Sheet carrier, image reader and image forming apparatus

Abstract

To provide a sheet carrier adapted to facilitate setting work of sheets different in size.SOLUTION: A sheet carrier comprises a loading unit on which a sheet is loaded, feed means that is arranged above the loading unit and feeds the sheet rested on the loading unit, elevation means that raises and lowers the loading unit between a first position to feed the sheet by the feed means and a second position below the first position and not to feed the sheet by the feed means, and control means that controls ascending / descending of the loading unit by the elevation means. The control means is allowed to select a mode allowing for feeding a plurality of sheets different in size rested on the loading unit by the feed means and if a mode is selected in a state the loading unit exists in the first position, the control means makes the loading unit move to the second position by the elevation means (S104) to wait for an instruction for a start of feeding.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a sheet conveying device that conveys a sheet, an image reading device that reads image information from a sheet, and an image forming apparatus that forms an image on a recording material. [Background technology]

[0002] 2. Description of the Related Art Image reading devices that read image information from original sheets include those equipped with an auto document feeder (ADF) that automatically feeds sheets set in a tray one by one.

[0003] Patent Document 1 describes an ADF that, when a sensor detects that a document has been placed on the lift plate, raises the lift plate to bring the document into contact with a feed roller and prepares for an instruction to start feeding the document. Patent Document 2 describes an ADF that has a function for automatically determining the document size for each document even when multiple documents of different sizes are placed on the document tray at the same time by detecting the width and length of the document transported from the document tray with a sensor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-263452 A [Patent Document 2] JP 2001-350225 A Summary of the Invention [Problem to be solved by the invention]

[0005] In an ADF that allows mixed document loading as in Patent Document 2, what was previously assumed was a mixture of relatively similar sizes of standard documents (sheet sizes defined in standards such as ISO216 and JIS P 0138), such as "A4 and B5." However, in recent years, there has been a demand for documents of non-standard sizes to be mixed with standard sizes in addition to standard sizes, and image information can be automatically read. Non-standard sizes refer to sheet sizes that do not fall under standard sizes, and examples of documents of non-standard sizes are receipts and checks.

[0006] However, when it is assumed that documents with widely different sizes are mixed, if the small documents are not placed in an appropriate position relative to the feed roller, feeding problems may occur. For example, when documents with a relatively small difference in width are mixed as shown in FIG. 1(a), the documents can often be conveyed normally by the feed roller 1 even if they are set to one side against the side regulation plate 31a on one side. However, when documents with a large difference in width are mixed and placed to one side as shown in FIG. 1(b), the small documents (gray parts) may not come into proper contact with the feed roller 1, resulting in feeding problems, so it is required to place the documents in an appropriate position as shown in FIG. 1(c). In this case, the small documents are set without contacting the side regulation plate 31a, and as shown in FIG. 1(d), they may become inclined and need to be repositioned. It is also possible to mix documents by placing a document of a certain size first and then stacking a document of a different size on top of it.

[0007] For these reasons, in a mode in which documents of widely differing sizes are mixed, if the document tray (lift plate) is raised when the documents are placed as in Patent Document 1, the documents are pressed against the feed roller 1 (Figure 2), which can make it difficult to set the documents.

[0008] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a sheet conveying device, an image reading device, and an image forming apparatus that facilitate the setting operation of sheets of different sizes. [Means for solving the problem]

[0009] One aspect of the present invention is a sheet feeding device that includes a loading section on which sheets are loaded, a detection unit that detects the sheets loaded on the loading section, a feeding unit that is disposed above the loading section and feeds the sheets loaded on the loading section, a lifting unit that raises and lowers the loading section between a first position where the sheets loaded on the loading section contact the feeding unit and a second position that is a position lower than the first position, and a control unit that controls the lifting and lowering of the loading section by the lifting unit, wherein the control unit is capable of executing a first mixed mode in which a plurality of sheets of different sizes, including non-standard sizes, are mixed and fed by the feeding unit, and a second mixed mode in which a plurality of sheets of different standard sizes are mixed and fed by the feeding unit. and when the detection means detects a sheet while the loading section is at the second position and the first mixed loading mode is selected, the detection means waits without executing an operation of moving the loading section to the first position using the lifting means until a feeding start instruction is received, and moves the loading section from the second position to the first position using the lifting means based on the receipt of the feeding start instruction, and when the loading section is at the second position and the second mixed loading mode is selected, when the detection means detects a sheet, the detection means moves the loading section from the second position to the first position using the lifting means based on the detection of the sheet by the detection means.

[0010] Another aspect of the present invention is a sheet feeding device that includes a loading section on which sheets are loaded, a detection unit that detects the sheets loaded on the loading section, a feeding unit that is disposed above the loading section and feeds the sheets loaded on the loading section, a lifting unit that raises and lowers the loading section between a first position where the sheets loaded on the loading section contact the feeding unit and a second position that is a position lower than the first position, and a control unit that controls the lifting and lowering of the loading section by the lifting unit, wherein the control unit has a first mixed mode in which a plurality of sheets of different sizes including non-standard sizes are mixed and fed by the feeding unit, and a second mixed mode in which a plurality of sheets of different standard sizes are mixed and fed by the feeding unit. and when the detection means detects a sheet when the loading unit is at the second position and the first mixed loading mode is selected, the lifting means moves the loading unit to a third position between the first position and the second position and waits, and when a feeding start instruction is received, the lifting means moves the loading unit from the third position to the first position, and when the loading unit is at the second position and the second mixed loading mode is selected, the lifting means moves the loading unit from the second position to the first position, based on the detection of the sheet by the detection means.

