JP2013028411A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of preventing the consumption of excessive electric power and deterioration in productivity.SOLUTION: When turning on a power source or when releasing a standby power source mode, when a paper face detecting sensor 503 for detecting that a sheet reaches a feedable position of the sheet by a pickup roller 105 by a rise in a sheet stacking plate by a lifting part does not detect the sheet, initial operation is performed, and when the paper face detecting sensor 503 detects the sheet, control is performed so as to eliminate a part or the whole of the initial operation.

Description

  The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus that has a standby power supply mode in which an image forming apparatus main body is in a standby state with low power consumption, and that performs a predetermined initial operation when sheet feeding is started.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer that applies electrophotographic technology, a toner image is formed on an image carrier such as a photosensitive drum provided in an image forming unit, and the toner image is transferred to a sheet. After that, the image is fixed on the sheet by fixing means. Such an image forming apparatus is provided with a sheet feeding device that feeds a sheet by a feeding roller.

  By the way, as a conventional sheet feeding apparatus, there is an apparatus in which, for example, a sheet is blown by blowing air onto a sheet bundle as a predetermined initial operation before starting sheet feeding. And before feeding a sheet | seat in this way, the operation | movement which spreads a sheet | seat with air is performed also when replenishment, removal, or replacement | exchange of a sheet | seat is performed. In addition, the rolling operation performed in an auxiliary manner when the sheet is replenished in this way is hereinafter referred to as an auxiliary rolling operation.

  Here, the amount of air blown during the auxiliary rolling operation is in a state of close contact, such as when the sheet is newly replenished, or when the sheet that was in the lower layer is positioned in the upper layer by removing the sheet An amount that can roll the sheet is required. However, if the sheet that is positioned in the upper layer has already received air during the past sheet feeding operation, the amount of air to be blown can be at least sufficiently supplemented.

  In the conventional image forming apparatus, for example, when a sheet is newly replenished, as a predetermined initial operation, when the sheet is first fed, sheet type information such as the thickness and surface property of the fed sheet is displayed. Some of them detect and control image forming conditions based on the detection result. In the case of such an image forming apparatus, the initial output time from the start of feeding the first sheet to the completion of image formation for this sheet is increased by the time for detecting the sheet type.

  However, when the sheet is not changed, the initial output time can be reduced by omitting such a detection operation. Therefore, in the past, the detection operation is performed when there is a possibility that the sheet has been replaced, but if it is determined that the sheet has not been replaced, the detection operation is not performed, thereby eliminating unnecessary initial operations. I have to. In some cases, whether or not such a sheet has been replaced is determined based on power-on of the image forming apparatus main body, detection of cassette detachment by a sensor, detection of the presence or absence of a sheet, and the like (see Patent Document 1).

JP 2006-321215 A

  Incidentally, some conventional image forming apparatuses have a standby power mode for reducing power consumption during standby. In the case of such an image forming apparatus, the power may be turned off or the sensor may not be supplied with power because of a standby power state in the standby power mode.

  In this case, since it is not possible to determine whether or not a sheet has been replaced because the sensor does not detect the cassette removal or the like, when the power is turned on or the sleep mode is returned, the state of various detection mechanisms is affected. It is judged that all sheets have been replaced. However, in this case, since the initial operation is performed as if the sheet has been replaced even if the sheet has not been replaced, excess power is consumed, and the initial output time becomes longer, resulting in a decrease in productivity. Or

  Accordingly, the present invention has been made in view of such a current situation, and an object of the present invention is to provide an image forming apparatus capable of preventing excessive power consumption and productivity reduction.

  The present invention has a standby power mode in which the apparatus main body is in a standby state with low power consumption, and an image that performs a predetermined initial operation when the power is turned on or the standby power mode is canceled and sheet feeding is started. In the forming apparatus, a sheet storage unit provided in the apparatus main body and provided with a sheet stacking member for stacking the sheet so as to be movable up and down, a sheet feeding unit for feeding the sheet, and when feeding the sheet, the sheet is An elevating unit that raises the sheet stacking member until it can be fed by the sheet feeding unit, and the sheet reaches the position where the sheet feeding unit can feed the sheet by raising the sheet stacking member. A sheet detecting unit that detects the occurrence of the sheet, and when the power is turned on or the standby power mode is released, and the sheet detecting unit does not detect the sheet, And a control unit that controls to omit part or all of the initial operation when starting the sheet feeding when the sheet detection unit detects a sheet. It is characterized by.

