JP7098391B2 - Sheet storage device and image forming device - Google Patents

Description

The present invention relates to a sheet storage device for storing a sheet and an image forming device including the same.

Conventionally, as shown in FIG. 8, an image forming apparatus including an apparatus main body having a transfer unit for transferring an image to a sheet and an optional paper feed cassette unit 3 mounted below the apparatus main body has been proposed. (See Patent Document 1). The paper cassette unit 3 has two upper and lower paper cassettes 10 and 11 and a dehumidifying unit 17 detachably installed on the upper surface of the paper cassette 10.

The dehumidifying unit 17 has a heater main body 14, a wiring portion 15 that supplies power to the heater main body 14, and a panel portion 16 that supports the heater main body 14 and the wiring portion 15 and transfers heat from the heater main body 14. ing.

Japanese Unexamined Patent Publication No. 2009-298523

However, the heater main body 14 described in Patent Document 1 is arranged above and in the center of the paper feed cassette 10, and is configured to particularly heat the central portion of the sheet housed in the paper feed cassette 10. If the central portion of the sheet is dehumidified by the heater body 14 and the outer edge portion is not dehumidified, the outer edge portion of the sheet may be curled or wrinkled when the sheet is heated in the fixing unit. There is a risk of dehumidification.

Further, if the amount of heat of the heater main body 14 is increased in order to sufficiently dehumidify the outer edge portion of the sheet, the bottom surface of the apparatus main body or the paper feed cassette 10 may be deformed by the heat of the heater main body 14. As described above, the dehumidifying unit 17 described in Patent Document 1 could not dehumidify the sheet in a well-balanced manner.

Therefore, an object of the present invention is to provide a sheet storage device and an image forming device that solve the above-mentioned problems by heating and dehumidifying a sheet in a well-balanced manner.

INDUSTRIAL APPLICABILITY The present invention is a sheet storage device in which a printer main body is detachably mounted on an upper portion , and a frame, a drawer that can be pulled out from the frame, and a drawer that can be stored with a sheet loaded. When the printer main body is attached to the sheet storage device, the top plate including the downward recessed recess provided in the frame so that the upper surface faces the printer main body , and the drawer portion. The dehumidifying heater comprises a pickup roller that is in contact with the upper surface of the loaded sheet and feeds the sheet, and a dehumidifying heater that is installed in the recess of the top plate and heats the sheet stored in the drawer portion. A frame body and a heating element that emits heat and is arranged along the outer periphery of the frame body inside the frame body, and the area of the upper surface of the frame body can be stored in the drawer portion. The dehumidifying heater is set to be 1/4 or more of the area of the sheet surface of the maximum size sheet and equal to or less than the area of the upper surface of the top plate, and the dehumidifying heater is arranged at a position overlapping the pickup roller in the vertical direction. And.

According to the present invention, the sheet can be heated and dehumidified in a well-balanced manner, and the occurrence of curls and wrinkles on the sheet can be reduced.

The whole perspective view which shows the printer which concerns on this embodiment. An overall schematic view showing the printer body. The flowchart which shows the image formation process by an image formation part. (A) is a perspective view showing a cassette, and (b) is a perspective view showing a state in which a dehumidifying heater is attached to the cassette. (A) is a wiring diagram of a heating element according to the present embodiment, and (b) and (c) are wiring diagrams showing other wiring examples of the heating element. (A) is a plan view showing a flow path between the laser scanner and the frame, and (b) is a plan view showing the flow path between each process cartridge and the photoconductor and the frame. (A) is a perspective view showing a cassette deck according to a modified example, and (b) is a perspective view showing a state in which a dehumidifying heater is attached to the cassette deck. The perspective view which shows the conventional dehumidification unit.

Hereinafter, the sheet storage device and the image forming device according to the present embodiment will be described with reference to the drawings. The dimensions, materials, shapes, relative arrangements, etc. of the components described in the following embodiments are not intended to limit the scope of application of this technique to those alone unless otherwise specified. ..