[0011] Yet another aspect of the present invention is a sheet conveying device comprising a loading section on which sheets are loaded, a detection means for detecting the sheets loaded on the loading section, a feeding means arranged above the loading section and feeding the sheets loaded on the loading section, a lifting means for raising and lowering the loading section between a first position at which the sheets loaded on the loading section contact the feeding means and a second position which is a position lower than the first position, and a control means for controlling the raising and lowering of the loading section by the lifting means, wherein the control means moves the loading section from the second position to a third position between the first position and the second position using the lifting means based on the detection means detecting a sheet, and moves the loading section from the third position to the first position using the lifting means based on receiving a feeding start instruction. Effect of the Invention

[0012] According to the present invention, the setting operation of sheets of different sizes can be facilitated. [Brief description of the drawings]

[0013] [Figure 1] 1A to 1D are diagrams for explaining the setting positions of a standard-form document and an irregular-form document. [Diagram 2] FIG. 13 is a diagram showing a state in which it is difficult to reposition the document. [Diagram 3] FIG. 1 is a perspective view of an image reading apparatus according to a first embodiment. [Figure 4] FIG. 2A is a cross-sectional view of an ADF according to the first embodiment, and FIG. [Diagram 5] FIG. 1 is a block diagram of an image reading apparatus according to a first embodiment. [Figure 6] 1 is a cross-sectional view showing a part of an image reading apparatus according to a first embodiment (when a document tray is in a lowered position). [Figure 7] 1 is a cross-sectional view showing a part of an image reading apparatus according to a first embodiment (when a document tray is in a raised position). [Figure 8] FIG. 4 is a diagram showing a selection screen for an operation mode of the image reading apparatus according to the first embodiment. [Figure 9] 9 is a diagram showing a screen displayed when mixed scanning of non-standard sizes is selected on the selection screen of FIG. 8 . [Figure 10] 4 is a flowchart showing a control method of the image reading apparatus according to the first embodiment. [Figure 11] 1 is a cross-sectional view showing a part of an image reading apparatus according to a first embodiment (when a document tray is in a standby position). [Figure 12] 10 is a flowchart showing a control method of an image reading apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. EXAMPLES

[0015] 3 is a perspective view showing an image reading device 150 in the first embodiment. The image reading device 150 in this embodiment is composed of a reader unit 100 that reads image information from a document, and an ADF 200 that transports the document toward a reading position where reading is performed by the reader unit 100. The ADF 200 is a sheet transport device in this embodiment. The ADF 200 is supported by an opening / closing hinge provided on the rear side of the upper surface of the reader unit 100 so as to be openable and closable with respect to the reader unit 100.

[0016] The image reading device 150 can perform two types of reading operations for reading image information from a document: a fixed reading operation and a flow reading operation. The fixed reading operation is an operation for reading image information from a stationary document placed on the document table glass 101 of the reader unit 100, and the flow reading operation is an operation for reading image information while feeding the document one sheet at a time by the ADF 200.

[0017] <Leader> The reader unit 100 will be described with reference to Fig. 4(a). Fig. 4(a) is a cross-sectional view showing a schematic configuration of an image reading device 150 in this embodiment.

[0018] The reader unit 100 has a document glass table 101, a front surface scanning glass 102, a front surface reading unit 105, an optical motor 306 (not shown in FIG. 5), and a reading movement guide 109. The front surface reading unit 105 is a line sensor unit having front surface LEDs 103a and 103b as light sources, a front surface reading sensor 108 as an imaging element such as a charge coupled device, and a plurality of mirrors 104a, 104b, and 104c. The front surface reading unit 105 is supported by a carriage driven by the optical motor 306, and can move back and forth in the left and right directions in the figure.

[0019] In the case of fixed reading operation, the front surface reading unit 105 scans the original on the original platen glass 101 while moving below the original platen glass 101 by the drive of the optical motor 306, thereby reading the image information of the original line by line. In the case of flow reading operation, as described below, the front surface reading unit 105 scans the original being transported by the ADF 200 via the front surface flow reading glass 102, and reads the image information of one side of the original line by line.

[0020] <adf> The ADF 200 will be described with reference to Fig. 4(a). The ADF 200 has a document tray 30, a feed roller 1, a separation roller 2, a separation pad 21, a document presence sensor 10, and a length sensor 9 on the tray.

[0021] The document tray 30 is a loading section in this embodiment on which sheets used as documents are placed. As documents, various sheets of different sizes and materials can be used, including paper such as plain paper and thick paper, sheet materials with surface treatments such as plastic film, cloth, and coated paper, and sheet materials with special shapes such as envelopes and index paper.

[0022] At least a portion of the document tray 30 is configured to be movable up and down by a tray lift motor 312 (FIG. 5) described later. For example, the downstream portion of the document tray 30 in the document feed direction (leftward in the figure) is configured to be movable up and down relative to the frame of the ADF 200, and the lower surface is supported by a lift plate connected to the tray lift motor 312 via a gear. When the skim-reading operation is performed, the document tray 30 is raised so that the document stack S on the document tray 30 comes into contact with the feed roller 1 with an appropriate contact pressure.