  According to the present invention, when the power is turned on or when the standby power mode is canceled, if the sheet detection unit does not detect the sheet, the initial operation is performed, and if the sheet is detected, part or all of the initial operation is performed. By omitting, it is possible to prevent the consumption of excess power and a decrease in productivity.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to a first embodiment of the present invention. FIG. 3 illustrates a configuration of a sheet feeding device provided in the image forming apparatus. (A) is a figure which shows a state when the paper feed cassette of the said image forming apparatus is mounted | worn, (b) is a figure which shows a state when the paper feed cassette is extracted. (A) is a figure which shows the state when the sheet feeding cassette of the said sheet feeding apparatus is extracted, (b) is a figure which shows a state when mounting | wearing with a sheet feeding cassette. FIG. 6 is a diagram illustrating a configuration of a sheet feeding device provided in an image forming apparatus according to a second embodiment of the present invention. (A) is a figure which shows a state when the door member of the said image forming apparatus is closed, (b) is a figure which shows a state when the door member is opened.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to a first embodiment of the present invention. In FIG. 1, 10 is an image forming apparatus, and 11 is an image forming apparatus main body (hereinafter referred to as an apparatus main body). The apparatus main body 11 is provided with an image forming unit 2, a sheet feeding device 1 for feeding sheets stored in a sheet feeding cassette 101 which is a sheet storing unit for storing sheets, and the like. An image reading unit 3 is provided on the upper part of the apparatus main body 11.

  Here, the image reading unit 3 is supported so as to be openable and closable around a document table glass 303 and a hinge (not shown) with respect to the document table glass 303, and is opened and closed when a document is set on the document table glass 303. An automatic document feeder (hereinafter referred to as ADF) 302 is provided. The image reading unit 3 includes a light source that irradiates an image surface of a document, a CCD 305 that is a photoelectric conversion element (solid-state imaging device), and the like, and a scanner unit 301 that includes a carriage 304 that scans the document.

  The image forming unit 2 includes a photosensitive drum 203 that is rotated by a motor (not shown), a process cartridge 202 that includes a charger, a developing device, and a cleaner (not shown), a laser scanner 204 that exposes the photosensitive drum 203, and the like. Is provided. The image forming apparatus 10 according to the present embodiment has a sleep mode that is a standby power supply mode in which the apparatus main body 11 is in a standby state with low power consumption. Further, the image forming unit 2 includes a control unit 150 that performs predetermined initial operation control when starting an image forming operation of the image forming unit 2, a sheet feeding operation of the sheet feeding apparatus 1, and a sheet feeding described later.

  Next, an image forming operation of the image forming apparatus 10 having such a configuration will be described. First, a document (not shown) is stacked on the document table glass 303 with the image surface facing downward, and when the document is pressed against the document table glass 303 by the ADF 302, the carriage 304 moves while illuminating the document. Then, the image surface of the document is scanned. The original scanning light is imaged on the CCD 305 to read the original image.

  When reading an image of a document stacked on the document stacking tray 306 of the ADF 302, the document on the document stacking tray is separated and fed one by one by a document feeding roller 307, and the carriage 304 stopped in the scanner unit is stopped. The document reading position 308 is passed. During this passage, the carriage 304 reads a document image being conveyed.

  Thereafter, the read original image is input to an image processing unit (not shown), and after various image processing is performed in the image processing unit, it is output to the laser scanner 204 as an image information signal. The laser scanner 204 modulates the image information signal into an optical signal and irradiates the modulated optical signal onto the photosensitive drum. At this time, the photosensitive drum 203 is uniformly charged to a predetermined polarity and potential by a charger in advance, and an electrostatic latent image is formed by irradiation with an optical signal. Then, the electrostatic latent image formed on the photosensitive drum 203 in this way is developed by a developing device, whereby a toner image is formed on the photosensitive drum 203.

  On the other hand, one sheet S is separated from the sheet feeding apparatus 1 and sent out at a predetermined control timing in parallel with such an image forming operation. Thereafter, the fed sheet S is conveyed through a sheet path 201 to a transfer portion formed by the photosensitive drum 203 and the transfer roller 203a. When passing through the transfer portion, the toner image formed on the photosensitive drum 203 is transferred to the sheet.

  Next, the sheet onto which the toner image has been transferred is conveyed to the fixing device 205, and when passing through the fixing device 205, the toner image is fixed by applying heat and pressure. The sheet on which the toner image has been fixed is sent by the conveyance path switching member 206 to either the face-up conveyance path 207 or the switchback conveyance path 208 that reverses the sheet upside down. The sheet sent to the switchback conveyance path 208 is conveyed by the switchback conveyance roller 209 until the trailing edge of the sheet passes through the reverse switching member 210.