[Outline configuration of printer]
First, a schematic configuration of the printer 300 as an image forming apparatus will be described with reference to FIG. As shown in FIG. 1, the printer 300 includes a printer main body 100 and an image reading device 200. The image reading device 200 arranged above the printer main body 100 includes a reading unit 202 and an ADF 201 in detail, and optically scans a document to read image information. The manuscript is paper such as paper and envelopes, plastic film such as transparency sheets (OHT), and sheets such as cloth. The image information converted into an electric signal by the image reader 200 is transferred to a control unit (not shown) provided in the printer main body 100.

As shown in FIG. 2, the printer main body 100 has a main body portion 61 as an apparatus main body and an optional feeder 62 connected to the lower portion of the main body portion 61. The main body 61 includes an image forming unit 120 that forms an image on a sheet that is a recording medium, a fixing device 140, a discharge roller pair 150, and a feeding unit 130 that feeds the sheet to the image forming unit 120. is doing. The feeding unit 130 includes a main body cassette 101 capable of storing a sheet, a pickup roller 131 for feeding the sheet stored in the main body cassette 101, and a separation pad 132 for separating the sheets one by one together with the pickup roller 131. have.

Similarly, the feeder 62 also has a cassette 102 capable of storing a sheet, a pickup roller 141 for feeding the sheet stored in the cassette 102, and a separation pad 142 for separating the sheet one by one together with the pickup roller 141. is doing. Although the main body cassette 101 and the cassette 102 have a middle plate (not shown) that supports the seat and can be raised and lowered, the seat is loaded on the bottom plate of the main body cassette 101 and the cassette 102 without providing the middle plate. You may.

The image forming unit 120 includes four process cartridges 121Y, 121M, 121C, 121K and a laser scanner that form toner images of four colors of yellow (Y), magenta (M), cyan (C), and black (K), respectively. It is equipped with 110. The four process cartridges 121Y, 121M, 121C, and 121K have the same configuration except that the colors of the images to be formed are different. Therefore, only the configuration of the process cartridge 121Y and the image forming process will be described, and the description of the process cartridges 121M, 121C, 121K will be omitted.

The process cartridge 121Y has a photosensitive drum 122 as an image carrier, a charging roller 123, and a developing roller 124. The photosensitive drum 122 is configured by applying an organic photoconducting layer to the outer periphery of an aluminum cylinder, and is rotated by a drive motor (not shown). An intermediate transfer belt 113 is arranged above the process cartridges 121Y, 121M, 121C, 121K. The intermediate transfer belt 113 is stretched by the drive roller 113a, the tension roller 113b, and the like, and is rotated by the drive roller 113a. Primary transfer rollers 125Y, 125M, 125C, 125K are provided inside the intermediate transfer belt 113. A secondary transfer roller 127 is arranged on the opposite side of the drive roller 113a with the intermediate transfer belt 113 interposed therebetween.

Next, the image forming operation of the printer 300 configured in this way will be described with reference to FIGS. 1 to 3. When an image signal is input to the laser scanner 110 from a personal computer or the like (not shown) or an image reading device 200, the laser light corresponding to the image signal is emitted from the laser scanner 110 onto the photosensitive drum 122 of the process cartridge 121Y.

At this time, the surface of the photosensitive drum 122 is uniformly charged to a predetermined polarity and potential in advance by the charging roller 123, and an electrostatic latent image is formed on the surface by irradiating the surface with laser light from the laser scanner 110. .. The electrostatic latent image formed on the photosensitive drum 122 is developed by the developing roller 124, and a yellow (Y) toner image is formed on the photosensitive drum 122.

