JP6992345B2 - Paper feed device and image formation system - Google Patents

Description

The present disclosure relates to a paper feed device and an image forming system.

Conventionally, some image forming apparatus such as a copier or a printer form a high quality image on a print medium according to a profile including image forming conditions. In such a profile, the type of print medium, the size of the print medium, the process adjustment, and the like are set in detail. As the process adjustment, for example, the temperature of the belt of the fixing portion and the like are set, and different settings are made depending on the print medium. Therefore, there has been proposed a method of discriminating a print medium before setting it in a tray (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-125237

However, in the prior art as described in Patent Document 1, the print medium is discriminated outside the tray, and the profile corresponding to the print medium set by the user's operation is selected according to the discrimination result. Therefore, due to an erroneous operation by the user, the print medium set in the tray may differ from the print medium corresponding to the profile selected by the user's operation. In this case, since the profile is selected according to the print medium different from the print medium set in the tray, there is a possibility that a high quality image cannot be formed on the print medium set in the tray.

The present disclosure has been made in view of such circumstances, and is intended to enable high-quality images to be formed on a print medium set in a tray.

The paper feed device, which is the first aspect of the present disclosure, has an elevating tray on which a print medium is placed, and a vent provided above the elevating tray, and has a vent, and the inside is controlled to a negative pressure state. A feeding belt provided at a position covering the vents of the ventilation duct, having a plurality of through holes, and capable of transporting the print medium adsorbed by the plurality of through holes in the negative pressure state. The feed belt has an upper sensor that detects one of the front and back surfaces of the print medium, and a lower sensor that is provided below the upper sensor and detects any one of the front and back surfaces of the print medium. The control unit includes a media detection sensor for detecting the feature amount of the print medium adsorbed on the print medium, a control unit for controlling the elevating tray, the feed belt, and the media detection sensor, and the control unit is the feed belt. The media detection sensor is made to detect the feature amount of the print medium in a state where the print medium adhering to the print medium is one sheet.

Further, the upper sensor is provided around the lower end side of the feed belt, the lower sensor is movably provided below the ventilation duct and the feed belt, and the control unit is provided with the control unit. When the print medium is attracted to the feed belt, it is preferable to move the lower sensor to a position facing the upper sensor.

Further, it is preferable that the elevating tray is further provided with an elevating motor capable of elevating the elevating tray, and the control unit lowers the elevating tray by the elevating motor before moving the lower sensor.

Further, a transport detection sensor provided behind the feed belt and on the transport path of the print medium to detect the passage of the print medium is further provided, and the feed belt is directed toward the transport detection sensor. The print medium can be conveyed freely, the upper sensor is provided behind the feed belt and above the transport path of the print medium, and the lower sensor is behind the feed belt and on the print medium. The control unit is provided below the transport path and faces the upper sensor, and when the print medium is detected by the transport detection sensor, the upper sensor and the lower sensor indicate the print medium. It is preferable to detect the feature amount of.

Further, when the control unit detects the feature amount of the print medium by the upper sensor and the lower sensor, it is preferable that the print medium is returned to the elevating tray by the feed belt.

Further, a drive roller that is wound around the feed belt to drive the feed belt, a driven roller that is wound around the feed belt and follows the drive of the feed belt, and a rotary drive of the drive roller. The drive motor is further provided with a drive motor for controlling the drive current, and the drive current is variably set according to the feature amount of the print medium. The control unit is printed by the feed belt. When the medium is conveyed to the detection positions of the upper sensor and the lower sensor, it is preferable to set the drive current to the maximum current in the allowable current range.

Further, the drive speed of the drive motor is variably set according to the feature amount of the print medium, and the control unit uses the feed belt to set the print medium on the upper sensor and the lower side. When transporting to the detection position of the sensor, it is preferable to set the drive speed to the minimum speed in the allowable speed range.

Further, an intake fan provided at the end of the ventilation duct to control the inside of the ventilation duct to the negative pressure state, and the ventilation duct provided inside the ventilation duct and flowing from the outside to the inside of the ventilation port. The control unit further includes an air volume detection sensor for detecting the air volume of the air volume, and the control unit is based on the air permeability of the print medium obtained from the air volume of the ventilation duct detected by the air volume detection sensor, and the type of the print medium. Is preferred.

