Image forming device

Abstract

To provide an image forming device capable of saving the space of a structure for blowing air to a sheet.SOLUTION: An image forming device comprises: image forming means for forming an image on a sheet; a tray rotatably disposed on the side face of a device body in which the image forming means is housed, and having a placement surface on which the sheet is placed; feeding means for feeding the sheet placed on the placement surface to the image forming means; and blower fans which are attached to the tray, generate air to be blown toward the side ends of the sheet in the sheet width direction orthogonal to the sheet feeding direction of the feeding means, and are arranged such that they are located on the side opposite to the side where the sheet is placed with respect to the placement surface, and at least part of a position of the blower fan in the sheet width direction overlaps with a position of the placement surface in the sheet width direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an image forming apparatus that forms an image on a sheet.

Background Art

[0002] In recent years, even in electrophotographic image forming apparatuses used in offices, there has been a demand for high-quality and high-image-quality products using special papers such as coated paper and thick paper. However, these special papers are difficult to separate and feed one by one from a stacked sheet bundle compared to general office papers and recycled papers because they have high surface smoothness and are likely to stick to each other.

[0003] Patent Document 1 describes a technique for assisting sheet separation by blowing air onto the side edge of a sheet bundle set on a manual tray.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration of the above document, the blower protrudes outside the sheet loading area on the manual tray, and the apparatus has become larger by the space for arranging the blower.

[0006] Therefore, an object of the present invention is to enable space saving in a configuration for blowing air onto a sheet.

Means for Solving the Problems

[0007] One aspect of the present invention is an image forming apparatus comprising: an image forming means for forming an image on a sheet; a tray rotatably provided on the side of a main body of an apparatus housing the image forming means and having a mounting surface on which a sheet is placed; a feeding means for feeding the sheet placed on the mounting surface toward the image forming means; and a blower fan attached to the tray and generating air to be blown toward the side edge of the sheet in the sheet width direction perpendicular to the direction of feeding of the sheet by the feeding means, wherein the blower fan is positioned on the side opposite to the mounting surface on which the sheet is placed, and such that at least a portion of the position of the blower fan in the sheet width direction coincides with the position of the mounting surface in the sheet width direction. [Effects of the Invention]

[0008] According to the present invention, it is possible to reduce the space required for the air supply configuration to the sheet. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic diagram of the image forming apparatus according to Example 1. [Figure 2] A block diagram showing the control system of the image forming apparatus according to Example 1. [Figure 3] A schematic diagram of the manual feeding unit according to Example 1, viewed from above. [Figure 4] A schematic diagram (a, b) showing a cross-section of the manual feeding section according to Example 1. [Figure 5] A schematic diagram showing a cross-section of the manual feeding unit according to Example 1. [Figure 6] A schematic diagram of the manual feeding unit according to Example 1, viewed from above. [Figure 7] A schematic diagram of the manual feeding unit according to Example 1, viewed from above. [Figure 8] A detailed view of the manual feeding unit according to Example 1, seen from above. [Figure 9] A detailed diagram showing the inside of the feeding tray according to Example 1. [Figure 10] A detailed view showing a cross-section of the manual feeding unit according to Example 1. [Figure 11] Schematic view of the manual feed unit according to Example 2, seen from above. [Figure 12] Schematic view showing a cross-section of the manual feed unit according to Example 2. [Figure 13] Schematic view of the manual feed unit according to Example 3, seen from above. [Figure 14] Schematic view showing a cross-section of the manual feed unit according to Example 3. [Figure 15] Schematic view of the manual feed unit according to Example 4, seen from above. [Figure 16] Schematic view showing a cross-section of the manual feed unit according to Example 5. [Figure 17] Schematic view showing a cross-section of the manual feed unit according to Example 6. [Figure 18] Schematic view of the image forming apparatus according to Example 1.

Best Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings.

[0011] In the present disclosure, an "image forming apparatus" refers to an apparatus that forms an image on a sheet as a recording material. The image forming apparatus includes a printer, a copier, a multifunction peripheral, a commercial printing machine, and the like.

[0012] 《Example 1》 (Image Forming Apparatus) FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus 201 according to an embodiment (Example 1). The image forming apparatus 201 is a tandem type and intermediate transfer type laser beam printer that uses an electrophotographic process. The image forming apparatus 201 can form and output a full-color or monochromatic image on a sheet S based on image data. As the sheet S, various sheets of different sizes and materials can be used, such as paper such as plain paper and thick paper, plastic film, cloth, sheet materials with surface treatment such as coated paper, and special-shaped sheet materials such as envelopes and index paper.

[0013] As shown in Figure 1, the image forming apparatus 201 comprises an apparatus body 201A that houses the image forming unit 201B, an image reading device 300 positioned above the apparatus body 201A to read image information from the original, and a control unit 100 (Figure 2) that controls the operation of the entire apparatus. The image forming unit 201B, which is an example of an image forming means, includes four process units PY, PM, PC, and PK, an exposure device 210, a transfer belt 216, and a fixing device 201E. A discharge space V for sheet discharge is formed between the image reading device 202 and the apparatus body 201A.

[0014] Each process unit PY, PM, PC, and PK includes a photosensitive drum 212 as an image carrier and a charging device 213, a developing device 214, a cleaning device, etc., as process means acting on the photosensitive drum 212. The photosensitive drum 212 is an electrophotographic photoreceptor formed in a drum shape. The developing device 214 contains one of the following toners as a developer: yellow, magenta, cyan, or black. The exposure device 210, as a process means (exposure means), is located below the process units PY, PM, PC, and PK.

[0015] The transfer belt 216 is an example of an intermediate transfer body. The transfer belt 216 is wrapped around the drive roller 216a and the tension roller 216b. Inside the transfer belt 216, four primary transfer rollers 219 are positioned opposite the photosensitive drum 212, on either side of the transfer belt 216. The transfer belt 216 rotates counterclockwise in the figure by the drive roller 216a, which is driven by a drive unit (not shown). A secondary transfer roller 217 is positioned outside the transfer belt 216, opposite the drive roller 216a, on either side of the transfer belt 216. A transfer section 201D (secondary transfer section) is formed as a nip between the secondary transfer roller 217 and the transfer belt 216.

