JP5217911B2 - Sheet feeding apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet feeding device that separates and feeds stacked sheets, and an image forming apparatus that forms an image on a sheet fed from the sheet feeding device.

  In Patent Document 1, air is blown to the end of stacked sheets so that air is sent between a plurality of stacked sheets, thereby making it easy to separate closely attached sheets and preventing double feeding of sheets. Is disclosed.

  Patent Document 2 discloses that the sheet is heated by a heater (heat generating portion) to release the sheet and the sheet is dehumidified to prevent double feeding of the sheet.

Japanese Patent No. 4095656 JP 2006-27796 A

  However, in the technique of Patent Document 1, in the case of a type of sheet having a strong inter-sheet adhesion, it is difficult to send air between the sheets. It may cause sending and non-feeding.

  In the technology of Patent Document 2, in the case of a type of sheet having a strong inter-sheet adhesion, even if the sheet is dehumidified, the adhesion of the sheet may not be released, resulting in double feeding or non-feeding.

  The present invention has been made in view of the above, and relates to a sheet feeding apparatus capable of reliably separating and feeding sheets regardless of the type of sheet, and an image forming apparatus including the sheet feeding apparatus. The purpose is to provide.

In order to solve the above-described problem, the invention described in claim 1 includes a sheet stacking tray on which a plurality of sheets are stacked, a pickup roller that feeds a sheet in contact with the uppermost stacked sheet, and a stacked sheet A sheet edge regulating member that regulates the edge position, a blower opening that is provided on the sheet edge regulating member and blows air toward the stacked sheet edge, and a vicinity of the uppermost sheet edge of the stacked sheet provided on the sheet edge regulating member A sheet pressing member that presses the uppermost sheet from above and a designating unit that specifies the type of the sheet. The sheet pressing member is provided with a heat generating portion, and the control for controlling the heat generation amount of the heat generating portion is provided. And the control unit controls the amount of heat generated by the heat generating unit in accordance with the type of the sheet specified by the specifying unit.

  The invention according to claim 2 is the invention according to claim 1, wherein the designation means designates the coating sheet and the other sheets, and the control unit only when the coating sheet is designated. The heat generating part generates heat.

  The invention according to claim 3 is the invention according to claim 1, wherein the designation means designates the type of the sheet by the smoothness of the sheet surface, and the control unit has a high smoothness of the designated sheet surface. The heat generation amount of the heat generating part is increased.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the designating means designates the type of the sheet according to the thickness of the sheet. It is characterized by increasing the calorific value.

  According to a fifth aspect of the present invention, in the first aspect of the invention, the designating means designates the type of the sheet by the inter-sheet friction coefficient, and the control unit generates heat as the designated inter-sheet friction coefficient increases. The heat generation amount of the part is increased.

  The invention described in claim 6 includes the sheet feeding device according to any one of claims 1 to 5, and forms a read image on a sheet fed by the sheet feeding device. The image forming apparatus is characterized.

  According to the present invention, since the heat generating portion is provided in the sheet pressing member that regulates the sheet floating, the uppermost sheet T pressed by the sheet pressing member is curled by heat and air is blown to the curled portion. Thus, air can be easily blown between the sheets, and even a sheet having a strong inter-sheet adhesion can be released. Therefore, regardless of the type of sheet, the sheet can be reliably separated and fed.

  Since the sheet holding member is only provided with a heat generating portion to curl the sheet at the uppermost position and is not dehumidified by heating as in Patent Document 2, the amount of heat generated can be reduced, thereby reducing power consumption. Can do.