[0023] The document tray 30 is provided with a pair of side regulating plates 31a, 31b (see FIG. 1(a)) as regulating members for regulating the document position in the width direction perpendicular to the document feeding direction. The side regulating plates 31a, 31b are provided so as to be movable in conjunction with each other in the width direction around the center position of the feed roller 1 in the width direction, and can abut against the side edges of the document placed on the document tray 30 to regulate the document position.

[0024] The feed roller 1 is a feeding means in this embodiment that feeds sheets from the stacking portion. The feed roller 1 is disposed above the document tray 30, and is provided at the center position of the document tray 30 in the width direction (see FIG. 1(a)). The feed roller 1 abuts against the document stack S on the document tray 30 during the execution of the skimming operation, and sends the topmost document toward the separation roller 2. The separation roller 2 and the separation pad 21 are an example of a document separation mechanism, and the separation pad 21 applies frictional force to the document entering the separation nip between the separation roller 2 and the separation pad 21, and the documents are separated one by one and transported. The feed roller 1 is an example of a feeding means, and a device that sends out documents from the document tray 30 by a belt member, for example, may be used.

[0025] The document presence sensor 10 is provided near the downstream end of the document tray 30 in the sheet feeding direction (particularly downstream from the document abutment position of the feed roller 1), and is configured to change a detection signal depending on the presence or absence of a document on the document tray 30. That is, the document presence sensor 10 functions as a detection means in this embodiment for detecting the presence or absence of a document on the stacking section. The tray length sensor 9 is provided at a predetermined detection position on the document tray 30 in the sheet feeding direction, and is configured to change a detection signal depending on the presence or absence of a document at the detection position. The tray length sensor 9 is used to determine the length of the document on the document tray 30 in the transport direction. The document presence sensor 10 and the tray length sensor 9 may be, for example, a light-shielding photoelectric sensor that is shielded by a flag that is pressed against the document and swings, or a reflection-type photoelectric sensor that irradiates detection light toward the top of the document tray 30 and detects reflected light from the document.

[0026] The ADF 200 further includes a pull-out roller 3, a transport roller 4, an upstream reading roller 5, a front glass facing member 6, an intermediate transport roller 7, a back surface reading unit 202, a back surface running reading glass 201, a back surface glass facing member 8, a discharge roller 16, a discharge tray 17, etc.

[0027] The original document sent from separation roller 2 is transported via pull-out roller 3, transport roller 4, and upstream reading roller 5 toward the reading position of front surface reading unit 105. At the reading position of front surface reading unit 105, the original document is transported passing between front surface flow reading glass 102 and front surface glass facing member 6. At this time, image information on the first side (front surface) of the original document is read line by line by front surface reading unit 105. Furthermore, reading accuracy is ensured by pressing the original document against front surface flow reading glass 102 by roller members 51, 52 provided upstream and downstream of the reading position.

[0028] The document that has passed the reading position of the front side reading unit 105 is transported toward the reading position of the back side reading unit 202 via the intermediate transport roller 7. At the reading position of the back side reading unit 202, the document is transported passing between the back side scanning glass 201 and the back side glass facing member 8. At this time, image information on the second side (back side) of the document is read line by line by the back side reading unit 202. Note that the back side scanning glass 201 is movable, and when image information is to be read from the back side, the document is moved in advance to the position shown in FIG. 4(a) before it reaches the reading position of the back side reading unit 202. Also, roller members 53 and 54 provided on the upstream and downstream sides of the reading position press the document against the back side scanning glass 201, thereby ensuring reading accuracy.

[0029] The back side reading unit 202 is a line sensor unit having LEDs 203a and 203b as light sources, a back side reading sensor 208 as an imaging element such as a charge coupled device, and multiple mirrors 204a, 204b, and 204c. Note that the front side reading unit 105 and the back side reading unit 202 are both examples of a reading means for reading image information, and for example, a contact image sensor (CIS) equipped with a life-size optical system may be used.

[0030] The document that has passed the reading position of the back-side reading unit 202 is discharged to the outside of the ADF 200 by the discharge rollers 16 and is stacked on the discharge tray 17. When multiple documents are stacked on the document tray 30, the image reading device 150 reads image information from each document by repeatedly executing the above operations of feeding, reading, and discharging the documents.

[0031] Incidentally, a separation sensor 11, a pull-out sensor 12, a transport sensor 13, a lead sensor 14, and a discharge sensor 15 are provided as transport system sensors for monitoring the transport of the original at various points in the transport path inside the ADF from the feed roller 1 to the discharge roller 16. The controller of the image reading device 150 judges whether the transport of the original is proceeding normally based on the time when these sensors detect the passage of the leading or trailing end of the original.

[0032] Further, although the case where image information is read from both sides of the document has been described here, when image information is read from only one side of the document, the document is simply transported past the reading position of the back-side reading unit 202 without being read by the back-side reading unit 202.

[0033] <Image forming device> As one mode of use of the image reading device 150, Fig. 4(b) shows an image forming device 180 in which the image reading device 150 is mounted on the top of the image forming device main body 160. The image forming device main body 160 houses an electrophotographic image forming unit PU as an image forming means, and the reader unit 100 of the image reading device 150 is fixed to the frame of the image forming device main body 160.