[0016] A fixing device 201E is positioned above the transfer unit 201D. The fixing device 201E is a thermal fixing type having a heating roller 220b heated by a heating means such as a halogen lamp, and a pressure roller 220a that is pressed against the heating roller 220b. Further above the fixing device 201E are a first discharge roller pair 225a, a second discharge roller pair 225b, and a double-sided reversal unit 201F. The double-sided reversal unit 201F includes a reversible reversible roller pair 222 and a re-conveying path R.

[0017] An operating unit 730 for receiving user input is provided at the top of the image forming apparatus 201. The operating unit 730 includes a display device such as a liquid crystal panel for displaying images, and input devices such as a numeric keypad and a print execution button. For example, the user can input setting information (type, basis weight, size, brand, etc.) for the sheet S set in the cassette feeding unit 230 and the manual feed feeding unit 235 via the operating unit 730.

[0018] A cassette feeding unit 230 is located at the bottom of the main body 201A of the device. A manual feeding unit 235 is located on the side of the main body 201A of the device. The cassette feeding unit 230 and the manual feeding unit 235 are examples of sheet feeding devices that feed sheets.

[0019] The cassette feeding unit 230 includes a cassette 1 as a sheet storage means for storing sheets S, and a pickup roller 2 as a feeding means for feeding sheets S from the cassette 1. The cassette feeding unit 230 also includes a pair of separation rollers consisting of a feed roller 3 and a retard roller 4 as a separation and transport unit for separating the sheets P sent out by the pickup roller 2. The retard roller 4 applies a frictional force to the sheets S in the opposite direction to the feeding direction at the nip between it and the feed roller 3, thereby allowing only one sheet S in contact with the feed roller 3 to pass through the nip.

[0020] Figure 2 is a block diagram showing the system configuration of the image forming apparatus 201. The control unit 100 is a control means that comprehensively controls the operation of the image forming apparatus 201 and exchanges information with the host device 900 and the operation unit 730. The control unit 100 also controls the operation of the image forming unit 201B and the feeding and transport of sheets. Here, the host device 900 is a personal computer, image scanner, facsimile, etc. The storage unit 101 stores the programs executed by the control unit 100 and the data necessary for the execution of those programs. The storage unit 101 also provides a workspace for the control unit 100 when executing programs.

[0021] The control unit 100 controls the operation of the image forming apparatus 201 based on setting information input by the user via the operation unit 730 and image data received from the host device 900. For example, the control unit 100 controls the sheet feeding operation by driving the actuator (motor, etc.) of the manual feed unit 235. Also, based on the sheet setting information, the control unit 100 activates the blower fans 15a and 15b described later if it determines that separation by blowing air is necessary (for example, in the case of coated paper).

[0022] (Image formation process) The control unit of the image forming apparatus 201 starts the image forming operation when it receives image data from an external source or when it receives a copy operation instruction and the image reading device 300 receives image data read from the original. In the image forming operation, each process unit PY, PM, PC, PK forms a toner image on the surface of the photosensitive drum 212 by an electrophotographic process. That is, when the process units PY, PM, PC, PK are requested to form a toner image, the photosensitive drum 212 is rotated, and the charging device 213 uniformly charges the surface of the photosensitive drum 212. The exposure device 210 irradiates the photosensitive drum 212 with laser light based on the image data received by the control unit from an external source or the image data read from the original by the image reading device 300. As a result, the surface of the photosensitive drum 212 is exposed and an electrostatic latent image is formed. The developing device 214 supplies a developer containing toner to the photosensitive drum 212 and develops the electrostatic latent image into a toner image.

[0023] The toner images formed by the process units PY, PM, PC, and PK are first transferred to the transfer belt 216 by the primary transfer roller 219. When forming a full-color image, the primary transfer is performed so that the toner images of each color overlap on the transfer belt 216, thereby forming a color image on the transfer belt 216. Any toner or other deposits remaining on the photosensitive drum 151 are removed by the cleaning devices of each process unit PY, PM, PC, and PK.

[0024] In parallel with the operation of the image forming unit 201B, the sheets S are fed one by one from the cassette feeding unit 230 or the manual feeding unit 235 and transported to the registration roller pair 240. After correcting the skew of the sheets S, the registration roller pair 240 transports the sheets S to the transfer unit 201D at a timing synchronized with the operation of the image forming unit 201B. Then, in the transfer unit 201D, the toner image is secondarily transferred from the transfer belt 216 to the sheets S by the secondary transfer roller 217 to which a transfer voltage is applied.

[0025] The sheet S, having passed through the transfer section 201D, is sent to the fixing device 201E. The fixing device 201E heats and pressurizes the toner image on the sheet S while transporting it by sandwiching it between the heating roller 220b and the pressure roller 220a. This results in an image fixed to the sheet S. Due to the adhesive force of the molten toner, a force is generated on the sheet S that causes it to stick to the heating roller 220b. If the rigidity of the sheet S is low (weak), there is a possibility that the sheet S will be wound up by the rotating heating roller 220b, so a separation plate 221 for separating the sheet is provided downstream of the heating roller 220b.

[0026] In the case of single-sided printing, the sheet S that has passed through the fuser 201E is discharged into the discharge space V by the first discharge roller pair 225a or the second discharge roller pair 225b and loaded onto the discharge tray 223. In the case of double-sided printing, the sheet S, which has an image formed on the first surface by passing through the transfer unit 201D and the fuser 201E, is inverted by the reversing roller pair 222 and transported again to the image forming unit 201B via the retransport path R. Then, the sheet S passes through the transfer unit 201D and the fuser 201E again to form an image on the second surface, and is then discharged into the discharge space V by the first discharge roller pair 225a or the second discharge roller pair 225b and loaded onto the discharge tray 223.

[0027] In the above description, the image forming unit 201B is an example of an image forming means, and a direct transfer type electrophotographic unit, or an inkjet type or offset printing type image forming unit may also be used.

[0028] (Manual feed unit) The manual feed unit 235, which has an air blowing section, will be explained with reference to Figure 3. Figure 3 is a schematic view of the manual feed unit 235 from above. Unlike the cassette feed unit 230, which can store a large number of sheets, the manual feed unit 235 is configured to allow the user to set only the amount of sheets they need when using the image forming apparatus 201. Therefore, the cassette feed unit 230 is suitable for using plain paper and standard-sized sheets that are used frequently, while the manual feed unit 235 is suitable for using less frequently used sheets such as coated paper and long paper.