  Thereafter, the sheet is conveyed in the state of being inverted up and down by the reverse of the switchback conveying roller 209 with the rear end side so far as the leading end side. At this time, the reversed switching member 210 is switched, so that the reversed sheet is sent to the face-down conveyance path 211. Note that the face-up conveyance path 207 and the face-down conveyance path 211 merge before the discharge roller 212. As a result, both the sheet guided to the face-up conveyance path 207 and the sheet guided from the switchback conveyance path 208 to the face-down conveyance path 211 are discharged and stacked on the discharge stacking unit 4 by the discharge roller 212. The

  Next, the sheet feeding apparatus 1 will be described with reference to FIG. The sheet feeding apparatus 1 includes a pickup roller 105 that is a sheet feeding unit that feeds the uppermost sheet of a sheet bundle 109 stacked on a sheet feeding cassette 101 detachably provided in the apparatus main body 11. Further, a feed roller 106a and a retard roller 106b constituting a separation unit for separating and feeding the sheet fed from the pickup roller 105 are provided.

  Further, the apparatus main body 11 is not shown as a means for previously separating sheets in order to improve the sheet feeding performance of the pickup roller 105 and the separation feeding performance by the feed roller 106a and the retard roller 106b (to prevent double feeding). There are fans. In FIG. 2, 107 is a blower port, 108 is a nozzle that forms part of a blower path between a fan (not shown) and the blower port 107. When the fan is driven to start blowing air, After passing through 108, the sheet bundle 109 is blown from the blower port 107. Here, the air blowing port 107 is provided at a position where air can be blown to the sheet in the upper part of the sheet bundle 109 when the sheet bundle 109 is raised to a position where the sheet can be fed, which will be described later. Yes. Thus, when air is blown from the air blowing port 107, the sheet in the upper part of the sheet bundle is lifted and blown.

  In addition, as shown in FIG. 1, a sheet stacking plate, which is a sheet stacking member on which sheets can be stacked, is provided inside the sheet cassette 101 that is detachably mounted on the apparatus main body 11 (sheet feeding apparatus 1). Reference numeral 102 is provided so as to be movable up and down in a vertical direction by an elevator unit (not shown). Further, a side regulating plate 103 that abuts the side surface of the sheet bundle 109 and regulates the position in the width direction orthogonal to the sheet feeding direction, and a rear end regulating plate that regulates the upstream position of the sheet bundle 109 in the sheet feeding direction. 104 is provided.

  In FIG. 2, reference numeral 501 denotes a paper surface detection mechanism for detecting the paper surface position of the uppermost sheet 109a of the sheet bundle 109. The paper surface detection mechanism 501 includes a paper surface detection flag 502 and a paper surface detection sensor 503. . Then, as shown in FIG. 3A, when the paper feed cassette 101 is mounted on the apparatus main body 11, the control unit 150 drives the lifting unit. As a result, the sheet stacking plate 102 rises from the position shown in FIG. 4A, and accordingly, the uppermost sheet 109a of the sheet bundle 109 pushes up the paper surface detection flag 502 and turns on the paper surface detection sensor 503. When the paper surface detection sensor 503 is turned on in this way, the control unit 150 detects that the uppermost sheet 109a has been raised to a predetermined position where the pickup roller 105 can feed the sheet. When the paper surface detection mechanism 501 detects the paper surface in this way, the control unit 150 stops the lifting unit to stop the sheet stacking plate 102 from rising, and holds the upper surface of the uppermost sheet 109a of the sheet bundle 109 in a predetermined position. To do. As a result, the sheet can be fed.

  When the sheet cassette 101 is pulled out from the apparatus main body 11 as shown in FIG. 3B, the sheet stacking plate 102 is moved from the position shown in FIG. 4B to the position shown in FIG. Lowers due to the load on the seat. When the sheet stacking plate 102 is lowered in this way, the sheet bundle 109 is also lowered, and accordingly, the paper surface detection flag 502 is rotated downward, and the paper surface detection sensor 503 is turned off.

  In the present embodiment, as described above, in order to improve the performance of separation and feeding (prevention of double feeding), air from the fan is passed through the nozzle 108 in advance, and then is sent from the air outlet 107 to a predetermined position. The sheet bundle 109 that has been raised to the position is blown out.

  By the way, when a sheet bundle is replenished with respect to the sheet bundle 109, a sheet that has not received the air blow from the air blowing port 107 exists in the upper part of the sheet bundle 109. For this reason, after the sheet bundle is replenished and the like, before the sheet feeding is started, the air is blown for the blowing time when the normal sheet feeding operation is performed. On the other hand, a sheet that has been blown once after receiving air blowing can be spread in a short air blowing time even after a lapse of time.