Further, it is preferable that the control unit reduces the air volume of the intake fan when the print medium is adsorbed on the feed belt.

Further, a suction sensor provided on the lower end side of the feed belt and detecting whether or not the print medium is sucked on the feed belt is further provided, and the control unit is provided with the suction sensor to make the print medium stick to the feed belt. It is preferable to increase the air volume of the intake fan until it is detected that the feed belt is adsorbed.

Further, a horizontal regulation guide provided on each side surface of the elevating tray to guide the side surface of the print medium, and a handling fan provided on the horizontal regulation guide to blow out the handling air for handling the printing medium are further provided. When the control unit detects that the print medium is adsorbed on the feed belt by the adsorption sensor, it is preferable to stop the drive of the handling fan.

Further, it is preferable that the control unit increases the air volume of the handling fan until the suction sensor detects that the print medium is adsorbed on the feed belt.

Further, a double feed detection sensor for detecting whether or not the print medium is double feed is further provided, and the double feed detection sensor is provided around the lower end side of the feed belt to transmit ultrasonic waves. The control unit includes a unit and a reception unit that faces the transmission unit and receives the ultrasonic waves transmitted by the transmission unit. The control unit has a print medium between the transmission unit and the reception unit. It is preferable to determine whether or not the number of print media adsorbed on the feed belt is one, based on the reception intensity of the ultrasonic waves received by the receiving unit while passing through.

The image forming system according to the second aspect of the present disclosure includes an image forming device described above and an image forming device for forming an image on the print medium based on the feature amount of the print medium. It is a system.

According to the first aspect and the second aspect of the present disclosure, a high quality image can be formed on a print medium set in a tray.

It is a figure which shows the whole structure example of the image formation system 1 in Embodiment 1 of this disclosure. It is a top view of the main part configuration example of the paper feed apparatus 7 in Embodiment 1 of this disclosure. It is a figure which shows an example of the standby state of the media detection sensor 111 in Embodiment 1 of this disclosure. It is a figure which shows an example of the detection state of the media detection sensor 111 in Embodiment 1 of this disclosure. It is a figure which shows the functional structure example of the control system of the image formation system 1 in Embodiment 1 of this disclosure. It is a flowchart explaining the control example in Embodiment 1 of this disclosure. It is sectional drawing of the main part composition example of the paper feed apparatus 7 in Embodiment 2 of this disclosure. It is a figure which shows the functional structure example of the control system of the image formation system 1 in Embodiment 2 of this disclosure. It is a flowchart explaining the control example in Embodiment 2 of this disclosure. It is a flowchart explaining the control example in Embodiment 3 of this disclosure. It is a flowchart explaining the control example in Embodiment 4 of this disclosure. It is a flowchart explaining the control example in Embodiment 5 of this disclosure. It is a top view of the main part configuration example of the paper feed apparatus 7 in Embodiment 6 of this disclosure. It is a figure which shows the mechanism configuration example of the control system of the image formation system 1 in Embodiment 6 of this disclosure. It is a flowchart explaining the control example in Embodiment 6 of this disclosure. It is a flowchart explaining the control example in Embodiment 7 of this disclosure. It is a flowchart explaining the control example in Embodiment 8 of this disclosure. It is a flowchart explaining the control example in Embodiment 9 of this disclosure. It is a flowchart explaining the control example in Embodiment 10 of this disclosure.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the following embodiments.