[0029] In the following description, "feeding direction Y" refers to the direction in which the sheet is fed out of the feeding tray 5 by the pickup roller 502. "Sheet width direction X" refers to the direction along the sheet loaded on the feeding tray 5, which is perpendicular to the feeding direction Y.

[0030] The manual feed unit 235 includes a feed tray 5, a pickup roller 502, a feed roller 503, a retard roller 504, side end guides 14a, 14b, and blower fans 15a, 15b.

[0031] The feed tray 5 is a tray (loading member) on which sheets are loaded. The feed tray 5 has a mounting surface 5a (a support surface that supports the lower surface of the sheet, a loading surface) on which the sheet is placed. The feed tray 5 is rotatable (openable and closable) around a support part 5e (hinge part) between a storage position (see Figure 18) in which it is housed in the side of the main body 201A of the image forming apparatus 201 and a feed position that protrudes to the outside of the main body 201A and allows for the feeding of sheets. With the feed tray 5 open, the user can set a sheet in the feed tray 5. The feed tray 5 is also called a manual feed tray or a multi-purpose tray.

[0032] The pickup roller 502 is an example of a feeding means for feeding sheets. The pickup roller 502 is positioned above the mounting surface 5a of the feeding tray 5. The pickup roller 502 is rotatably supported by a roller holder, which acts as a holding member. The roller holder is pivotable about the rotation axis of the feed roller 503. As the roller holder pivots, the pickup roller 502 moves between a feeding position (contact position, lower position) where it contacts the upper surface of the sheets loaded on the feeding tray 5, and a standby position (separated position, upper position) where it is separated upward from the sheets. As the pickup roller 502 rotates in the feeding position, sheets are fed out of the feeding tray 5 in the feeding direction Y. Instead of the pickup roller 502, a mechanism may be used in which, for example, a negative pressure generated by a fan attracts sheets to a belt, and the sheets are transported by rotating the belt.

[0033] The feed roller 503 further transports the sheet received from the pickup roller 502 in the feeding direction Y. Downstream of the feed roller 503, a transport roller pair 506 is arranged to transport the sheet received from the feed roller 503 toward the registration roller pair 240 (Figure 1).

[0034] The retard roller 504 is pressed against the feed roller 503, forming a separation nip between them. The retard roller 504 is also driven by a torque limiter in the opposite direction to the rotation of the feed roller 503. The retard roller 504 is an example of a separation member that separates the sheet by frictional force, and may be a roller member connected to a fixed shaft via a torque limiter, or a pad-shaped elastic member that contacts the feed roller 503.

[0035] The side edge guides 14a and 14b are regulating members (regulating plates) that restrict the position of the sheet in the sheet width direction X. In this embodiment, a pair of side edge guides 14a and 14b facing each other in the sheet width direction X are used. The side edge guide 14b on the back side is a second side edge guide that faces the sheet width direction X, with the side edge guide 14a acting as the first side edge guide. The side edge guides 14a and 14b have regulating surfaces 14a1 and 14b1 as their inner surfaces in the sheet width direction X. For one side edge guide, the "inside" in the sheet width direction X is the side where the other side edge guide is positioned and where the sheet is loaded, and the "outside" in the sheet width direction X is the side opposite to the side where the other side edge guide is positioned. The regulating surfaces 14a1 and 14b1 are surfaces that extend in the feeding direction Y and rise substantially perpendicular to the feeding tray 5 when viewed in the feeding direction Y. The restricting surfaces 14a1 and 14b1 contact the edges (side edges of the sheets) of the sheets loaded on the feeding tray 5 in the sheet width direction X, thereby restricting the position of the sheets in the sheet width direction X.

[0036] The side end guides 14a and 14b are movable in the sheet width direction X relative to the feeding tray 5. The side end guides 14a and 14b are connected by an interlocking mechanism such as a rack and pinion mechanism, and move in conjunction with each other so that their distance from the central position X0 in the sheet width direction X is equal. The central position X0 is the reference position in the sheet width direction X of the sheet fed by the manual feeding unit 235.

[0037] One of the side edge guides 14a and 14b (the side edge guide 14a on the front side of the image forming apparatus 201) is provided with an operating knob 18, which serves as an operating part (gripping part) for moving the side edge guides 14a and 14b. By moving the side edge guides 14a and 14b to a position that matches the size of the sheet being used, the user can prevent the sheet from becoming skewed or misaligned.

[0038] The blower fans 15a and 15b are examples of blower fans (air blowing means, blowers) that provide air to help separate the sheets loaded on the supply tray 5. The blower fans 15a and 15b generate airflow by taking in outside air from an air intake provided on the bottom surface of the supply tray 5, for example. In this embodiment, the blower fans 15a and 15b are positioned below the mounting surface 5a of the supply tray 5. The blower fans 15a and 15b are fan motors in which a fan body that generates airflow by rotation and a motor that drives the fan body are integrated.

[0039] The side end guides 14a and 14b have outlets 16a and 16b for blowing air from the blower fans 15a and 15b onto the side edges of the sheets on the supply tray 5. The outlets 16a and 16b are openings formed in the restricting surfaces 14a1 and 14b1 of the side end guides 14a and 14b. The outlets 16a and 16b are also connected to the exhaust sections of the blower fans 15a and 15b via ducts (air passages) formed inside the side end guides 14a and 14b.

[0040] When the blower fans 15a and 15b are activated, air is blown out from the outlets 16a and 16b toward the inside in the sheet width direction X, as shown by the streamlines A1 and A2.

[0041] The opening heights of the air outlets 16a and 16b are set higher than the maximum sheet loading height in the supply tray 5. The maximum sheet loading height is indicated, for example, by attaching stickers indicating the maximum loading height to the regulating surfaces 14a1 and 14b1 of the side end guides 14a and 14b.

[0042] Furthermore, if the method of applying air blowing is changed depending on the type of sheet, the maximum stacking height for sheets that are subjected to air blowing (e.g., coated paper) may be set lower than the maximum stacking height for sheets that are not subjected to air blowing (e.g., plain paper). In addition, when coated paper is selected in the control unit 730, a message warning about the maximum stacking height may be displayed.

