roller 133 that also serves as a print timing adjustment unit, a fixing device 135, An image forming unit 134 is provided along a sheet conveyance path S formed in a substantially S shape with the conveyance detection unit 136, the conveyance roller 137, the discharge roller 138, the sheet discharge port 139, and the stacker 140 as an end point.

  The paper cassette 100 is housed in a state where the paper is stacked inside, and is detachably attached to the lower part of the printer 10. A hopping roller 130 is provided immediately above the paper cassette 100 to take out the stored paper one by one from the top and feed it to the transport roller 131. The configuration of the paper cassette 100 according to the present invention will be described later.

  The transport roller 131 is driven by a drive system (not shown), and transports the paper fed from the paper cassette 100 to the transport roller 133 that also serves as a print timing adjustment unit. The paper feed detection unit 132 is an optical or mechanical sensor, for example, and detects that the paper is fed to the transport roller 133.

  The image forming unit 134 uses photosensitive drums 20K, 20Y, 20M, and 20C as image carriers for forming an image corresponding to at least each toner color, and a light emitting diode as a light source, and the photosensitive drums 20K, 20Y, and LED heads 21K, 21Y, 21M, and 21C as exposure means for exposing 20M and 20C, and a transfer belt 22 that is stretched by a driving roller 22a and a driven roller 22b and electrostatically adsorbs and conveys the paper. A toner image is formed on the sheet conveyed by the roller 133. The sheet on which the toner image is formed on one side in the image forming unit 134 is conveyed to the fixing device 135 provided on the downstream side of the sheet conveying path.

  The fixing device 135 includes a heat generating roller 135a and a pressure roller 135b. The heat roller 135a is formed by, for example, coating a hollow cylindrical metal core made of aluminum or the like with a heat-resistant elastic layer of silicone rubber and a PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) tube thereon. Is formed by. In the core bar, for example, a heater (not shown) such as a halogen lamp is provided. The pressure roller 135b has a configuration in which, for example, a metal core made of aluminum or the like is covered with a heat-resistant elastic layer of silicone rubber and PFA is covered thereon, so that a pressure contact portion is formed between the pressure roller 135b and the heat generating roller 135a. It is arranged. When the paper on which the toner image is formed passes through the pressure contact portion formed by the heating roller 135a and the pressure roller 135b maintained at a predetermined temperature, heat and pressure are applied to the toner on the paper, and the toner Melts and the toner image is fixed.

  The conveyance detection unit 136 is an optical or mechanical sensor, for example, and detects the passage of a sheet on which a toner image is fixed. The conveyance roller 137 is driven by a driving source (not shown) and conveys the paper on which the toner image is fixed to the discharge roller 138. The discharge roller 138 is driven by a drive source (not shown), and discharges the sheet to the stacker 140 configured using the outer casing of the apparatus via the sheet discharge port 139.

  Next, the configuration of the paper cassette 100 will be described. FIG. 2 is a perspective view illustrating the configuration of the paper cassette 100. In the paper cassette 100, a back guide 101, a front guide 102, and a rear end guide 103 as guide portions, and a sheet receive plate 104 as a medium placement portion are arranged in a cassette case 107.

  The back side guide 101 and the near side guide 102 are provided with a rack part 105a and a rack part 105b, respectively, as shown in a partially enlarged view in which the A part in the figure is enlarged. The position is variable in a direction parallel to the insertion / extraction direction of the paper cassette 100 by interlocking with the pinion gear 106 that can mesh with the 105b. The rear end guide 103 is configured to be independently variable in the direction perpendicular to the insertion / extraction direction of the paper cassette 100.

  The front guide 102 can be engaged with a rack portion 120 as a third gear formed along the moving direction of the front guide 102 and locks the stop position of the front guide 102. A member 110 is provided.

  Here, the configuration of the lock member 110 according to the present invention will be described with reference to FIGS. 3 to 5. 3 is a schematic diagram for explaining a state of the lock member 110 when the front guide 102 is locked, FIG. 4 is a partially enlarged view of the lock portion 112 of the lock member 110, and FIG. 5 is a front guide 102. It is a schematic diagram explaining the state of the lock member 110 at the time of unlocking.

  As shown in FIG. 3, the lock member 110 includes a guide gear 111 as a gear part, a lock part 112, and an operation lever 113.

  The guide gear 111 includes a large gear 111a as a first gear portion and a small gear 111c as a second gear, and the large gear 111a and the small gear 11c are supported by a support shaft 111e. . The size of the teeth 111b of the large gear 111a (hereinafter, the size of the teeth is referred to as a module) is configured to be able to mesh with the teeth 120a of the rack portion 120. The module of the teeth 111d of the small gear 111c is smaller than the teeth 111b of the large gear 111a, and the number of teeth of the small gear 111c is larger than that of the large gear 111a. As the ratio of the number of teeth, it is preferable to configure the number of teeth of the small gear 111c to be about 1.5 to 3 times the number of teeth of the large gear 111a. It can be appropriately changed according to the accommodation space inside the paper cassette 100. Moreover, in this embodiment, although the large gear 111a was comprised as a spur gear, it is not restricted to this, It is also possible to comprise as a helical gear. In this case, it is applicable by making the tooth trace of the rack part 120 correspond to the tooth trace of the large gear 111a.