Similarly, each photosensitive drum of the process cartridges 121M, 121C, 121K is also irradiated with laser light from the laser scanner 110, and magenta (M), cyan (C), and black (K) toner images are formed on each photosensitive drum. Will be done. The toner images of each color formed on each photosensitive drum are transferred to the intermediate transfer belt 113 by the primary transfer rollers 125Y, 125M, 125C, 125K, and up to the secondary transfer roller 127 by the intermediate transfer belt 113 rotated by the drive roller 113a. Be transported. The image forming process of each color is performed at the timing of superimposing the upstream toner image primaryly transferred on the intermediate transfer belt 113.

In parallel with this image forming process, the sheets housed in the main body cassette 101 or the cassette 102 are sent out by the pickup rollers 131 and 141, and separated one by one by the separation pads 132 and 142. Then, the sheet is conveyed to the registration roller pair 133 and abuts on the nip of the stopped registration roller pair 133 to correct the skew.

The registration roller pair 133 conveys the sheet in accordance with the image transfer timing, and the full-color toner image on the intermediate transfer belt 113 is transferred to the sheet by the secondary transfer bias applied to the secondary transfer roller 127. Toner. Heat and pressure are applied to the sheet on which the toner image is transferred in the fixing device 140, and the toner is melt-fixed (fixed). The sheet that has passed through the fixing device 140 is discharged to the discharge tray 151 by the discharge roller pair 150.

Here, the image forming process by the image forming unit 120 will be described with reference to the flowchart shown in FIG. The control unit of the printer 300 determines whether or not the image signal has been received (step S1). When the image signal is received (step S1: Yes), the control unit causes the laser scanner 110 to emit a laser corresponding to the image signal (step S2). Further, the control unit forms an electrostatic latent image on the photosensitive drum 122 by the laser emitted from the laser scanner 110 (step S3), and forms a toner image on the photosensitive drum 122 by the developing roller 124 (step S4).

The toner image formed on the photosensitive drum 122 of each process cartridge 121Y, 121M, 121C, 121K is transferred as a full-color toner image to the intermediate transfer belt 113 by the primary transfer rollers 125Y, 125M, 125C, 125K (step S5). .. The image on the intermediate transfer belt 113 is transferred to the sheet by the secondary transfer roller 127 (step S6), and the image forming process by the image forming unit 120 is completed.

[Dehumidifying heater]
Next, the dehumidifying heater 2 and its peripheral configuration will be described. As shown in FIG. 4A, the cassette 102 has a cassette frame 102a and a drawer portion 102b that is supported by the cassette frame 102a so as to be able to be pulled out and mounted. A sheet is supported by the drawer portion 102b.

The cassette frame 102a has a top plate 1 facing the printer main body 100 (see FIG. 2) and arranged above the drawer portion 102b, and the top plate 102c is formed with a recess 1a recessed downward. ing. That is, the top plate 1 is arranged at a position overlapping the drawer portion 102b in a plan view. As shown in FIG. 4B, a dehumidifying heater 2 for heating the sheet housed in the drawer portion 102b and the main body cassette 101 is installed in the recess 1a, and the conduction portion 1b continuous with the recess 1a is provided in the recess 1a. Wiring (not shown) connected to the dehumidifying heater 2 is arranged.

The dehumidifying heater 2 is configured in a flat plate shape so as to have a space inside, and has a frame body 2a that transfers heat and a heating element 70 that emits heat and is arranged inside the frame body 2a (FIG. 5A). See) and. As shown in FIG. 6A, the dehumidifying heater 2 is arranged at a position that does not overlap the pickup roller 141 as a feeding unit in a plan view, and as shown in FIG. 2, the dehumidifying heater 2 is arranged on the pickup roller 141 in the vertical direction. It is placed in an overlapping position. Therefore, the dehumidifying heater 2 can be installed in the feeder 62 without increasing the size of the feeder 62 as the seat storage device.

Further, as shown in FIG. 4B, the area of the upper surface 2b of the frame body 2a of the dehumidifying heater 2 is 1/4 or more of the area of the sheet surface of the maximum size sheet that can be supported by the drawer portion 102b, and the top plate. It is set to be equal to or less than the area of the upper surface of 1. In this embodiment, the area of the upper surface 2b of the frame body 2a of the dehumidifying heater 2 is set to about 2/5 of the area of the sheet surface of the maximum size sheet.
Further, as shown in FIG. 5A, the heating element 70 is arranged along the outer circumference of the frame body 2a inside the frame body 2a.