[0043] (Feeding operation of the manual feed unit) Next, the feeding operation in which the manual feed unit 235 feeds the sheets will be explained with reference to Figure 2. The user sets the sheets in the feed tray 5 in advance and inputs the setting information of the set sheets via the operation unit 730.

[0044] When the user presses the print execution button, the blower fans 15a and 15b activate and begin blowing air, and air is blown from the outlets 16a and 16b onto the side edges of the sheets. This air enters the gaps between the sheets, causing them to float and reducing the adhesion between them. As a result, the manual feed unit 235 can feed the sheets one by one while stably separating them, even when using sheets with a highly smooth surface, such as coated paper, which are prone to sticking together. The control unit 100 of the image forming apparatus 201 may also be configured to activate the blower fans 15a and 15b only when it determines, based on the sheet setting information, that separation by blowing air is necessary (for example, in the case of coated paper).

[0045] Subsequently, after a predetermined time has elapsed since the start of airflow from the blower fans 15a and 15b, the rotational drive of the pickup roller 502 and feed roller 503 is initiated, causing the roller holder to swing and the pickup roller 502 to move from the standby position to the feeding position. Then, the uppermost sheet that has come into contact with the pickup roller 502 is sent to the feed roller 503, where it is separated from the other sheets at the separation nip and further transported, and then sent to the registration roller pair 240 (Figure 1) by the transport roller pair 506. The subsequent flow of sheet transport and image formation is as described above. In addition, the sheet transport timing is monitored by the sheet sensor 505 (Figure 1) detecting the sheet between the feed roller 503 and the transport roller pair 506.

[0046] (Details of the air spray configuration) The details of the configuration for blowing air onto the sheet in Example 1 will be explained below using Figures 3 to 10.

[0047] Figure 3 is a schematic view of the manual feed unit 235 from above. Figure 4(a) is a cross-sectional view showing the IVA-IVA section of Figure 3. Figure 4(b) is a cross-sectional view showing the IVB-IVB section of Figure 3. Figure 5 is a cross-sectional view showing the VV section of Figure 3. Figure 6 is a schematic view showing the side edge guides 14a and 14b moved to their outermost position (the side edge position of the largest size sheet Sa that can be fed from the manual feed unit 235). Figure 7 is a schematic view showing the side edge guides 14a and 14b moved to their innermost position (the side edge position of the smallest size sheet Sb that can be fed from the manual feed unit 235). Figure 8 is a detailed view of the manual feed unit 235 from above. Figure 9 is a view of the top surface of the feed tray 5 as seen through in Figure 8. Figure 10 is a cross-sectional view showing the XX section of Figure 8.

[0048] As shown in Figures 4(a, b) and 5, the blower fans 15a and 15b are positioned below the mounting surface 5a of the feed tray 5. In other words, the blower fans 15a and 15b are positioned on the side opposite to the mounting surface 5a from the side on which the sheet is placed. This configuration makes it possible to save space in the manual feed unit 235 equipped with an air blowing configuration. That is, if the blower fan 15a were to be positioned above the mounting surface 5a, the blower fan would have to be positioned to avoid the mounting surface 5a. In this case, the blower fan would protrude beyond the outside of the feed tray 5 in the sheet width direction X, increasing the space occupied by the manual feed unit 235 and ultimately leading to a larger image forming apparatus.

[0049] In contrast, in this embodiment, the blower fans 15a and 15b are positioned using the space below the mounting surface 5a of the feed tray 5, thus saving space in the manual feed unit 235 and enabling miniaturization of the image forming apparatus. Furthermore, since the blower fans 15a and 15b do not protrude above the feed tray 5, access to the feed tray 5 is improved, enhancing usability and offering advantages in terms of noise reduction.

[0050] When viewed from above the feeding tray 5, it is preferable to position the blower fans 15a and 15b so that at least a portion of them overlaps with the mounting surface 5a of the feeding tray 5 (Figure 3). In the sheet width direction X, each blower fan 15a and 15b is positioned to overlap with the mounting surface 5a. In other words, the blower fan 15a is positioned so that at least a portion of its position in the sheet width direction X overlaps with the position of the mounting surface 5a in the sheet width direction X. Similarly, the blower fan 15b is positioned so that at least a portion of its position in the sheet width direction X overlaps with the position of the mounting surface 5a in the sheet width direction X. This further saves space. The mounting surface 5a (sheet loading area) of the feeding tray 5 is the area on the upper surface of the feeding tray 5 where the largest sheet Sa that can be fed from the manual feeding unit 235 is loaded. In other words, the mounting surface 5a of the feeding tray 5 is the sheet loading area (Figure 6) on which the sheet Sa is placed when the side edge guides 14a and 14b are extended to their furthest outward positions in the sheet width direction X. Therefore, the area (Figure 7) on which the sheet Sb is placed when the side edge guides 14a and 14b are narrowed to their furthest inward positions in the sheet width direction X is a part of the mounting surface 5a in this embodiment and is completely encompassed by the mounting surface 5a. To put it another way, even in the state shown in Figure 7, the mounting surface 5a of the feeding tray 5 is the area inside the width of the largest sheet Sa shown by the dashed line in Figure 7.

[0051] As shown in Figure 6, a portion of the blower fan 15a in the sheet width direction X may overlap with the position of the mounting surface 5a in the sheet width direction X, or the entire blower fan 15a in the sheet width direction X may overlap with the position of the mounting surface 5a in the sheet width direction X.

[0052] It is preferable to house the blower fans 15a and 15b within the housing of the feed tray 5. That is, it is preferable that the blower fans 15a and 15b are housed in the internal space of the feed tray 5 that extends between the mounting surface 5a (top surface) and the bottom surface 5b of the feed tray 5, as shown in Figure 10. With this configuration, since the blower fans 15a and 15b are not exposed to the outside, there are advantages such as improved safety, aesthetic appearance, and reduced noise. In addition, the feed tray 5 can be opened and closed relative to the main body 201A of the image forming apparatus 201 without worrying about interference between the blower fans 15a and 15b and the main body 201A. Therefore, compared to, for example, a case where space is secured to accommodate the blower fans 15a and 15b when the feed tray 5 is closed relative to the main body 201A, there are advantages such as miniaturization of the apparatus and increased design flexibility.