  Since the heat generation amount of the heat generating portion can be changed according to the type of sheet, for example, a sheet having a stronger inter-sheet adhesion can be sufficiently curled with a higher calorific value, and a sheet having a lower inter-sheet adhesion. The amount of heat generated can be reduced to reduce power consumption. Note that “reducing the amount of heat generation” includes making the amount of heat generation zero. “Controlling the amount of heat generated by the heat generating portion” means controlling the output of the heat generating portion, the heat generation time, and the like.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view showing an air ejection port and its peripheral part of the sheet feeding apparatus according to the first embodiment, FIG. 2 is a side view showing an upper part of a sheet end regulating member, and FIG. 3 is a sheet. 4 is a side view showing the positional relationship between the end regulating member and the sheet, FIG. 4 is a perspective view showing the sheet feeding device, and FIG. 5 is a perspective view of the sheet feeding device viewed from a direction different from FIG. 6 is a front view showing the operation of the sheet feeding device, FIG. 7 is a block diagram showing the relationship among the operation panel, the main body control unit, and the control unit, and FIG. 8 uses the sheet feeding device. 1 is a side view illustrating a schematic configuration of an image forming apparatus.

  As shown in FIG. 8, the image forming apparatus 1 according to the first embodiment includes an image forming apparatus main body 2 and one side surface of the image forming apparatus main body 2 connected to the image forming apparatus main body 2 as a recording medium. And a sheet feeding device 5 for feeding the sheet (paper). The image forming apparatus main body 2 is, for example, a copying machine.

  As shown in FIG. 7, the image forming apparatus main body 2 is provided with an operation panel (designating means) 31 and a main body control unit 3, and the sheet feeding apparatus 5 is provided with a control unit 29. An operation signal from the operation panel 31 is transmitted to the control unit 29 via the main body control unit 3.

  As shown in FIGS. 4 and 5, the sheet feeding device 5 includes a sheet feeding tray (sheet storage unit) 8 having a bottom plate 6 on which a sheet bundle (sheet bundle) is stacked, and the uppermost sheet of the sheet bundle. A sheet feeding unit (sheet feeding means) 9 for taking out the sheets one by one and feeding them to the image forming apparatus main body 2 side is provided.

  The sheet feeding unit 9 is provided in the sheet feeding apparatus main body, and a sheet feeding roller (pickup roller) 11, a separation roller 12a, and a return roller 12b are arranged in the sheet feeding unit 9. These rollers 11, 12a, 12b are driven to rotate at respective preset paper feed timings.

  Also, in the sheet tray 8, side fences (sheet end regulating members on both sides) 13, 13 for guiding side surfaces in the width direction (direction perpendicular to the sheet feeding direction) of the sheet bundle stacked on the bottom plate 6 are opposed to each other. An end fence (rear sheet end regulating member) 14 for pressing the rear end surface is provided behind the sheet bundle.

  The upper limit of the sheet bundle is detected by a sensor 15 composed of a photo interrupter. The sensor 15 detects the sheet feeding position, so that the sheet feeding position does not always vary even when the remaining amount of sheets is low. The sheet feeding position is controlled by moving 6 up and down by a lifting motor M. In this way, in order to keep the paper feed separation condition constant, the sheet upper limit position is always optimized so that the paper feed position is always constant even when the sheet stacking amount increases or decreases.

  The actuator 16 (see FIG. 5) for operating the sensor 15 is connected to the sheet feeding roller 11 and the separation roller 12a, and the filler disposed at the end of the actuator 16 shields the sensor 15 from light. Thus, the upper limit of the sheet is always detected, and the position of the sheet feeding roller 11 is kept constant with respect to the uppermost sheet T. Further, even if the bottom plate 6 rises with a decrease in the amount of sheets (sheets) loaded, this position detection is performed by the actuator 16.

  The sheet feeding tray 8 is configured to be detachable from the sheet feeding apparatus main body. When a user sets a sheet on the sheet feeding tray 8, the sheet feeding tray 8 is pulled out from the sheet feeding apparatus main body.

  The left and right side fences 13 and 13 and the end fence 14 are movable, and move according to the size of the sheet to be stored.

  A blower fan 20 is attached to the outside of each side fence 13, 13, and an air outlet (air blowing port) 21 through which the air generated by the blower fan 20 is ejected is an inner side surface (left and right side fences 13, 13 is opened at the upper part of the opposing surface. As shown in FIG. 3, the air ejection port 21 is disposed at a position where the height of the upper end edge 22 a is lower than the sheet passing path P of the sheet fed by the sheet feeding unit 9, and in the sheet passing path P. Open along.