Embodiment 1.
FIG. 1 is a diagram showing an overall configuration example of the image forming system 1 according to the first embodiment of the present disclosure. FIG. 2 is a top view of a configuration example of a main part of the paper feed device 7 according to the first embodiment of the present disclosure. FIG. 3 is a diagram showing an example of a standby state of the media detection sensor 111 according to the first embodiment of the present disclosure. FIG. 4 is a diagram showing an example of a detection state of the media detection sensor 111 according to the first embodiment of the present disclosure. FIG. 5 is a diagram showing a functional configuration example of the control system of the image forming system 1 according to the first embodiment of the present disclosure. The image forming system 1 includes a paper feeding device 7 and an image forming device 3. The image forming apparatus 3 is arranged after the paper feeding apparatus 7. The image forming apparatus 3 is an apparatus for forming a color image on the print medium P by an intermediate transfer method utilizing an electrophotographic process technique. The image forming apparatus 3 primary transfers the Y (yellow), M (magenta), C (cyan), and K (black) color toner images formed on the photoconductor 413 to the intermediate transfer belt of the intermediate transfer unit 42. .. Each color toner image primaryly transferred to the intermediate transfer belt is superposed on four colors and then secondarily transferred to the print medium P to form an image on the print medium P. The image forming apparatus 3 adopts a tandem method. The tandem method is a method in which the photoconductors 413 corresponding to the four colors of YMCK described above are arranged in series in the traveling direction of the intermediate transfer belt, and the toner images of each color are sequentially transferred to the intermediate transfer belt in one procedure.

The image forming apparatus 3 includes an image reading unit 10, an operation display unit 20, an image processing unit 30, an image forming unit 40, a paper transport unit 50, a fixing unit 60, and a control unit 90. The control unit 90 includes a CPU, a ROM, a RAM, a storage unit (not shown), and the like. The CPU reads a program from the ROM according to the processing content, expands it into the RAM, and controls the operation of the image forming apparatus 3 in cooperation with the expanded program. The storage unit is realized by a non-volatile semiconductor memory such as a flash memory or a hard disk drive, and various data are stored. Various data stored in the storage unit are referred to when the CPU controls the operation of the image forming apparatus 3. The paper feeding device 7 includes a control unit 91 similar to that of the image forming device 3, and the control unit 91 controls the operation of the paper feeding device 7.

The image reading unit 10 includes an automatic document feeding device 11, a document image scanning device 12, and the like. The automatic document feeding device 11 is referred to as an ADF (Auto Document Feeder). The automatic document feeding device 11 conveys the documents placed on the document tray by the conveying mechanism and sends them out to the document image scanning device 12. The automatic document feeding device 11 can continuously read images of a large number of originals placed on a document tray. When the automatic document feeding device 11 continuously reads images of a large number of originals, the automatic document feeding device 11 can read both sides of each original by the paper reversing mechanism. The document image scanning device 12 optically scans the document conveyed on the contact glass from the automatic document feeding device 11 or the document placed on the contact glass. The document image scanning device 12 reads the document image formed on the document by forming an image of the reflected light from the document by optical scanning on the light receiving surface of the CCD sensor. The image reading unit 10 generates input image data of the original image based on the scanning result by the original image scanning device 12. The input image data is supplied to the image processing unit 30, and the image processing unit 30 executes preset image processing.

The image processing unit 30 includes a circuit that performs digital image processing on the input image data according to various profiles set by initial setting, user setting, or the like. In the profile, the type of the print medium P, the size of the print medium P, the process adjustment, and the like are set in detail. The process adjustment is, for example, the setting of the temperature of the fixing belt of the fixing unit 60 and the like, and is preferably set according to the print medium P and the user's request. The image processing unit 30 performs various correction processing such as gradation correction, color correction, shading correction, and compression processing on the input image data, for example. The image forming unit 40 performs various processes based on the input image data obtained by such various digital image processes. The image forming unit 40 forms an image with each colored toner of the Y component, the M component, the C component, and the K component based on the input image data.

The image forming unit 40 includes an exposure device 411, a developing device 412, a photoconductor 413, a charging device 414, a drum cleaning device 415, and the like. The photoconductor 413 is charged by the corona discharge of the charging device 414. When the exposure apparatus 411 irradiates the photoconductor 413 with the laser beam corresponding to the image of each color component, an electrostatic latent image of each color component is formed. When the developing device 412 adheres the toner of each color component to the surface of the photoconductor 413, the electrostatic latent image is visualized and the toner image is formed.