[0053] As shown in Figures 3, 6, and 7, the blower fan 15a is attached to a side edge guide 14a that is movable in the sheet width direction X relative to the supply tray 5, and moves together with the side edge guide 14a. Similarly, the blower fan 15b is attached to a side edge guide 14b that is movable in the sheet width direction X relative to the supply tray 5, and moves together with the side edge guide 14b. By configuring the blower fans 15a and 15b to move together with the side edge guides 14a and 14b, the configuration of the ducts (air passages) that guide the air from the blower fans 15a and 15b to the outlets 16a and 16b can be simplified.

[0054] An intake port is provided on the wall surface of the supply tray 5 facing the intake-side opening of the blower fans 15a, 15b (Figure 9). In this embodiment, an intake port 19a, 19b is provided on the bottom surface 5b of the supply tray 5, with a plurality of slits arranged in the sheet width direction X. The length of the intake ports 19a, 19b may be such that when the side end guides 14a, 14b move from one end of their range of motion to the other, at least a portion of the intake-side opening 15a2 (Figure 10) of the blower fans 15a, 15b faces the intake ports 19a, 19b. This prevents the pressure loss from increasing as the blower fans 15a, 15b move far away from the intake ports 19a, 19b. The length of the intake ports 19a, 19b in the sheet width direction X may be longer than the diameter of the intake-side opening 15a2 (Figure 10) of the blower fans 15a, 15b.

[0055] As shown in Figure 4(a), the front-facing fan 15a draws in air (outside air) from outside the supply tray 5 via the intake port 19a (streamline E1). A duct 141a is formed inside the side end guide 14a. The air exhausted from the fan 15a (streamline D1) is guided to the outlet 16a by the duct 141a. In this embodiment, the duct 141a extends in the supply direction Y inside the side end guide 14a, and the air is distributed by the duct 141a to two outlets 16a (a first outlet and a second outlet) (streamline B1). The air is then blown from the outlet 16a inward in the sheet width direction X towards the side edge of the sheet S (streamline A1; see also Figure 3).

[0056] As shown in Figure 4(b), the airflow path on the rear side is the same as on the front side, except that the position of the blower fan 15b is different. That is, the blower fan 15b takes in air (outside air) from outside the supply tray 5 via the intake port 19b (streamline E1). A duct 141b is formed inside the side end guide 14b. The air exhausted from the blower fan 15b (streamline D1) is guided to the outlet 16b by the duct 141b. In this embodiment, the duct 141b extends in the supply direction Y inside the side end guide 14b, and the air is distributed to the two outlets 16b by the duct 141b (streamlines B1, C1). The air is then blown from the outlet 16b inward in the sheet width direction X towards the side edge of the sheet S (streamline A2 in Figure 3).

[0057] As shown in Figure 5, when viewed in the supply direction Y, the exhaust direction of the blower fan 15a and the air outlet direction of the outlet 16a are arranged to be opposite with respect to the sheet width direction X. That is, the blower fan 15a is arranged to exhaust air outward with respect to the sheet width direction X (streamline F1). The outlet 16a is arranged to blow air inward with respect to the sheet width direction X (streamline A1). In this configuration, the blower fan 15a is provided integrally with the side end guide 14a, and the blower fan 15a is positioned by utilizing the space inside the side end guide 14a in the sheet width direction X. This configuration makes it possible to save space in the manual feeding section 235 with respect to the sheet width direction X. Furthermore, it is preferable that the entire rotating blade, which is the main body of the blower fan 15a, is located inside the sheet width direction X from the restricting surface 14a1 of the side end guide 14a.

[0058] Figure 5 illustrates the arrangement of the front-side blower fan 15a, but the arrangement for the rear-side blower fan 15b is similar, except that the positional relationship in the sheet width direction X is reversed. That is, when viewed in the supply direction Y, the exhaust direction of the blower fan 15b and the air outlet direction from the outlet 16b are arranged to be opposite with respect to the sheet width direction X (see Figure 3). This configuration makes it possible to save space in the manual feeding unit 235 in the sheet width direction X.

[0059] As shown in Figures 9 and 10, in this embodiment, sirocco fans, a type of centrifugal fan, are used as the blower fans 15a and 15b, and the rotation axes 15a1 and 15b1 of the rotating blades are arranged to intersect with the mounting surface 5a of the feed tray 5. Preferably, the rotation axes 15a1 and 15b1 are arranged to be approximately perpendicular to the mounting surface 5a (approximately parallel to the normal direction Z of the mounting surface 5a). This makes it possible to reduce the thickness of the feed tray 5.

[0060] A centrifugal fan is a fan that draws in air from one side of the axial direction of its rotating blades and exhausts it in a direction perpendicular to the axial direction (centrifugal direction). Examples include sirocco fans and turbo fans. Among centrifugal fans, sirocco fans are superior in that they balance quietness, durability, and the static pressure necessary for sheet separation, and a sirocco fan is used in this embodiment. However, it is also possible to use centrifugal fans other than sirocco fans or axial flow fans as blower fans.

[0061] Incidentally, as shown in Figure 5, the duct 141a penetrates the upper surface of the supply tray 5 from bottom to top so as to connect the blower fan 15a located below the mounting surface 5a of the supply tray 5 and the outlet 16a located above the mounting surface 5a. The same applies to the duct 141b on the rear side. Therefore, as shown in Figure 8, a notch 5d (slit, opening) is formed in the mounting surface 5a to allow the ducts 141a and 141b to move in the sheet width direction X as the side end guides 14a and 14b move. The position and shape of the notch 5d can be changed to match the ducts 141a and 141b. In addition, a notch is also formed in the mounting surface 5a near the interlocking mechanism M1, which will be described later, through which a part of the side end guides 14a and 14b penetrate vertically.

[0062] The configuration of the side end guides 14a, 14b and the blower fans 15a, 15b, and the positional relationship of the blower fans 15a, 15b will be explained. As shown in Figures 6 and 7, the pair of side end guides 14a, 14b move in conjunction with each other in the sheet width direction X.

[0063] As shown in Figure 9, the side end guides 14a and 14b are connected to each other inside the feed tray 5 by interlocking mechanisms M1 and M2. In this embodiment, a rack and pinion mechanism consisting of racks 143a and 143b and a pinion gear 142 is used as the interlocking mechanism M1. A rack and pinion mechanism consisting of racks 145a and 145b and a pinion gear 144 is used as the interlocking mechanism M2.