  As shown in FIG. 2, in the side fence 13, two ejection nozzles 25 a and 25 b are arranged side by side in the sheet feeding direction at the air ejection port 21, and the first ejection nozzle 25 a The second ejection nozzle 25b is arranged in a vertical direction along the lower edge 22b of the mouth 21, and is disposed in the vertical direction of the air ejection nozzle 21, and has a longer vertical dimension than the first ejection nozzle 25a. It is.

  A sheet presser (presser member) 23 that presses the uppermost sheet T is provided above the air jet port 21. As shown in FIGS. 1 and 2, the sheet presser 23 has a plate shape, and is arranged to be inclined in the vertical direction so that the lower end protrudes from the side fence 13 toward the sheet side. The lateral width of the sheet presser 23 (the dimension along the sheet feeding direction) is substantially the same as the lateral width of the air ejection port 21. Further, the sheet presser 23 is positioned with a gap between the lower end and the uppermost sheet T.

  The sheet presser 23 includes a heater (heat generating portion) 27, and the sheet presser 23 is heated by energizing the heater 27. The heater 27 is a resistor such as linear or plate-like tungsten or carbon fiber.

  As shown in FIG. 7, the heater 27 and the blower fan 20 are connected to a control unit 29, and the control unit 29 is connected to an operation panel 31, and the control unit 29 receives an operation signal from the operation panel 31. The amount of heat generated by the heater (heating unit) 27 and the drive of the blower fan 20 are controlled.

  The configuration of the control unit 29 will be described. The receiving unit 35 receives an operation signal from the operation panel 31. The determination unit 37 determines the situation based on information from the reception unit 35. The heat generation necessity determining unit 39 determines whether the heater 27 needs to generate heat according to the determination of the determination unit 37. The heat generation amount determination unit 41 determines the output of the heater 27 after the heat generation necessity determination unit 39 determines. The processing unit 43 executes processing in accordance with the determination of the determination unit 37, the determination of the necessity of heat generation determination unit 39, and the determination of the heat generation amount determination unit 41. The transmission unit 45 transmits the processing content of the processing unit 43 to the heater 27 and the blower fan 20.

  In the operation panel 31, the sheet type is displayed on the display unit 33. When the sheet type is selected by touching the sheet type display unit 33, the blower fan 20 and the heater 27 are driven according to the sheet type. It has become. When “plain paper” (sheet other than coated paper) is selected, only the blower fan 20 is driven. “Coated paper” refers to paper whose surface is coated with a paint to enhance aesthetics and smoothness. When “coated paper A” or “coated paper B” is selected, the blower fan 20 and the heater 27 are driven. Coated paper A is mat-coated paper and has a strong inter-paper adhesion compared to plain paper, and coated paper B is a gloss-coated paper and has a strong inter-paper adhesion compared to coated paper A. When “coated paper A” is selected, the output of the heater 27 is set to, for example, 10 W (watts), and when “coated paper B” is selected, the output of the heater 27 is set to, for example, 30 W. When “coated paper B” is selected, the output of the heater 27 is increased as compared with the case where “coated paper A” is selected as described above, and “coated paper A” is selected. The output of the blower fan 20 may be increased as compared with the case where it is performed.

  In the first embodiment, the air ejection port 21 and the sheet presser 23 are provided in each of the left and right side fences 13.

  Next, functions and effects of the sheet feeding device 1 according to the first embodiment will be described. After the sheet feed tray 8 is inserted into the sheet feeder main body, the bottom plate 6 on which sheets are stacked continues to rise until the actuator 16 detects the upper limit.

  When “coated paper A” is selected as the sheet type on the operation panel 31, the determination unit 37 determines that it is the coated paper A, the heat generation necessity determination unit 39 determines that heat generation is required, and the heat generation amount. The determination part 41 determines the output of the heater 27 to 10W. Receiving this, the processing unit 43 sets the output of the heater 27 to 10 W.