The drum cleaning device 415 removes the transfer residual toner remaining on the surface of the photoconductor 413 after the primary transfer. The intermediate transfer unit 42 includes an intermediate transfer belt, a primary transfer roller, a secondary transfer roller, and the like. The primary transfer nip formed by pressure contact between the intermediate transfer belt and the primary transfer roller transfers a toner image from the photoconductor 413 to the intermediate transfer belt. The secondary transfer nip formed by pressure contacting the intermediate transfer belt and the secondary transfer roller transfers the toner image from the intermediate transfer belt to the printing medium P. The fixing unit 60 forms an image on the print medium P by heating and pressurizing the toner image transferred to the print medium P. The paper transport unit 50 includes a paper feed unit 51, a paper discharge unit 52, a transport path unit 53, and the like.

The paper feed device 7 separates and ejects the print medium P for each sheet. The print medium P discharged from the paper feed device 7 is conveyed to the image forming apparatus 3. As an example, the paper feeding device 7 includes drawer trays 72_u, 72_m, 72_l inside the housing 71, and includes a paper passing path 101. The drawer trays 72_u, 72_m, and 72_l each have the same configuration, and when they are generically referred to, they are referred to as a drawer tray 72. The drawer tray 72 includes an elevating tray 73, a ventilation duct 77, a feeding belt 78, and a media detection sensor 111. A print medium P is placed on the elevating tray 73, and the elevating tray 73 can be elevated by an elevating motor 763. A rear regulation guide 75, a lateral regulation guide 74, and a front regulation guide 76 are provided around the elevating tray 73. The rear regulation guide 75 guides the rear end side of the print medium P. The lateral regulation guide 74 guides the side surface of the print medium P. The front regulation guide 76 guides the front end side of the print medium P. The lateral regulation guide 74 has an outlet 741. The lateral regulation guide 74 is provided with a handling fan 742. The handling fan 742 is rotationally driven by the PWM control circuit 912 to blow out the handling air that handles the print medium P. Specifically, the lateral regulation guide 74 can handle the print medium P by blowing out the handling air generated by the rotational drive of the handling fan 742 from the outlet 741. The pre-regulation guide 76 has an outlet 761. The front regulation guide 76 is provided with a levitation fan 762. The levitation fan 762 is rotationally driven by the PWM control circuit 913 to blow out levitation air that levitates the print medium P. Specifically, the front regulation guide 76 can float the print medium P by blowing out the floating air generated by the rotational drive of the floating fan 762 from the outlet 761.

The ventilation duct 77 is provided above the elevating tray 73, has a ventilation port 771, and the inside is controlled to a negative pressure state. An intake fan 772 is provided at the end of the ventilation duct 77. The intake fan 772 is rotationally driven by the PWM control circuit 911 to control the inside of the ventilation duct 77 to a negative pressure state. The feed belt 78 is provided at a position that covers the ventilation port 771 of the ventilation duct 77, has a plurality of through holes 781, and is capable of transporting the print medium P that is adsorbed by the plurality of through holes 781 in a negative pressure state. .. The feed belt 78 is wound around the drive roller 81 and the driven roller 82. The drive roller 81 drives the feed belt 78. Specifically, the drive motor 811 controls the rotational drive of the drive roller 81 to drive the drive roller 81, whereby the transfer of the print medium P by the feed belt 78 is started, and the driven roller 82 feeds. It follows the drive of the feed belt 78. In the drive motor 811, the drive current or the drive speed is variably set according to the feature amount of the print medium P.

The media detection sensor 111 detects the feature amount of the print medium P adsorbed on the feed belt 78. The feature amount of the print medium P may be any parameter as long as it can specify the print medium P, and is, for example, a paper type, a basis weight, a paper thickness, a rigidity, a whiteness, and the like. The media detection sensor 111 includes an upper sensor 111a and a lower sensor 111b. The upper sensor 111a detects either the front or the back of the print medium P. The lower sensor 111b is provided below the upper sensor 111a and detects either the front or the back of the print medium P. Specifically, as shown in FIGS. 2 to 4, the upper sensor 111a is provided around the lower end side of the feed belt 78. The lower sensor 111b is movably provided at a position below the ventilation duct 77 and the feeding belt 78. The lower sensor 111b is provided on the lateral regulation guide 74 by the mounting portion 112, and can be moved to a position facing the upper sensor 111a depending on the conditions. The mounting portion 112 is connected to a drive component such as a solenoid via, for example, an actuator (not shown). Therefore, after the print medium P is attracted to the feed belt 78, the lower sensor 111b can be made to face the upper sensor 111a by operating the driving component thereof. The media detection sensor 111 is a pair of an upper sensor 111a and a lower sensor 111b, and can be configured as, for example, a capacitance type sensor. In the case of a capacitance type sensor, since each of the upper sensor 111a and the lower sensor 111b is an electrode, the capacitance value of the electrode is detected by inserting an object to be detected such as a print medium P between the electrodes. Then, the feature amount of the print medium P may be obtained from the detection result.