[0064] As shown in Figure 6, the blower fans 15a and 15b, which move together with the side end guides 14a and 14b, are positioned inward in the sheet width direction X relative to the side end guides 14a and 14b. This allows for miniaturization of the manual feeding unit 235 in the sheet width direction X.

[0065] In this embodiment, the positions of the blower fan 15a (first blower fan) and the blower fan 15b (second blower fan) are arranged differently in the supply direction Y. This makes it less likely for the blower fans 15a and 15b to interfere with each other even when the side edge guides 14a and 14b are moved in the sheet width direction X, and allows narrow sheets to be restricted by the side edge guides 14a and 14b.

[0066] In particular, as shown in Figure 7, when the side edge guides 14a and 14b are moved to a position that matches the smallest size sheet Sb, the positions of the blower fans 15a and 15b overlap when viewed in the feeding direction Y. In other words, when the first and second side edge guides are moved to their innermost positions in the sheet width direction, the first and second blower fans overlap when viewed in the feeding direction. This allows for effective use of the space inside the feeding tray 5 to accommodate narrower sheets.

[0067] Furthermore, as shown in Figure 7, when the side edge guides 14a and 14b are moved to a position that matches the smallest size sheet Sb, the front side edge guide 14a, when viewed from above, overlaps with the rear side blower fan 15b. Also, the rear side edge guide 14b overlaps with the front side blower fan 15a. In other words, when the first and second side edge guides are moved to their innermost positions in the sheet width direction, the first side edge guide and the second blower fan overlap, and the second side edge guide and the first blower fan overlap, when viewed from above. This allows for effective use of the space inside the supply tray 5 to accommodate narrower sheets.

[0068] As shown in Figures 6, 7, and 10, the blower fans 15a and 15b are guided by slide shafts 17a and 17b held by the feed tray 5. The slide shafts 17a and 17b are axial members extending in the sheet width direction X. The blower fan 15a has a fitting portion 15a3 that fits with the slide shaft 17a. The blower fan 15b has a fitting portion 15b3 that fits with the slide shaft 17b. As a result, the weight of the blower fans 15a and 15b is supported by the slide shafts 17a and 17b, improving the operability of the side end guides 14a and 14b.

[0069] The position of the operating knob 18 on the side end guide 14a in the feeding direction Y may be aligned with the position of the slide shaft 17a in the feeding direction Y. This reduces the rotational force applied to the side end guide 14a relative to the slide shaft 17a when the side end guide 14a is moved, resulting in smoother movement of the side end guide 14a and improved operability.

[0070] Incidentally, as shown in Figure 6, the rotation axis 15a1 of the front-side blower fan 15a is located near the outlet 16a, while the rotation axis 15b1 of the rear-side blower fan 15b is located upstream of the outlet 16b of the side end guide 14b in the supply direction Y. In this case, the blower fan 15b is positioned such that the exhaust port 15b2 is located downstream of the supply direction Y with respect to the rotation axis 15b1. This shortens the air passage from the exhaust port 15b2 to the outlet 16b, reducing pressure loss and allowing air to be efficiently blown onto the sheet.

[0071] As shown in Figures 4(a, b), a door 601, which is an opening and closing member for jamming the cassette feeding unit 230 (Figure 1), is provided below the manual feeding unit 235. The door 601 is rotatably supported by a hinge 602 on the main body 201A (Figure 1) of the image forming apparatus 201, and is rotatable about an axis extending in the sheet width direction X. The trajectory 603 in the figure is the trajectory traced by the tip of the door 601 (the end furthest from the hinge 602) when the door 601 is opened and closed.

[0072] In this embodiment, the bottom surface 5b of the feeding tray 5 has a tapered inclined portion 5c that approaches the mounting surface 5a as it moves downstream in the feeding direction Y (see also Figure 10). This allows the thick blower fans 15a and 15b to be housed inside the feeding tray 5 while avoiding interference with the door 601. In addition, as long as the arrangement avoids interference with the door 601, for example, the blower fan 15b may be positioned in a location that overlaps with the trajectory 603 when viewed in the sheet width direction X, but is different from the front end of the door 601 in the sheet width direction X.

[0073] Example 2 The manual feed unit 235 according to Embodiment 2 will be described with reference to Figures 11 and 12. Figure 11 is a schematic view of the manual feed unit 235 of this embodiment, seen from above. Figure 12 is a cross-sectional view taken along line XII-XII in Figure 11. Hereinafter, elements with reference numerals common to Embodiment 1 will have substantially the same configuration and operation as those described in Embodiment 1.

[0074] This embodiment differs from Embodiment 1 in that it uses relatively low-cost axial flow fans as the blower fans 25a and 25b. Furthermore, it differs from Embodiment 1 in that the blower fans 25a and 25b are positioned near the upstream end of the feed tray 5 in the feed direction Y, and their positions overlap when viewed in the sheet width direction X.

[0075] The blower fans 25a and 25b are positioned so that the axis of rotation of their rotating blades (propellers) intersects with the mounting surface 5a of the supply tray 5 (preferably, it is approximately parallel to the direction normal to the mounting surface 5a). As a result, the blower fans 25a and 25b draw in outside air from below the supply tray 5 (streamline E1) and exhaust it upward toward the ducts 141a and 141b (streamline D1). The air then passes through the inside of the ducts 141a and 141b and is blown onto the side edges of the sheet from the outlets 16a and 16b.

[0076] In this embodiment as well, both the blower fans 25a and 25b are positioned below the mounting surface 5a of the supply tray 5, which serves as the loading member. Therefore, this embodiment also makes it possible to save space in the configuration for blowing air onto the sheet.

[0077] Example 3 The manual feed unit 235 according to Embodiment 3 will be described with reference to Figures 13 and 14. Figure 13 is a schematic view of the manual feed unit 235 of this embodiment, seen from above. Figure 14 is a cross-sectional view taken along line XIV-XIV of Figure 13. Hereinafter, elements with the same reference numerals as those in Embodiment 1 will have substantially the same configuration and operation as those described in Embodiment 1.

[0078] In this embodiment, sirocco fans with relatively high airflow, quiet operation, and excellent durability are used as the blower fans 35a and 35b. Furthermore, the blower fans 35a and 35b are positioned near the upstream end of the supply tray 5 in the supply direction Y, and the position of the blower fans 35a and 35b when viewed in the sheet width direction X overlaps, which is different from Embodiment 1.