  As shown in FIG. 1, the blower fan 20 is driven to blow air from the nozzles 25a and 25b toward the end of the stacked sheets.

  As shown in FIG. 1, the sheet T at the uppermost position of the stacked sheets is floated by the ejected air and comes into contact with the sheet presser 23, and the uppermost sheet T is prevented from being blown up by the sheet presser 23.

  The uppermost sheet T abuts on the sheet presser 23, but the curl is generated by the heat of the heater 27 provided on the sheet presser 23. Then, since air further enters the gap where the sheet T is curled, the sheet (coated paper A) can be released from contact and the sheet can be effectively removed.

  The sheet whose contact has been released is fed between the separation roller 12a and the return roller 12b by the sheet feeding roller 11, and only the uppermost sheet T is reliably separated and fed.

  When the determination unit 37 determines that the feeding of the desired number of sheets has been completed, the processing unit 43 ends the heat generation of the heater 27 and the control of the heater 27 ends.

  When “Coated paper B” is selected as the sheet type on the operation panel 31, the determination unit 37 determines that the paper is the coated paper B, and the heat generation necessity determination unit 39 determines that heat generation is necessary, and heat generation. The amount determination unit 41 determines the output to be 30W. Receiving this, the processing unit 43 sets the output of the heater 27 to 30 W. Thereby, the strongly adhered sheet (coated paper B) can be sufficiently curled, air can be sufficiently fed, and the adhesion can be released.

  When “plain paper” is selected as the sheet type on the operation panel 31, the determination unit 37 determines that the sheet is plain paper, the heat generation necessity determination unit 39 determines that heat generation is not required, and the heater 27 is controlled. finish.

  According to the first embodiment, since the heater (heat generating portion) 27 is provided in the sheet presser (sheet presser member) 23 that regulates the sheet floating, the uppermost sheet T pressed by the sheet presser 23 is heated. Therefore, air can be blown easily between the sheets, and even the sheet having a strong adhesion between sheets can be released. Therefore, regardless of the type of sheet, the sheet can be reliably separated and fed.

  Since the heater 27 is provided on the sheet presser 23 to curl the sheet at the uppermost position and not dehumidified by heating as in Patent Document 2, the amount of heat generated is small, so the power consumption can be reduced. Can do.

  A sheet with stronger adhesion between sheets can be curled sufficiently by increasing the output of the heater 27 (increasing the amount of heat generation), and a sheet with weak adhesion between sheets can have a smaller output of the heater 27 (less heat generation). ), Power consumption can be reduced.

  Since the heater 27 is energized only when the coated paper is designated, the coated paper having a strong adhesion between sheets can be curled, and the plain paper having a low adhesion between sheets and a low necessity for heating is heated. Can be prevented.

  Since the output of the heater 27 with respect to the coated paper B, which has a stronger inter-sheet adhesion than the coated paper A, is increased, the coated paper B can be sufficiently curled, and there is sufficient air between the coated paper B. Can be sent to.

  Other embodiments of the present invention will be described below. In the following description, parts having the same operational effects as those of the first embodiment described above are denoted by the same reference numerals, and the parts thereof are described. Detailed description will be omitted, and the following description will mainly focus on differences from the first embodiment described above. A second embodiment will be described with reference to FIG. FIG. 9 is a block diagram showing the relationship among the operation panel, the main body control unit, and the control unit. In the second embodiment, as shown in FIG. 9, the type of sheet is designated by the smoothness of the sheet on the operation panel 31. The display unit 33 displays three modes “high”, “medium”, and “low” in descending order of sheet smoothness. “Medium” is the smoothness of plain paper, “Low” is the smoothness of a sheet with a rougher surface than plain paper, and “High” is the smoothness of a sheet with a smoother surface than plain paper. In general, the higher the smoothness of a sheet, the greater the adhesion between sheets. The smoothness of the sheet is determined by touching the sheet and determining whether the surface is rough compared to plain paper.