  Therefore, after the sheet bundle is replenished, the blowing time before starting the feeding of the first sheet may be the first blowing time T1 when the normal sheet feeding operation is performed. Moreover, what is necessary is just to let the ventilation time when sheet bundle replenishment etc. are not performed be the 2nd ventilation time T2 shorter than 1st ventilation time T1. The shortened second blowing time T2 may be zero.

  Therefore, in the present embodiment, the control unit 150 determines whether the sheet bundle replenishment or the like has been performed, and if it is determined that the sheet bundle replenishment has been performed, the control unit 150 sets the first air blowing time T1 as the sheet bundle. When replenishment or the like is not performed, the second blowing time T2 is set. Then, the control unit 150 determines whether or not such sheet bundle replenishment has been performed by, for example, a signal of the paper surface detection sensor 503 when the power of the apparatus main body 11 is turned on or when the apparatus main body 11 returns from the sleep state. To do.

  Specifically, the control unit 150 detects that the sheet that has been lifted by the rising of the sheet stacking plate 102 has reached a position where the sheet can be fed when the power of the apparatus main body 11 is turned on. The paper surface detection sensor 503 which is a part is confirmed. When the paper surface detection sensor 503 is on, that is, when it is detected that the uppermost sheet has been raised to a predetermined position, it can be seen that the sheet stacking plate 102 has not been lowered. As a result, during the period when the power is off or the apparatus main body 11 is in the sleep state, it can be seen that the sheet feeding cassette 101 has not been pulled out, and it can be determined that sheets have not been replaced.

  On the other hand, when the paper surface detection sensor 503 is off, that is, when the uppermost sheet is lowered, it can be understood that the paper feed cassette 101 has been pulled out during the period when the power is off or in the sleep state. As a result, it can be determined that the sheet bundle may have been replaced. When it is determined that the sheet bundle is not exchanged based on the detection result of the paper surface detection mechanism 501 (paper surface detection sensor 503), the blowing time is set as the second blowing time T2, and the sheet bundle is exchanged. If there is a possibility, the first blowing time T1 is set.

  As described above, in the present embodiment, the presence / absence of sheet replacement is determined based on the detection result of the paper surface detection mechanism 501 (paper surface detection sensor 503), and the blowing time is set to the first or second based on the determination result. The air blow time is set. In other words, when the sheet detection mechanism 501 does not detect a sheet when the power is turned on or when the standby power mode is canceled, an initial operation for a normal time is performed, and when a sheet is detected, a part of the initial operation or Everything is omitted.

  Accordingly, it is possible to prevent the air from being blown unnecessarily for a long time even when the sheet bundle is not replenished, and the initial output time of the sheet can be shortened. As a result, it is possible to prevent excessive power consumption and productivity reduction. In addition, a simple sequence can be applied.

  In the above description, the example in which the initial blowing time is changed according to the detection result of the paper surface detection mechanism 501 has been described. However, other blowing parameters such as the blowing air amount, the wind speed, and the blowing gas temperature are changed. There may be. Alternatively, when the opening amount or opening position of the air blowing port 107 can be variably controlled, they may be changed.

  Next, a second embodiment of the present invention will be described. FIG. 5 is a diagram illustrating the configuration of the sheet feeding device provided in the image forming apparatus according to the present embodiment. In FIG. 5, the same reference numerals as those in FIG. 2 described above indicate the same or corresponding parts.

  In FIG. 5, a paper type 601 is provided on the downstream side of the feed roller 106a and the retard roller 106b, and acquires various sheet type information such as thickness and surface property of the sheets separated and fed by the feed roller 106a and the retard roller 106b. It is a detection unit. Here, paper type detection, which is an information acquisition operation by the paper type detection unit 601, is performed when the sheet is first fed. When such paper type detection is performed, conveyance of the sheet is stopped. There is a need. For this reason, the output time from the start of feeding a sheet for paper type detection to the completion of image formation is longer than that for a sheet for which paper type detection is not performed.

  In the past, when the image forming apparatus transitioned to a mode in which the power was not supplied to the sensor and the sensor status could not be grasped, such as when the power was turned off or in the sleep state, the sheet was replaced after the power was turned on or returned from sleep. Such paper type detection was performed as possible.

  However, even if the image forming apparatus shifts to the power-off or sleep state, if the sheet has not been replaced, it is not necessary to detect the paper type. Therefore, in the present embodiment, as in the first embodiment described above, whether or not to replace the sheet is determined based on the detection result of the paper surface detection mechanism 501, and if the sheet is not replaced, the paper type Detection is omitted. As a result, the output time is not unnecessarily prolonged, and the user's stress can be reduced. In addition, it is possible to save power and reduce sensor consumption of the paper type detection unit.