[0079] The blower fans 35a and 35b are positioned so that the axis of rotation of their rotating blades (propellers) intersects with the mounting surface 5a of the supply tray 5 (preferably, approximately parallel to the direction normal to the mounting surface 5a). The blower fans 35a and 35b draw in outside air from below the supply tray 5 (streamline E1) and exhaust it in a direction along the mounting surface 5a. The ducts 141a and 141b have a curved section Cv that guides the air exhausted from the blower fans 35a and 35b in a direction along the mounting surface 5a toward the upper part of the mounting surface 5a. The air guided by the curved section Cv (streamline D1) passes inside the ducts 141a and 141b and is blown onto the side edges of the sheet from the outlets 16a and 16b.

[0080] In this embodiment as well, both the blower fans 35a and 35b are positioned below the mounting surface 5a of the supply tray 5, which serves as the loading member. Therefore, this embodiment also makes it possible to save space in the configuration for blowing air onto the sheet.

[0081] Example 4 The manual feed unit 235 according to Embodiment 4 will be described with reference to Figure 15. Figure 15 is a schematic view of the manual feed unit 235 of this embodiment as seen from above. Hereinafter, elements with the same reference numerals as those in Embodiment 1 will have substantially the same configuration and operation as those described in Embodiment 1.

[0082] This embodiment differs from Embodiment 1 in that the blower fans 15a and 15b are arranged facing each other in the sheet width direction X. The cross-sectional view in section AA of Figure 15 is the same as in Figure 5 of Embodiment 1. In addition, in this embodiment, one air outlet 16a and 16b are provided on each side end guide 14a and 14b.

[0083] Even with an arrangement like that in this embodiment, it is possible to reduce the space required for the air-blowing configuration for the sheet.

[0084] Example 5 The manual feed unit 235 according to Example 5 will be described with reference to Figure 16. Figure 16 is a schematic diagram showing a cross-section of the manual feed unit 235 of this embodiment, cut by a plane perpendicular to the feeding direction Y. Hereafter, elements with the same reference numerals as in Example 1 will have substantially the same configuration and operation as those described in Example 1.

[0085] In this embodiment, an axial flow fan is used as the blower fan 25a, and the blower fan 25a is positioned such that the axis of rotation of the rotating blades (propeller) is in a direction along the sheet width direction X (a direction approximately perpendicular to the restricting surface 14a1 of the side end guide 14a).

[0086] The blower fan 25a takes in air from the inside in the sheet width direction X (streamline D1) and exhausts it outwards in the sheet width direction X (streamline B1). The air from the blower fan 25a passes through the inside of the duct 141a and is blown onto the side edge of the sheet from the outlet 16a (streamline A1). Therefore, the exhaust direction of the blower fan 25a and the blowing direction of the air from the outlet 16a are opposite with respect to the sheet width direction X. Thus, this configuration also makes it possible to save space in the sheet width direction X.

[0087] According to this embodiment, the width occupied by the blower fan in the sheet width direction X can be reduced compared to the case where the blower fan is positioned so that its rotation axis is perpendicular to the mounting surface 5a of the supply tray 5. Therefore, the side end guides 14a and 14b can be brought closer to the sheet width direction X to accommodate even narrower sheets.

[0088] In this embodiment as well, the blower fan 25a is positioned below the mounting surface 5a of the supply tray 5, which serves as the loading member. Therefore, this embodiment also makes it possible to save space in the configuration for blowing air onto the sheet.

[0089] Although Figure 16 shows one side end guide 14a and blower fan 25a, a blower fan can also be arranged in a similar configuration on the other side end guide 14b.

[0090] Example 6 The manual feed unit 235 according to Example 7 will be described with reference to Figure 17. Figure 17 is a schematic diagram showing a cross-section of the manual feed unit 235 of this embodiment, cut by a plane perpendicular to the feeding direction Y. Hereafter, elements with the same reference numerals as in Example 1 will have substantially the same configuration and operation as those described in Example 1.

[0091] In this embodiment, a sirocco fan is used as the blower fan 35a, and the position of the blower fan 35a is fixed relative to the supply tray 5. The exhaust port of the blower fan 35a is connected to a duct 141a provided on the side end guide 14a via an expandable duct 36a that can expand and contract in the sheet width direction X.

[0092] The blower fan 35a takes in air from below (streamline D1) and exhausts it outwards in the sheet width direction X. The air from the blower fan 35a passes through the inside of the expandable duct 36a and duct 141a (streamline B1) and is blown onto the side edge of the sheet from the outlet 16a (streamline A1). Therefore, the exhaust direction of the blower fan 35a and the blowing direction of the air from the outlet 16a are opposite with respect to the sheet width direction X. Thus, this configuration also makes it possible to save space in the sheet width direction X.

[0093] Furthermore, in this embodiment, there is no need to move the blower fan 35a, which is an electrical component and a heavy object, together with the side end guide 14a. This eliminates the need to leave a margin for movement in the length of the power lines and signal lines to the blower fan 35a, and simplifies the wiring route. In addition, since there is no need to move a heavy object, the operating force required to move the side end guide 14a is reduced.

[0094] Alternatively, an axial fan may be fixed to the supply tray 5 instead of a sirocco fan.

[0095] Other embodiments In each of the embodiments described above, two air outlets 16a are provided on one side end guide 14a. The airflow from each air outlet 16a may be equal, or the airflow from one may be stronger than the other. Furthermore, the airflow may be turned ON / OFF depending on the type and size of the sheet. For example, the blower fan may be activated and the airflow turned ON only when the sheet size is greater than or equal to a predetermined size. The number of air outlets 16a may be one or three or more per side end guide 14a.

[0096] In the embodiments described above, a configuration was illustrated in which a blower fan is provided for each of the pair of side end guides 14a and 14b. However, the configuration is not limited to this, and a blower fan may be provided for only one of the side end guides.

[0097] In the embodiments described above, the mounting surface 5a of the feeding tray 5 does not move up or down, and the pickup roller 502 moves up or down (a so-called lifterless configuration) was illustrated as an example. However, a configuration in which the loading member that supports the sheet moves up or down is also possible. For example, in the cassette 1 (Figure 1), a support plate (middle plate) that can swing relative to the bottom of the cassette 1 and a lifter plate that moves the support plate up or down may be arranged. Furthermore, in a sheet feeding device equipped with a larger storage capacity, a lifter mechanism may be used that moves a support plate suspended from a wire up or down vertically by winding and unwinding the wire.