  When a user feeds a sheet other than plain paper, the user touches the sheet to determine whether the surface is rougher than plain paper. When it is determined that the surface is rougher than the plain paper, the “low” of the display unit 33 is touched. At this time, the determination unit 37 determines that the sheet smoothness is low, the heat generation necessity determination unit 39 determines that heat generation is not necessary, and the control of the heater 27 ends.

  When the user determines that the surface is not rough (smooth) than the plain paper, the user touches “high” on the display unit 33. At this time, the determination unit 37 determines that the sheet smoothness is high, the heat generation necessity determination unit 39 determines that heat generation is necessary, and the heat generation amount determination unit 41 determines the output of the heater 27 to 30 W, for example. Receiving this, the processing unit 43 sets the output of the heater 27 to 30 W.

  The user touches “middle” of the display unit 33 when feeding plain paper. At this time, the determination unit 37 determines that the sheet smoothness is medium, the heat generation necessity determination unit 39 determines that heat generation is necessary, and the heat generation amount determination unit 41 determines the output of the heater 27 to 20 W, for example. . Receiving this, the processing unit 43 sets the output of the heater 27 to 20 W.

  According to the second embodiment, the higher the sheet smoothness, the greater the output of the heater 27. Therefore, a sheet with high sheet smoothness and strong inter-sheet adhesion can be sufficiently curled and the smoothness is low. It is possible to reduce the output of the heater 27 with respect to a sheet having weak adhesion between sheets.

  A third embodiment will be described with reference to FIG. FIG. 10 is a block diagram showing the relationship among the operation panel, the main body control unit, and the control unit. In the third embodiment, as shown in FIG. 10, the type of sheet is designated by the thickness of the sheet on the operation panel 31. The display unit 33 displays three modes of “thick”, “medium”, and “thin” in order of increasing sheet thickness. “Thick” corresponds to, for example, drawing paper, “medium” corresponds to plain paper, and “thin” corresponds to, for example, tracing paper. The thickness of the sheet is determined based on whether the sheet is touched or thicker than plain paper.

  In general, the thicker the sheet, the greater the amount of heat generated by the heater 27 in order to curl the sheet. Therefore, the output of the heater 27 is increased as the thickness of the sheet increases. The control of the control unit 29 is the same as that in the second embodiment.

  According to the third embodiment, since the output of the heater 27 is increased as the thickness of the sheet is increased, the sheet can be sufficiently curled regardless of the thickness of the sheet, and the output of the heater 27 is decreased as the thickness of the sheet is decreased. Since the size is reduced, power consumption can be reduced.

  A fourth embodiment will be described with reference to FIG. FIG. 11 is a block diagram showing the relationship among the operation panel, the main body control unit, and the control unit. In the fourth embodiment, as shown in FIG. 11, the type of sheet is designated by the friction coefficient between sheets on the operation panel 31. The display unit 33 displays three modes of “large”, “medium”, and “small” in descending order of the friction coefficient between sheets. “Large” corresponds to, for example, OHP paper, “medium” corresponds to plain paper, and “small” corresponds to, for example, tracing paper. Generally, the greater the friction coefficient between sheets, the stronger the adhesion between sheets. The control of the control unit 29 is the same as that in the second embodiment.

  Since the output of the heater 27 increases as the friction coefficient between sheets increases, a sheet having a large friction coefficient between sheets and a strong adhesion between sheets can be sufficiently curled, and the friction coefficient between sheets is small and the adhesion between sheets is weak. The amount of heat generated by the heater 27 with respect to the sheet can be reduced.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. For example, a plurality of air outlets 21 and sheet pressers 23 may be provided side by side on one side fence 13.

  In addition to the side fences 13 and 13, the air outlet 21 and the sheet presser 23 may be provided on the end fence 14, or may be provided on one side fence 13 and the end fence 14.

  The image forming apparatus 1 is not limited to a copying machine, but may be a printer, a fax machine, or the like.