  Next, a third embodiment of the present invention will be described. FIG. 6 is a diagram illustrating the configuration of the image forming apparatus according to the present embodiment. In FIG. 6, the same reference numerals as those in FIG. 3 described above indicate the same or corresponding parts.

  In FIG. 6, reference numeral 301 denotes an accommodating portion that is formed in the lower portion of the apparatus main body 11 and detachably accommodates the paper feed cassette 101, and 302 is an openable / closable door member that shields the accommodating portion 301 from the outside. When the user replaces the sheet, the door member 302 is opened, and the sheet in the sheet feeding cassette 101 stored in the storage unit 301 is replaced. Here, in the present embodiment, when the control unit 150 detects that the door member 302 is released by a sensor (not shown), the control unit 150 controls the lifting unit to lower the sheet stacking plate 102 by its own weight. Yes.

  Accordingly, when the door member 302 is opened as shown in FIG. 6B, the sheet stacking plate 102 is lowered by its own weight as shown in FIG. Also descends. When the sheet bundle 109 is lowered in this way, the paper surface detection sensor 503 is also turned off. Then, by lowering the sheet stacking plate 102 in this way, the sheets can be exchanged without pulling out the paper feed cassette 101.

  Therefore, when the paper surface detection sensor 503 is turned on when the image forming apparatus 10 is turned on or returned from the sleep state, it can be seen that the door member 302 is not opened, thereby replacing the sheet. It can be determined that no has been made. In addition, when the paper surface detection sensor 503 is off, it can be seen that the door member 302 may be opened and closed during power-off or sleep, and the sheet may have been replaced.

  As described above, in the present embodiment, the opening / closing of the door member 302 is determined based on the detection result of the paper surface detection mechanism 501, and the presence / absence of sheet replacement is determined based on this determination. This makes it possible to omit part or all of the initial operations such as unnecessary air blowing and paper type detection described above, even though the sheet bundle is not replenished. The output time can be shortened.

DESCRIPTION OF SYMBOLS 1 ... Sheet feeding apparatus, 2 ... Image forming part, 10 ... Image forming apparatus, 11 ... Image forming apparatus main body, 101 ... Paper feed cassette, 102 ... Sheet stacking plate, 105 ... Pick-up roller, 107 ... Air blower, 108 ... Nozzle 109 ... Sheet bundle 109a ... Top sheet 150 ... Control part 301 ... Storage part 302 ... Door member 501 ... Paper surface detection mechanism 503 ... Paper surface detection sensor 601 ... Paper type detection part

Claims (5)

In an image forming apparatus having a standby power mode in which the apparatus main body is in a standby state with low power consumption, and performing a predetermined initial operation when the power is turned on or the standby power mode is canceled and sheet feeding is started.
A sheet storage unit provided in the apparatus main body, in which a sheet stacking member for stacking sheets is freely movable up and down;
A sheet feeding unit for feeding sheets;
When feeding a sheet, a lifting unit that raises the sheet stacking member until the sheet reaches a position where the sheet can be fed by the sheet feeding unit;
A sheet detection unit that detects that the sheet has reached a position where the sheet can be fed by the sheet feeding unit due to the rise of the sheet stacking member;
If the sheet detection unit does not detect a sheet when the power is turned on or the standby power mode is canceled, the initial operation is performed when the sheet feeding starts, and the sheet detection unit detects the sheet. In this case, an image forming apparatus comprising: a control unit that performs control so that part or all of the initial operation is omitted when sheet feeding is started. The predetermined initial operation is an operation of blowing air to the sheets stacked on the sheet stacking member,
2. The control unit according to claim 1, wherein when the sheet detection unit detects a sheet, the time for blowing air on the sheet is shortened or zeroed when the sheet feeding is started. Image forming apparatus. The predetermined initial operation is an operation of acquiring information on sheets stacked on the sheet stacking member,
The image forming apparatus according to claim 1, wherein when the sheet detection unit detects a sheet, the control unit does not perform an information acquisition operation when starting sheet feeding.   The said raising / lowering part is comprised so that the said sheet | seat stacking member may be fall | descended when the said sheet storage part is removed from the said apparatus main body. Image forming apparatus. A storage unit provided in the apparatus main body, for storing the sheet storage unit;
A door member for opening and closing the housing portion;
4. The image forming apparatus according to claim 1, wherein the control unit controls the elevating unit to lower the sheet stacking member when the door member is opened. 5.

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