By determining the size of the frame body 2a and the wiring of the heating element 70 in this way, it is possible to reduce the temperature variation between the central portion and the outer edge portion of the dehumidifying heater 2 and transfer heat in a well-balanced manner. Then, the sheet stored in the main body cassette 101 and the drawer portion 102b can be dehumidified in a well-balanced manner, and the occurrence of curls and wrinkles on the sheet can be reduced.

The wiring of the heating element 70 is not limited to only one heating element as in the example of FIG. 5A, and the two heating elements 70 and 70a are framed as shown in FIG. 5B, for example. Wiring may be performed along the outer periphery of the body 2a. In this case, the outer edge portion of the dehumidifying heater 2 can be heated more than the central portion, and the inner side is more suitable for the main body cassette 101 and the cassette 102 having higher thermal conductivity than the outer side. Further, as shown in FIG. 5C, one heating element 70 may be wired along the outer periphery of the frame body 2a, and another heating element 70c may be wired to the central portion of the frame body 2a. In this case, the central portion and the outer edge portion of the dehumidifying heater 2 can be heated in a well-balanced manner. Not limited to the wiring example of the heating element 70 shown in FIGS. 5A to 5C, the wiring may be changed as appropriate, but the sheet can be dehumidified in a well-balanced manner according to the device. It is good to wire so that it can be done.

As shown in FIGS. 6A and 6B, the dehumidifying heater 2 is arranged below the laser scanner 110 and the process cartridges 121Y, 121M, 121C, 121K of each color and at overlapping positions in a plan view. Further, as shown in FIGS. 2 and 6A, a flow path A through which the warm air heated by the dehumidifying heater 2 passes is formed between the frame 100a of the printer main body 100 and the laser scanner 110. .. Further, as shown in FIGS. 2 and 6B, a flow path B through which the warm air passes is formed on the outside of the process cartridges 121Y and 121K, and the warm air is generated between the photosensitive drums 122. The flow paths C1, C2, and C3 to pass through are formed. These flow paths B, C1, C2, and C3 are formed between the frame 100a, the process cartridges 121Y, 121K, and each photosensitive drum 122.

There is a space between the frame 100a and the top plate 1 and between the frame 100a and the main body cassette 101 through which warm air can pass, and the bottom surface of the frame 100a, that is, the bottom surface of the printer main body 100 is filled with warm air. There is a hole through which it can pass. As shown in FIG. 2, the warm air warmed by the dehumidifying heater 2 rises through these spaces and holes, and also through the transport path CP through which the sheet passes, and passes through the flow paths A, B, C1, C2, and C3. do. As a result, the inside of the printer main body 100 can be efficiently dehumidified. In particular, in the present embodiment, since the dehumidifying heater 2 extends to the vicinity of the pickup roller 141, the dehumidifying heater 2 and the transport path CP are arranged close to each other, and the warm air heated by the dehumidifying heater 2 is generated. It is configured so that it can easily pass through the transport path CP.

Further, as shown in FIGS. 2 and 6A, dustproof glass 80 as a transparent member is arranged at the exit port where the laser of the laser scanner 110 is emitted, and is static on the surface of each photosensitive drum 122. The laser for creating the electro-latent image passes through the dustproof glass 80. Therefore, the emission port is closed with the dustproof glass 80, so that dust and the like can be prevented from entering the inside of the laser scanner 110, and dew condensation can be prevented inside the laser scanner 110. Further, since the warm air passing through the flow path B passes in the vicinity of the dustproof glass 80 and the warm air passing through the flow paths C1, C2, and C3 passes in the vicinity of each photosensitive drum 122, the dustproof glass 80 and the photosensitive drum 122 are present. Can be prevented from forming dew. As a result, it is possible to prevent the dust-proof glass 80 from condensing, reducing the amount of transmission of the laser, reducing the amount of toner supplied to the photosensitive drum 122, and thinning the toner image. Further, it is possible to prevent the photosensitive drum 122 from condensing and causing the toner image on the photosensitive drum 122 to flow.