  Although the output of the heater 27 is changed according to the type of sheet, the output of the heater 27 is kept constant, the heater 27 is intermittently heated, and the heat generation time is changed according to the sheet type, or the interval between the heat generation times (heat generation) You may change the time between. Specifically, a timer is provided in the control unit 29, and the heat generation time of the heater 27 is increased by increasing the heat generation time of a sheet having a larger interval between sheets with a constant interval between heat generation times or a thicker sheet. The interval between the heat generation times is shortened as the sheet has a greater time and the sheet adhesion strength is greater or the sheet thickness is greater. As a result, a sheet having a greater adhesion between sheets or a thicker sheet can be sufficiently curled and the heater 27 is intermittently heated, so that power consumption can be reduced.

  In the modified example, the heater 27 is intermittently heated using the timer 44, but may be intermittently generated using a thermostat (temperature controller).

  In the first embodiment, instead of displaying the coated paper A and the coated paper B on the operation panel 31, film A and film paper B may be used.

It is a front view which shows the air ejection opening of the sheet feeding apparatus which concerns on 1st Embodiment, and its peripheral part. It is a side view showing the upper part of a sheet end regulating member. It is a side view which shows the positional relationship of a sheet | seat end regulation member and a sheet | seat. It is a perspective view which shows a sheet feeding apparatus. FIG. 5 is a perspective view of the sheet feeding device viewed from a direction different from that in FIG. 4. It is a front view showing an operation of the sheet feeding device. It is a block diagram which shows the relationship between an operation panel, a main body control part, and a control part. 1 is a side view illustrating a schematic configuration of an image forming apparatus using a sheet feeding device. It is a block diagram which shows the relationship between the operation panel in 2nd Embodiment, a main body control part, and a control part. It is a block diagram which shows the relationship between the operation panel in 3rd Embodiment, a main body control part, and a control part. It is a block diagram which shows the relationship between the operation panel in 4th Embodiment, a main body control part, and a control part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 5 Sheet feeding apparatus 11 Sheet feeding roller (pickup roller)
13 Side fence (Sheet edge regulating member on both sides)
14 End fence (rear sheet end regulating member)
21 Air outlet (air outlet)
23 Sheet presser (presser member)
27 Heater (heat generating part)
29 Control unit 31 Operation panel (designating means)
T top sheet

Claims (6)

Provided on a sheet stacking tray that stacks multiple sheets, a pickup roller that feeds the sheet in contact with the top stacked sheet, a sheet end regulating member that regulates the position of the stacked sheet end, and a sheet end regulating member A sheet outlet member that blows air toward the end of the stacked sheet, a sheet pressing member that is provided in the sheet end regulating member and is in contact with the vicinity of the uppermost sheet end of the stacked sheet and presses the uppermost sheet from above. The sheet pressing member is provided with a heat generating part, and has a control part for controlling the amount of heat generated by the heat generating part. The control part determines the sheet type specified by the specifying means. A sheet feeding device that controls the amount of heat generated by the heat generating unit accordingly.   2. The sheet feeding device according to claim 1, wherein the designating unit designates a coated sheet and other sheets, and the control unit causes the heat generating unit to generate heat only when the coated sheet is designated. Feeding device.   The designating means designates the sheet type according to the smoothness of the sheet surface, and the control unit increases the amount of heat generated by the heat generating part as the designated sheet surface has a higher smoothness. The sheet feeding apparatus according to the description.   2. The sheet feeding device according to claim 1, wherein the designating unit designates the type of the sheet by the thickness of the sheet, and the control unit increases the amount of heat generated by the heat generating unit as the designated sheet thickness increases. Feeding device.   2. The specification means according to claim 1, wherein the designation means designates the type of the sheet by means of the inter-sheet friction coefficient, and the control unit increases the amount of heat generated by the heat generating unit as the designated inter-sheet friction coefficient increases. Sheet feeding device.   An image forming apparatus comprising the sheet feeding device according to claim 1, and forming a read image on a sheet fed by the sheet feeding device.

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