  The front side guide 102 provided with such a locking member 110 is such that the large gear 111a of the guide gear 111 is always meshed with the teeth 120a of the rack portion 120 formed along the moving direction of the front side guide 102. It will be held in the cassette case 107.

  The lock portion 112 is configured to be slidable in the vertical direction in the drawing along a guide 110 a provided inside the lock member 110. As shown in FIG. 4, the lock part 112 has a tooth 112b that can mesh with a tooth 111d of a small gear 111c included in the guide gear 111 on one end side of the main body part 112a, and an arrow ( 1) A pressing spring 112d is provided as a biasing portion that biases the main body 112a in the direction. In addition, a contact portion 112c is formed at a substantially central portion of the main body portion 112a so as to be able to contact the action portion 113c of the operation lever 113. By operating the operation lever 113, the main body portion 112a is moved to the guide 110a. It can slide along the vertical direction in the figure.

  The operation lever 113 is a substantially L-shaped member provided with an operation portion 113a on one end side and an action portion 113c on the other end side. The operation lever 113 is configured to be rotatable about a rotation fulcrum 113b, and the action portion 113c is brought into contact with the abutting portion 112c provided on the main body portion 112a of the lock portion 112 by the turning operation of the operation portion 113a. By releasing the action or the action, the main body 112a can slide in the vertical direction in FIG. 3 along the guide 110a.

  Next, a paper placing operation on the paper cassette 100 and an image forming operation by the printer 10 will be described. When placing a sheet on the sheet cassette 100, as shown in FIG. 5, the user presses the operation portion 113a of the operation lever 113 in the direction of the arrow (2) in the figure. Then, the operation lever 113 rotates about the rotation fulcrum 113b in the direction of the arrow (3) in the figure, so that the action portion 113c acts on the contact portion 112c provided on the main body portion 112a of the lock portion 112. Then, the main body portion 112a of the lock portion 112 slides in a direction opposite to the urging direction of the pressing spring 112d (in the direction of arrow (4) in the figure), and the teeth 111d of the small gear 111c included in the guide gear 111 and the main body portion 112a. The engagement with the teeth 112b provided on the other end side is released, and the lock portion 112 and the guide gear 111 are separated.

  The user moves the front guide 102 to a position that matches the desired paper size. After moving the near side guide 102 to a desired position, the user presses the operation portion 113a of the operation lever 113 in the direction opposite to the arrow (2) direction in FIG. Then, the operation lever 113 rotates about the rotation fulcrum 113b in the direction opposite to the direction of the arrow (3) in the figure, so that the action of the action part 113c on the lock part 112 is released. As a result, the main body portion 112a of the lock member 112 slides in the urging direction by the pressing spring 112d by the urging force of the pressing spring 112d, and is provided on the teeth 111d of the small gear 111c included in the guide gear 111 and the other end side of the main body portion 112a. The teeth 112b thus engaged with each other. Thereby, the position of the near side guide 102 is regulated by regulating the rotation of the guide gear 111. In addition, the user moves the rear end guide 103 in accordance with the paper size, so that the position of the regulation guide is adjusted, and the paper cassette 100 on which the paper is placed is set in the printer 10.

  When the paper cassette 100 is set in the printer 10 in this way, the printer 10 can start an image forming operation. For example, when image information is input from a host device (not shown), the printer 10 starts an image forming operation.

  Specifically, when the image forming unit 134 of the printer 10 receives input of image information, the photosensitive drums 20K, 20Y, 20M, and 20C start to rotate, and are charged by a charging voltage applied from a charging device (not shown). The surface is uniformly and uniformly charged. Then, the LED heads 21K, 21Y, 21M, and 21C are irradiated with light on the surfaces of the photosensitive drums 20K, 20Y, 20M, and 20C, and electrostatic latent images corresponding to the image information are formed. The electrostatic latent images formed on the surfaces of the photosensitive drums 20K, 20Y, 20M, and 20C are supplied with toner from a toner supply unit (not shown) to develop a toner image. Such a development process is performed at a predetermined timing until the sheet is conveyed to the image forming unit 134.

  Incidentally, the paper stored in the paper cassette 100 is fed out to the transport roller 131 by the hopping roller 130. The conveyance roller 131 conveys the sheet fed from the sheet cassette 100 to the conveyance roller 133 that also serves as a print timing adjustment unit. A conveyance roller 133 that also serves as a print timing adjustment unit conveys a sheet into the image forming unit 134 in response to the start of the development process in the image forming unit 134.

  The toner images developed on the surfaces of the photosensitive drums 20K, 20Y, 20M, and 20C are sequentially transferred onto the sheet conveyed while being electrostatically attracted to the transfer belt 22. The sheet that has passed through the image forming unit 134 is conveyed to the fixing device 135, and the toner image is fixed to the sheet by applying heat and pressure. The sheet on which the toner image is fixed is conveyed to the discharge roller 138 by the conveyance roller 137. The discharge roller 138 discharges the conveyed paper to the stacker 140 through the paper discharge port 139, and a series of image forming operations ends.