[0098] Furthermore, the embodiments described above primarily described manual sheet feeding devices provided on the side of image forming machines used in offices. However, the technology may also be applied to cassette feeding units 230 (Figure 1). In addition, the technology may be applied to manual sheet feeding devices or sheet feeding devices (optional feeders) used in larger commercial image forming machines, either as part of the image forming machine itself. [Explanation of symbols]

[0099] 5...Tray (feed tray) / 5a...Mounting surface / 14a, 14b...Side edge guide / 15a, 15b...Blower fan / 16a, 16b...Air outlet / 201A...Device body / 201B...Image forming means (image forming unit) / 502...Feeding means (pickup roller)

Claims

1. Image forming means for forming an image on a sheet, A tray having a mounting surface on which a sheet is placed is provided on the main body of the apparatus that houses the image forming means, A feeding means for feeding the sheet placed on the mounting surface toward the image forming means, With respect to the sheet width direction perpendicular to the sheet feeding direction by the aforementioned feeding means, a side edge restricting member restricts the side edges of the sheets stacked on the aforementioned surface, A fan attached to the tray generates airflow that is blown towards the side edge of the sheet in the sheet width direction, Equipped with, The blower fan is positioned on the opposite side of the mounting surface from the side on which the sheet is placed, and is positioned such that the position of the blower fan in the sheet width direction coincides with the position of the tray in the sheet width direction. The blower fan moves in the sheet width direction together with the side end restricting member. An image forming apparatus characterized by comprising:

2. When viewed in a direction perpendicular to the aforementioned mounting surface of the tray, the blower fan overlaps with the tray. The image forming apparatus according to feature 1.

3. The aforementioned blower fan is housed in the internal space of the tray that extends between the aforementioned mounting surface and the bottom surface of the tray. The image forming apparatus according to feature 1.

4. The side edge restricting member has an outlet that blows air from the blower fan onto the side edge of the sheet stacked on the aforementioned surface, The image forming apparatus according to feature 1.

5. The aforementioned blower fan is positioned such that its exhaust direction faces outward with respect to the sheet width direction. The air outlet is positioned such that the direction of air discharge is directed inward with respect to the sheet width direction. The image forming apparatus according to feature 4.

6. The blower fan is a centrifugal fan having rotating blades, which draws in air from one side in the axial direction of the rotating blades and exhausts air in a direction perpendicular to the axial direction, and is positioned such that the axis of rotation of the rotating blades intersects the aforementioned mounting surface. The image forming apparatus according to feature 5.

7. The side edge restricting member has a restricting surface that faces the side edge of the sheet in the sheet width direction, The entire rotating blade is located inward in the sheet width direction from the regulating surface. The image forming apparatus according to feature 6.

8. The aforementioned side end restricting member is designated as the first side end restricting member, and the aforementioned blower fan is designated as the first blower fan. A second side end restricting member is positioned on the opposite side of the first side end restricting member with respect to the sheet width direction and moves in the sheet width direction in conjunction with the first side end restricting member, A second blower fan that moves integrally with the second side end restricting member in the width direction of the sheet, and is configured to blow air onto the sheet through an outlet provided on the second side end restricting member, It also has, The image forming apparatus according to feature 4.

9. The position of the first blower fan and the position of the second blower fan are different in the aforementioned supply direction. The image forming apparatus according to feature 8.

10. With the first side end restricting member and the second side end restricting member moved to their innermost positions in the sheet width direction, the first blower fan and the second blower fan overlap when viewed in the supply direction. The image forming apparatus according to feature 9.

11. When the first side end restricting member and the second side end restricting member are moved to their innermost positions in the sheet width direction, when viewed from above, the first side end restricting member and the second blower fan overlap, and the second side end restricting member and the first blower fan overlap. The image forming apparatus according to feature 9.

12. The side end restricting member has a duct that guides air from the blower fan to the outlet. The tray is provided with an opening that penetrates from the lower to the upper side of the aforementioned mounting surface, and which allows the duct to move when the side end restricting member moves in the sheet width direction. The image forming apparatus according to feature 4.

13. The blower fan is configured to take in outside air through an air intake provided on the bottom surface of the tray. The air intake port extends in the sheet width direction such that when the side end restricting member moves from one end to the other of the side end restricting member's range of movement, at least a portion of the opening on the intake side of the blower fan faces the air intake port. The image forming apparatus according to feature 4.

14. The side end restricting member has a second outlet located away from the outlet in the supply direction, and a duct extending in the supply direction to guide air from the blower fan to the outlet and the second outlet. The image forming apparatus according to feature 4.

15. The blower fan is positioned upstream of the side end restricting member in the supply direction. The image forming apparatus according to feature 4.

16. The aforementioned blower fan is a sirocco fan. The image forming apparatus according to feature 1.

17. The aforementioned blower fan is an axial flow fan. The image forming apparatus according to feature 1.

18. The position of at least a portion of the blower fan in the sheet width direction coincides with the position of the mounting surface described above in the sheet width direction, The image forming apparatus according to any one of claims 1 to 17.

19. When viewed in a direction perpendicular to the aforementioned mounting surface of the tray, at least a portion of the blower fan overlaps with the aforementioned mounting surface. The image forming apparatus according to any one of claims 1 to 17.

20. At least a portion of the range in which the blower fan moves together with the side end restricting member in the sheet width direction coincides with the position of the mounting surface described above in the sheet width direction, The image forming apparatus according to any one of claims 1 to 17.

21. In each of the states in which the side edge restricting member is moved to the outermost position in the sheet width direction and in which the side edge restricting member is moved to the innermost position in the sheet width direction, the position of the blower fan in the sheet width direction and the position of the mounting surface described above in the sheet width direction coincide. The image forming apparatus according to any one of claims 1 to 17.

22. The tray is rotatably mounted relative to the main body of the device. The image forming apparatus according to any one of claims 1 to 17.

23. The blower fan moves integrally with the side edge restricting member in the sheet width direction. The image forming apparatus according to any one of claims 1 to 17.

Images