As described above, in the present embodiment, the size of the dehumidifying heater 2 (the area of the upper surface 2b of the frame body 2a) is set to an area of 1/4 or more of the maximum size sheet that can be supported by the drawer portion 102b. The heating element 70 is wired along the outer periphery of the frame body 2a of the dehumidifying heater 2. Therefore, the sheets stored in the main body cassette 101 and the cassette 102 can be dehumidified in a well-balanced manner, and the occurrence of curls and wrinkles on the sheets can be reduced.

The feeder 62 in the present embodiment is an optional cassette connected to the lower part of the printer main body 100, but the target to which the dehumidifying heater 2 is attached is not limited to the feeder 62. For example, as shown in FIG. 7A, a cassette deck 520 having a top plate 501 is connected to the lower part of the printer main body 100, and a recess 501a formed in the top plate 501 is formed as shown in FIG. 7B. , A dehumidifying heater 502 may be attached.

Further, the dehumidifying heater 2 is not limited to the recess 1a of the top plate 1, and may be attached to, for example, the bottom plate of the printer main body 100 or the bottom plate of the cassette frame 102a. Further, although the above-described embodiment has been described using the electrophotographic printer 300, the present invention is not limited thereto. For example, the present invention can be applied to an inkjet image forming apparatus that forms an image on a sheet by ejecting an ink liquid from a nozzle.

1: Top plate / 1a: Recessed part / 2: Dehumidifying heater / 2a: Frame body / 2b: Top surface / 62: Sheet storage device (feeder) / 70: Heat generator / 80: Transparent member (dustproof glass) / 102: Cassette / 110: Laser scanner / 120: Image forming unit / 122: Image carrier (photosensitive drum) / 141: Feeding unit (pickup roller) / 100: Device body (printer body) / 300: Image forming device (printer) / A , B, C1, C2, C3: Flow path

Claims (5)

It is a sheet storage device in which the printer body is detachably attached to the top.
With the frame
A drawer that can be pulled out from the frame and can be stored with the seat loaded,
When the printer main body is mounted on the sheet storage device, a top plate including a downwardly recessed recess provided in the frame so that the upper surface faces the printer main body and the top plate.
A pickup roller that comes into contact with the upper surface of the sheet loaded in the drawer and feeds the sheet, and
A dehumidifying heater installed in the recess of the top plate and heating the sheet housed in the drawer portion is provided.
The dehumidifying heater has a frame body and a heating element that emits heat and is arranged along the outer periphery of the frame body inside the frame body.
The area of the upper surface of the frame is set to be 1/4 or more of the area of the sheet surface of the maximum size sheet that can be stored in the drawer portion and equal to or less than the area of the upper surface of the top plate.
The dehumidifying heater is arranged at a position overlapping the pickup roller in the vertical direction.
A seat storage device characterized by this. The dehumidifying heater is arranged at a position that does not overlap the pickup roller in a plan view.
The seat storage device according to claim 1. The seat storage device according to claim 1 or 2,
The printer main body portion having an image forming portion for forming an image on a sheet fed from the sheet storage device is provided.
An image forming apparatus characterized in that. The image forming unit includes an image carrier that supports a toner image and a laser scanner that emits a laser for forming an electrostatic latent image on the image carrier.
The printer main body has a flow path through which warm air heated by the dehumidifying heater passes between the frame of the printer main body and the laser scanner, and between the frame of the printer main body and the image carrier. ,
The image forming apparatus according to claim 3. The laser scanner has a transparent member through which the emitted laser is transmitted.
The image forming apparatus according to claim 4.

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