[0034] The image forming device 180 can perform an image forming operation (copying operation) for forming an image on a recording material P based on image information read by the image reading device 150. In the image forming unit PU, the charger 162 uniformly charges the surface of the photoconductor 161, and the exposure device 163 irradiates the photoconductor 161 with laser light modulated based on image information to write an electrostatic latent image. The developing device 164 supplies a developer containing charged toner particles to the photoconductor 161, and develops the electrostatic latent image to visualize it as a toner image. The transfer device 165 transfers the toner image carried by the photoconductor 161 to the recording material P. The cleaning device 166 removes deposits such as transfer residual toner remaining on the photoconductor 161 without being transferred to the recording material P. The fixing device 167 applies heat and pressure to the toner image on the recording material P to melt the toner, thereby fixing the toner image to the recording material P.

[0035] The image reading device 150 can also be used as a device independent of the image forming device main body. In that case, image information read by the image reading device 150 is transferred to an external computer via a network, for example. Also, the one shown in FIG. 4(b) is an example of an image forming device, and an inkjet printing unit, for example, may be used as the image forming means.

[0036] <Control configuration of image reading device> Fig. 5 is a block diagram showing the control configuration of the image reading device 150 according to this embodiment. The image reading device 150 includes a reader controller 300. The reader controller 300 includes a reader CPU 301, which is a central processing unit, a ROM-A 302, which is a read-only memory, and a RAM-A 303, which is a random access memory. A control program is stored in the ROM-A 302, and input data and working data are stored in the RAM-A 303. The reader CPU 301 reads and executes the control program stored in the ROM-A 302, thereby functioning as a control means for controlling the operation of the image reading device 150 according to a flow described later with reference to Fig. 10.

[0037] The reader CPU 301 is connected to the tray lift motor 312, the feed roller lift motor 311, the feed motor 310, the transport motor 307, and the optical motor 306, which are actuators of the image reading device 150, and controls the driving state of each motor. The tray lift motor 312 is a motor that lifts and lowers the document tray 30, and is the lifting means in this embodiment. The feed roller lift motor 311 is a motor that lifts and lowers the feed roller 1 (FIG. 4). The feed motor 310 is a motor that drives the feed roller 1 and the separation roller 2. The transport motor 307 is a motor that drives the pull-out roller 3, the transport roller 4, the reading upstream roller 5, the intermediate transport roller 7, and the discharge roller 16.

[0038] In this embodiment, both the feed motor 310 and the transport motor 307 are pulse motors, and the reader CPU 301 manages the rotation amount of each motor by controlling the number of drive pulses of these motors. Therefore, the number of drive pulses can be regarded as the transport distance of the document being transported. In other words, the reader CPU 301 can measure the transport distance of the document by counting the number of drive pulses of the feed motor 310 and the transport motor 307.

[0039] The reader CPU 301 is connected to the document presence / absence sensor 10, the length sensor on the tray 9, and the document width sensor 309, which are provided on the document tray 30. The document width sensor 309 can be, for example, a volume sensor provided on a pinion gear of a rack and pinion that links the side regulating plates 31a and 31b. The reader CPU 301 can predict the size of the document placed on the document tray 30 based on the detection results of the length sensor on the tray 9 and the document width sensor 309. In addition, a more accurate value for the length of the document can be obtained by using a transport system sensor while the document is being transported.

[0040] The reader CPU 301 also has an upward position detection sensor 314 and a downward position detection sensor 315 as detection means for detecting the current position of the document tray 30 for use in lift control. The upward position detection sensor 314 is a sensor for detecting that the top surface of the document stack placed on the document tray 30 is at a predetermined height at which the document stack can be fed by the feed roller 1. Hereinafter, the position of the document tray 30 when the top surface of the document stack is at the predetermined height is referred to as the upward position. The downward position detection sensor 315 is a sensor for detecting that the document tray 30 is at a position (hereinafter referred to as the downward position) where the document tray 30 waits when the ADF 200 does not transport documents. The upward position is the first position in this embodiment, and the downward position is the second position in this embodiment.

[0041] When the feed motor 310 drives the feed roller 1 and the separation roller 2 while the document tray 30 is in the raised position, documents are fed one by one from the document tray 30. On the other hand, when the document tray 30 is in the lowered position, the documents on the document tray 30 do not come into contact with the feed roller 1, and feeding of the documents does not start.

[0042] The reader CPU 301 is also connected to transport system sensors (comprising the separation sensor 11, the pull-out sensor 12, the transport sensor 13, the lead sensor 14, and the discharge sensor 15 in FIG. 4) provided at various points on the transport path. The reader CPU 301 judges whether the transport operation of the document being transported is proceeding normally based on the detection signals of the transport system sensors.

[0043] Furthermore, to realize an image reading function, the reader CPU 301 is connected to front and back LEDs (103a, 103b, 203a, 203b), front and back reading sensors (108, 208), an image processing unit 304, and an image memory 305. The reader CPU 301 causes the image processing unit 304 to perform various image processes on the image data read by the front and back reading line sensors (108, 208), and then stores the image in the image memory 305. The image processing refers to, for example, shading correction that corrects the brightness, etc. of the current image data based on the read data of the white reference plates 110, 210 (FIG. 4) previously read by the front reading unit 105 and the back reading unit 202.