  By the way, the position of the paper cassette 100 set in the printer 10 is regulated by a stopper (not shown). Here, due to the impact hitting the stopper, the placed paper is strongly pressed against the back guide 101, and a force is exerted to move the back guide 101 in the back direction of the cassette mounting direction. At this time, since the back side guide 101 and the near side guide 102 are configured to move in conjunction with each other via the pinion gear 106, the near side guide 102 receives a force to move in the near direction.

  Specifically, at this time, the guide gear 111 (large gear 111a) of the lock member 110 is subjected to a rotational movement force on the rack portion 120 disposed in the cassette case 107, but the lock member 110 has a pressing spring 112d. Since the main body 112a that receives the urging force and the support shaft 111c that supports the large gear 111a and the small gear 11c are integrally provided, the urging force of the pressing spring 112d is not lost and the large gear 111a and the small gear 11c It is possible to transmit to the guide gear 111 which consists of. Since the locking force due to the engagement between the teeth 111d of the small gear 111c included in the guide gear 111 and the teeth 112b provided on the other end of the main body 112a can be kept large, the guide gear 111 (the large gear 111a ), The stop holding force of the front guide 102 is maintained without rotating on the rack portion 120 arranged in the cassette case 107.

  In the description of the present embodiment, the configuration in which the lock member 110 is provided in the front guide 102 that regulates the upstream end of the sheet in the sheet conveyance direction has been described, but the present invention is not limited thereto. Instead, the rear side guide 101 can of course be provided in the rear end guide 103 as a second guide part for regulating the end of the sheet in the direction orthogonal to the sheet transport direction. In this case, it is applicable by forming the rack portion 120 that meshes with the large gear 111 a included in the lock member 110 along the regulation direction (movement direction) of the rear end guide 103.

  As described above, according to the present embodiment, it is possible to finely set the guide position for various standard-size paper and obtain a sufficient locking force. The positional accuracy can be improved.

  INDUSTRIAL APPLICABILITY The present invention can be used for a paper cassette or a paper feeding device provided integrally with a device for setting and transporting paper as a medium. In addition to the image forming device, the paper after image formation is subjected to secondary processing. It can also be used for a post-processing apparatus.

10 Printers 20K, 20Y, 20M, and 20C Photosensitive drums 21K, 21Y, 21M, and 21C LED head 22 Transfer belt 22a Drive roller 22b Follower roller 100 Paper cassette 101 Back side guide 102 Front side guide 103 Rear end guide 104 Sheet receive plate 105a , 105b Rack portion 106 Pinion gear 107 Cassette case 110 Lock member 110a Guide portion 111 Guide gear 111a Large gear 111b Tooth 111c Small gear 111d Tooth 112 Lock portion 112a Main body portion 112b Tooth 112c Contact portion 112d Press spring 113 Operation lever 113a Operation portion 113b Rotation fulcrum 113c Action section 120 Rack section 120a Teeth 130 Hopping roller 131 Conveyance roller 132 Paper feed detection means 133 Conveyance roller 134 Image formation Portion 135 Fixing Device 135a Heating Roller 135b Pressure Roller 136 Conveyance Detection Unit 137 Conveyor Roller 138 Discharge Roller 139

Claims (9)

A medium placement unit for placing a medium;
A guide unit that is movably disposed with respect to the medium placement unit and regulates a position of the medium;
A gear portion having a first gear portion having a gear formed by a first module, and a second gear portion having a gear formed by a second module different from the first module;
A lock portion that locks rotation of the gear portion by meshing with the second gear;
A third gear formed along the moving direction of the guide portion and meshing with the first gear;
The medium mounting apparatus, wherein the second module is smaller than the first module. The guide part includes the gear part and the lock part,
The medium mounting apparatus according to claim 1, wherein the medium mounting unit includes a third gear.   The medium mounting apparatus according to claim 1, wherein the first gear portion and the second gear portion are pivotally supported on a common rotating shaft.   The medium mounting apparatus according to claim 3, wherein the lock portion includes a biasing portion that biases the second gear portion in the rotation axis direction.   The medium mounting apparatus according to claim 4, further comprising an operation unit that releases the meshing with the second gear by contacting the urging unit.   The medium mounting apparatus according to claim 1, wherein the guide part is a guide that regulates an upstream end of the medium in the medium transport direction.   The medium mounting apparatus according to claim 1, wherein the guide unit is a guide that regulates a medium end in a direction orthogonal to a conveyance direction of the medium. A guide part for regulating the placement position of the medium;
A gear portion in which a first gear and a second gear having a module different from the first gear are pivotally supported;
An urging unit that supplies an urging force to the rotation axis direction that pivotally supports the first gear and the second gear through meshing with the second gear;
A third gear formed along the regulation direction of the guide portion and meshed with the first gear;
The medium loading device, wherein the second gear module is smaller than the first gear module. The medium mounting apparatus according to any one of claims 1 to 8,
An image forming apparatus comprising: an image forming unit configured to form an image on the medium fed from the medium placing apparatus.