[0044] The reader CPU 301 transmits the image data stored in the image memory 305 to the system controller 400 via the image data bus 318 in accordance with an image output request received from the system controller 400 via the command data bus 317. Furthermore, the reader CPU 301 notifies the system controller 400 via the image data bus 318 of a vertical synchronizing signal that is the reference for the leading edge of the original image data and a horizontal synchronizing signal that is the reference for the leading edge of one line of pixels in accordance with the timing of reading the original.

[0045] The system controller 400 includes a system CPU 411, a system ROM 412, and a system RAM 413, and exchanges data related to image reading control with the reader CPU 301 via a command data bus 317. Image data processed by the image processing unit 304 of the image reading device is transferred to an image processing unit 414 in the system controller 400 via an image data bus 318, where it is subjected to predetermined image processing such as color judgment, and then stored in an image memory 415. The system controller 400 also includes an operation unit 416, and the system CPU 411 controls the interface with the user via the operation unit 416. The operation unit 416 includes a display device such as a liquid crystal panel that displays information by image, and an input device that accepts input operations from the user, such as physical buttons or a touch panel function unit of the liquid crystal panel.

[0046] The system controller 400 functions as a control unit that controls the entire device including the ADF 200 and the reader unit 100. For example, in the case of the image forming device 180 shown in FIG. 4(b), the system controller 400 may be a control board mounted on the image forming device main body 160. In this case, the system controller 400 can cause the image forming unit to perform an image forming operation based on image information received from the reader controller 300. Furthermore, the reader controller 300 may be installed outside the housing of the ADF 200 or the reader unit 100 (for example, inside the image forming device main body) as long as it is appropriately connected to the above-mentioned motors and sensors.

[0047] <About mixed document scanning> Next, a method for identifying the size of documents when reading image information from documents of different sizes (hereinafter, referred to as mixed reading) will be described. When reading mixed documents, multiple types of documents with different widths (document length in the width direction) or lengths (document length in the feeding direction) are allowed to be placed together on the document tray 30.

[0048] When mixed-load scanning is not performed (for example, when only one type of standard size is handled), the document size can be determined by detecting the width of the document using document width sensor 309 (FIG. 5) present on document tray 30 and detecting the length of the document using separation sensor 11 after document transport begins. That is, the document length is measured based on the elapsed time from when separation sensor 11 detects the leading edge of the current document until separation sensor 11 detects the trailing edge of the current document, and the document transport speed by separation roller 2 and pull-out roller 3. Reader CPU 301 stores image data read by front surface reading unit 105 and back surface reading unit 202 in image memory 305 for the required width (main scanning direction range) and length (sub-scanning direction range) based on the determined document size.

[0049] However, in the case of mixed-load scanning, side regulating plates 31a and 31b on document tray 30 are positioned according to the widest document, so the detection result of document width sensor 309 does not reflect the widths of the other documents. Therefore, in the case of mixed-load scanning, a separate means is used to detect the size of each document and specify the range for acquiring image data.

[0050] In the case of mixed reading, the length of the document is measured based on the detection result of the separation sensor 11, as in the case of other than mixed reading described above. The width of the document is measured by performing edge detection on the primary image data read by the front side reading unit 105. That is, the image processing unit 304 of the reader controller 300 analyzes the primary image data received from the front side reading sensor 108, identifies both side edges (edges of the document in the width direction), and calculates the distance between the side edges as the document width. The reader CPU 301 stores the image data read by the front side reading unit 105 and the back side reading unit 202 in the image memory 305 for the required width (main scanning direction range) and length (sub-scanning direction range) based on the document size identified as above.

[0051] <Placement of originals in the original tray> Next, the setting position of the document on the document tray 30 will be described separately for the case of mixed reading and the case of other than mixed reading.

[0052] When the ADF 200 is not transporting documents, the document tray 30 waits in the lowered position (FIG. 6). When a document stack S is placed on the document tray 30, the detection signal of the document presence / absence sensor 10 changes, and the reader CPU 301 determines that a document is present and starts lifting the document tray 30 using the tray lift motor 312. Then, when the lift position detection sensor 314 (FIG. 5) issues a detection signal indicating that the top surface of the document stack S has reached a predetermined height, the lifting of the document tray 30 ends (FIG. 7).

[0053] When the document tray 30 is in the raised position, the document stack S is in contact with the feed roller 1, so that document feeding can be started immediately by driving the feed roller 1 with the feed motor 310. In other words, by moving the document tray 30 to the raised position when the document presence sensor 10 detects the document, the waiting time from the user's instruction to execute reading to the acquisition of image data can be shortened.

[0054] Incidentally, in cases other than mixed-load scanning, when placing a stack of documents S on the document tray 30, the user manually adjusts the position of the side regulating plates 31a and 31b (FIG. 1(a)) to match the width of the documents. The reader CPU 301 uses the value acquired based on the detection result of the document width sensor 309 as the width of the documents placed on the document tray 30 to execute the skimming operation.

[0055] On the other hand, in the case of mixed-load reading, a plurality of documents of different sizes may be placed on the document tray 30, and in particular, documents of very small widths such as non-standard sizes may be mixed with documents of standard sizes. Therefore, as described with reference to FIG. 1(b), in the case of mixed-load reading, documents of each size are required to be set in the center position of the document tray 30 as shown in FIG. 1(c), rather than being set to one side against one of the side regulating plates 31a. The image reading device 150 notifies the user of the appropriate document setting position, for example, via the operation unit 416 (FIG. 5).

[0056] In this way, when setting documents at a position away from the side regulating plates 31a and 31b, small documents tend to tilt and need to be repositioned as shown in Fig. 1(d). However, as described above, if the document tray 30 is moved to the raised position when the document presence sensor 10 detects the document, the document stack S is pressed down by the feed roller 1 (Fig. 2), making it difficult to reposition the documents. Therefore, in this embodiment, we propose to facilitate the setting of mixed documents by appropriately controlling the position of the document tray 30 in a mode for reading mixed documents including non-standard sizes, as will be described later.

[0057] <About mixed-size document scanning> The function of scanning mixed documents including non-standard sizes in this embodiment will be described with reference to FIGS.

[0058] 8 shows a selection screen displayed on operation unit 416 when no reading operation is being performed after power-on of image reading device 150. Buttons b1 to b6 in the figure are sections that allow the selection of functions to be executed by image reading device 150 by touching the screen.

[0059] When the user wishes to read image information of a mixture of documents including documents of irregular sizes, the user selects the button b4 for "mixed reading of irregular sizes". Then, the screen display of the operation unit 416 transitions to the execution screen shown in Fig. 9. On this execution screen, a button c1 for instructing the start of the reading operation, buttons c2 to c6 for detailed setting of the reading operation, and a message c7 for informing the user of the setting position of the documents are displayed. In this embodiment, when the mixed reading mode of irregular sizes is selected, a message c7 is displayed instructing the user to set the documents in the center position of the document tray 30.

[0060] In FIG. 8, the operation of selecting the button b4 of "mixed reading of irregular sizes" corresponds to the first mode in this embodiment. In addition, the operation of selecting the buttons b1, b2, b3, and b5 other than "mixed reading of irregular sizes" in FIG. 8 to perform the reading operation corresponds to the second mode in this embodiment. In the modes other than the mixed reading of irregular sizes, it is possible to read a stack of documents of the same size of regular sizes and to perform mixed reading of regular sizes. In addition, when the mixed reading mode of irregular sizes is selected, the document is set at the center position of the document tray 30 as shown in FIG. 1(c). On the other hand, when a mode other than the mixed reading of irregular sizes is selected and mixed reading of regular sizes of documents is performed, the document is set to one side against the side regulating plate 31a on one side as shown in FIG. 1(a).

[0061] In this embodiment, the term "standard size" refers to a size that is often used as a general document and is registered in advance in a storage unit such as the ROM-A302, and the term "non-standard size" refers to a size other than the registered size. Therefore, non-standard sizes include sizes whose width is smaller than the minimum value of the standard sizes.

[0062] 10 is a flowchart showing a method for controlling the image reading device 150 according to this embodiment. Each step of this flow is realized by the reader CPU 301 reading and executing a control program stored in the ROM-A 302.

[0063] After the image reading device 150 is powered on, the process of this flowchart starts, and the selection screen of FIG. 8 is displayed on the operation unit 416. The reader CPU 301 monitors whether the button b4 for "mixed scanning of irregular sizes" has been selected (S101). When the user selects "mixed scanning of irregular sizes" via the operation unit 416, a notification that mixed scanning of irregular sizes will be performed is sent from the system controller 400 to the reader controller 300 via the command data bus 317. Upon receiving the notification, the reader CPU 301 changes the irregular size document reading flag to TRUE (S102).

[0064] Next, the reader CPU 301 checks whether the document presence / absence sensor 10 has been turned ON and the document tray 30 has moved to the raised position (FIG. 7) by the current time (S103). If the document tray 30 has moved to the raised position (S103 YES), the reader CPU 301 moves the document tray 30 to the lowered position (FIG. 6) (S104).

[0065] That is, when a mode for reading mixed originals is selected with the original tray 30 in the raised position, in this embodiment, control is performed to move the original tray 30 from the raised position to the lowered position. This prevents the feed roller 1 from contacting the originals, making it easier to reposition or add originals of non-standard sizes on the original tray 30, and making it easier to set mixed originals including non-standard sizes in appropriate positions. After moving the original tray 30 to the lowered position, the reader CPU 301 waits until the user issues an instruction to start reading (start feeding originals, button c1 in FIG. 9) via the operation unit 416 (S109).

[0066] On the other hand, when the user selects "mixed scanning of non-standard sizes," if the document tray 30 is in the lowered position (FIG. 6) (S103 NO), the reader CPU 301 waits until a document is placed while maintaining the document tray 30 in the lowered position (S105). In this case, if the document presence sensor 10 is turned ON due to a new document being placed on the document tray 30 (S105 YES), it is confirmed whether or not the mixed scanning of non-standard sizes mode has been selected (S106). If the mixed scanning of non-standard sizes mode has been selected (S106 YES), the document tray 30 is not raised and is kept waiting in the lowered position (S107).

[0067] As a result, even if documents are placed on the document tray 30 after selecting mixed scanning of non-standard sizes, the document tray 30 remains in the lowered position, so that it is easy to reposition or add mixed documents including non-standard sizes.

[0068] If the document is placed on the document tray 30 and non-standard size document reading is not selected (S101 NO, S105 YES, S106 NO), the reader CPU 301 moves the document tray 30 to the raised position (S108) and waits until the user selects to start reading via the operation unit 416 (S109).

[0069] When the user issues a command to start reading (S109 YES), the reader CPU 301 checks whether the document tray 30 is in the raised position (S110). If the document tray 30 is in the raised position when the command to start reading is received (S110 YES), the feed roller 1 and other elements are driven while the document tray 30 is maintained in the raised position. As a result, the documents placed on the document tray 30 are fed one by one, and image information is read (S112).

[0070] On the other hand, if the document tray 30 is not in the raised position when the instruction to start reading is received (NO in S110, i.e., in the lowered position), the document tray 30 is moved to the raised position (S111) and then the feed roller 1 and the like are started to be driven. Then, image information is read from the document transported along the transport path in the ADF 200 (S112).

[0071] When all the documents placed on the document tray 30 have been transported and reading of the image information has been completed (S113 YES), the reader CPU moves the document tray 30 to the lowered position (S114) and returns to S101 to continue the process.

[0072] By controlling in accordance with the above flowchart, when the mode for reading mixed documents of irregular sizes is selected, document tray 30 waits in the lowered position until a command to start reading is given, making it easier to set mixed documents including those of irregular sizes.

[0073] (Variation 1) In the above embodiment, the document tray 30 was lowered in synchronization with the transition from the selection screen (FIG. 8) for selecting the reading operation mode to the execution screen for mixed scanning of non-standard sizes (FIG. 9), but the screen transition does not necessarily have to be synchronized with the lowering of the document tray 30. For example, when the button b4 for mixed scanning of non-standard sizes is pressed on the selection screen, if the selection result is indicated by changing the color of the button b4 and the selection screen continues to be displayed, the document tray 30 may be lowered based on the pressing of the button b4.

[0074] (Variation 2) In the above embodiment, when the mixed non-standard size scanning mode is selected as the first mode, the standby position of the document tray 30 is set to the lowered position. However, even when standard sizes are mixed, if the widths of the documents differ greatly, the problem described using Figures 1(a-d) may occur. Therefore, the same control as in the above embodiment may be applied to a mode that allows only standard sizes to be mixed. EXAMPLES

[0075] As the second embodiment, a configuration example will be described in which the standby position of the document tray 30 is set to a position other than the lowered position when the non-standard size mixed scanning mode is selected. In the following, elements with the same reference numerals as in the first embodiment have substantially the same configurations and functions as those in the first embodiment, and the following will focus on the differences from the first embodiment.

[0076] FIG. 11 shows the standby position where the document tray 30 waits until reading starts when a mode for reading documents of a non-standard size is selected in this embodiment. The standby position of the document tray 30 in this embodiment is a specific position between the raised position and the lowered position. In other words, when the raised position is the first position and the lowered position is the second position, the standby position in this embodiment is a third position between the first position and the second position. The standby position is a position where the document stack S on the document tray 30 does not contact the feed roller 1 (i.e., a position where the raised position detection sensor 314 (FIG. 5) is OFF). In addition, the standby position is a position above the lowered position, which is the lower limit position of the movement range of the document tray 30 (a position where the lowered position detection sensor 315 (FIG. 5) is OFF).

[0077] By having the document tray 30 wait at such a standby position, the time required to move the document tray 30 from the standby position to the raised position when an instruction to start reading is given is shorter than the time required to move the document tray 30 from the lowered position to the raised position. In other words, compared to the first embodiment in which the document tray 30 waits at the lowered position when a mode for reading documents of non-standard sizes is selected, the waiting time from the instruction to start reading until the first document is fed can be shortened. Meanwhile, since the top surface of the document stack S is not in contact with the feed roller 1 even when the document tray 30 is at the standby position, the setting operation of mixed documents including non-standard sizes can be easily performed as in the first embodiment.

[0078] 12 is a flowchart showing a method for controlling the image reading device 150 according to this embodiment. Each step of this flow is realized by the reader CPU 301 reading and executing a control program stored in the ROM-A 302.

[0079] After the image reading device 150 is powered on, the process of this flowchart starts, and the selection screen of FIG. 8 is displayed on the operation unit 416. The reader CPU 301 monitors whether the button b4 for "mixed scanning of non-standard sizes" has been selected (S201). When the user selects "mixed scanning of non-standard sizes" via the operation unit 416, a notification that non-standard size mixed scanning will be performed is sent from the system controller 400 to the reader controller 300 via the command data bus 317. Upon receiving the notification, the reader CPU 301 changes the non-standard size document scanning flag to TRUE (S202).

[0080] Next, the reader CPU 301 checks whether the document presence / absence sensor 10 has been turned ON and the document tray 30 has moved to the raised position (FIG. 7) by the current time (S203). If the document tray 30 has moved to the raised position (S203 YES), the reader CPU 301 moves the document tray 30 to the standby position in FIG. 11 (S204). Specifically, the reader CPU 301 starts lowering the document tray 30 by the tray lift motor 312, and then continues driving the tray lift motor 312 for a predetermined number of pulses after the raised position detection sensor 314 (FIG. 5) turns OFF, and then stops the motor.

[0081] The lowering operation of S204 moves the document tray 30 to a standby position where the document stack S is a predetermined distance away from the feed roller 1. This prevents the feed roller 1 from coming into contact with the documents, making it easier to reposition or add documents of non-standard sizes on the document tray 30, and facilitating the task of setting mixed documents including non-standard sizes in appropriate positions. After moving the document tray 30 to the standby position, the reader CPU 301 waits until the user issues an instruction to start reading (button c1 in FIG. 9) via the operation unit 416 (S209).

[0082] On the other hand, when the user selects "mixed scanning of non-standard sizes," if the document tray 30 is in the lowered position (FIG. 6) (S203 NO), the reader CPU 301 waits until a document is placed while maintaining the document tray 30 in the lowered position (S205). In this case, if the document presence sensor 10 is turned ON due to a new document being placed on the document tray 30 (S205 YES), it is confirmed whether or not the mixed scanning of non-standard sizes mode is selected (S206). If the mixed scanning of non-standard sizes mode is selected (S206 YES), the document tray 30 is moved from the lowered position to the standby position and placed on standby (S207).

[0083] As a result, when documents are placed after selecting mixed scanning of non-standard sizes, the document tray 30 does not move to the raised position but stops at the standby position, so that mixed documents including non-standard sizes can be easily repositioned or added.

[0084] If the document is placed on the document tray 30 and non-standard size document reading is not selected (S201 NO, S205 YES, S206 NO), the reader CPU 301 moves the document tray 30 to the raised position (S208) and waits until the user selects to start reading via the operation unit 416 (S209).

[0085] When the user issues a command to start reading (S209 YES), the reader CPU 301 checks whether the document tray 30 is in the raised position (S210). If the document tray 30 is in the raised position when the command to start reading is received (S210 YES), the feed roller 1 and other elements are driven while the document tray 30 is maintained in the raised position. As a result, the documents placed on the document tray 30 are fed one by one, and image information is read (S212).

[0086] On the other hand, if the document tray 30 is not in the raised position when the instruction to start reading is received (S210NO, i.e., if it is in the standby position or the lowered position), the document tray 30 is moved to the raised position (S211) and then the feed roller 1 and the like are started to be driven. Then, image information is read from the document transported along the transport path in the ADF 200 (S212).

[0087] When all the documents placed on the document tray 30 have been transported and reading of the image information has been completed (S213 YES), the reader CPU lowers the document tray 30 from the raised position (S214) and returns to S201 to continue the process.

[0088] By controlling in accordance with the above flowchart, when the mode for reading mixed documents of irregular sizes is selected, document tray 30 waits in the standby position until an instruction to start reading is given, making it easier to set mixed documents including irregular sizes.

[0089] (Other embodiments) The embodiment of the present technology is not necessarily limited to the above-described examples. For example, an image reading device may be connected to a PC, and a configuration may be used in which mixed scanning of non-standard sizes can be instructed from the PC screen.

[0090] In addition, in controlling the lifting and lowering of the document tray 30, instead of detecting the position of the document tray 30 by sensors (314, 315), the position of the document tray 30 may be obtained, for example, by counting the number of drive pulses of a pulse motor that drives the lifting mechanism.

[0091] Moreover, the ADF used in the image reading device is one example of a sheet conveying device, and the above-mentioned embodiment may be applied to a sheet conveying device for other purposes (for example, a feeding device that feeds a sheet as a recording material to an image forming device body).The above-mentioned embodiment may be applied to an ADF that has only a document conveying function and does not include an image information reading unit such as the back side reading unit 202 (FIG. 4(b)) inside the ADF.

[0092] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions. [Explanation of symbols]

[0093] 1... Feeding means (feeding roller) / 10... Detection means (original presence / absence sensor) / 30... Loading section (original tray) / 150... Image reading device / 180... Image forming device / 200... Sheet conveying device (ADF) / 312... Lifting means (tray lifting motor) / 301... Control means (reader CPU) / 416... Operation section< / adf>

Claims

1. a loading section on which sheets are loaded; a detection unit for detecting a sheet loaded on the loading section; a feeding unit disposed above the stacking unit and configured to feed the sheets stacked on the stacking unit; a lifting means for lifting the stacking section between a first position where the sheets stacked on the stacking section contact the feeding means and a second position which is a lower limit position of a movement range of the stacking section; a control means for controlling the lifting means to move the loading unit to a third position between the first position and the second position; Equipped with When the control means moves the loading unit to the third position, the control means lowers the loading unit by a predetermined distance from the first position and stops the loading unit at the third position. A sheet conveying device comprising:

2. The control means moves the loading section from the second position to the third position based on the detection of the sheet by the detection means.

2. The sheet transport device according to claim 1.

3. the control unit moves the stacking unit from the first position to the second position based on a state in which the detection unit does not detect a sheet after the feeding unit starts feeding the sheet, 3. The sheet transport device according to claim 2.

4. the third position is a position where the document loaded on the loading section does not contact the feeding means; 4. The sheet transport device according to claim 1, wherein the sheet transport device is a sheet conveying device.

5. A raised position detection sensor is provided to detect when the loading section is in the first position, The third position is a position where the lifted position detection sensor does not detect the loading unit.

5. The sheet transport device according to claim 1, wherein the sheet transport device is a sheet conveying device.

6. A lowering position detection sensor is provided to detect when the loading section is in the second position, When the feeding of the sheets stacked on the stacking portion is completed, the control unit lowers the stacking portion from the first position to the second position.

6. The sheet transport device according to claim 1, wherein the sheet transport device is a sheet conveying device.

7. A sheet conveying device according to any one of claims 1 to 6, a reading means for reading image information from the sheet conveyed by the sheet conveying device; An image reading device comprising:

8. The image reading device according to claim 7 ; an image forming means for forming an image on a recording material based on the image information read by the image reading device; An image forming apparatus comprising:

Images