In one example of FIGS. 2 to 4, the mounting portion 112 is also provided with a double feed detection sensor 121. The double feed detection sensor 121 detects whether or not the print medium P is double feed. The double feed detection sensor 121 includes a transmission unit 121a and a reception unit 121b. The transmission unit 121a is provided around the lower end side of the feed belt 78 and transmits ultrasonic waves. The receiving unit 121b faces the transmitting unit 121a and receives the ultrasonic waves transmitted by the transmitting unit 121a. Specifically, the receiving unit 121b can detect the number of double-fed print media P by receiving the transmission energy in which the energy of the ultrasonic waves transmitted by the transmitting unit 121a passes through the print medium P. can. That is, the control unit 91 adsorbs the print medium to the feed belt 78 based on the reception intensity of the ultrasonic waves received by the reception unit 121b while the print medium P passes between the transmission unit 121a and the reception unit 121b. It is determined whether or not P is one.

The suction sensor 122 includes a light emitting unit 122a, a light receiving unit 122b, and a flap 122c. The flap 122c is provided between the drive roller 81 and the driven roller 82. The light emitting unit 122a and the light receiving unit 122b are provided in a facing relationship, and a part of the flap 122c can pass between them. The light emitted from the light emitting unit 122a is incident on the light receiving unit 122b. The light receiving unit 122b detects the intensity of the light incident from the light emitting unit 122a. When the print medium P is not attracted to the feed belt 78, a part of the flap 122c protrudes below the lower end side of the feed belt 78, and a part of the flap 122a protrudes below the lower end side of the feed belt 78, and a part of the flap 122a is a light emitting portion 122a. It is a position that does not block the light from the light receiving unit 122b. On the other hand, when the print medium P is attracted to the feed belt 78, a part of the flap 122c is pushed up to the lower end side of the feed belt 78, and the other part is the light emitting portion 122a, as shown in FIG. It is a position to block the light from the light receiving unit 122b. Therefore, the adsorption sensor 122 can detect whether or not the print medium P is adsorbed on the feed belt 78 by detecting the intensity of light by the light receiving unit 122b.

The control unit 91 controls the elevating tray 73, the feed belt 78, and the media detection sensor 111. The control unit 91 causes the media detection sensor 111 to detect the feature amount of the print medium P in a state where the print medium P adsorbed on the feed belt 78 is one sheet. In the state where there is only one print medium P adsorbed on the feed belt 78, the print medium P between the upper sensor 111a and the lower sensor 111b is the highest among the print media P. It is equivalent to being paper P_t. When the print medium P is attracted to the feed belt 78, the control unit 91 moves the lower sensor 111b to a position facing the upper sensor 111a. When the top paper P_t is attracted to the feed belt 78, the control unit 91 lowers the elevating tray 73 by the elevating motor 763 before moving the lower sensor 111b. In the control unit 91, the print medium P attracted to the feed belt 78 based on the reception intensity of the ultrasonic waves received by the reception unit 121b while the print medium P passes between the transmission unit 121a and the reception unit 121b. It is determined whether or not it is one.

FIG. 6 is a flowchart illustrating a control example according to the first embodiment of the present disclosure. The processing of steps S16 to S22 corresponds to the pre-transportation detection processing. Further, in the following description of each process, an example of the case where the print medium P is paper will be described. In step S11, the control unit 91 sets the handling fan 742 to the ON state. In step S12, the control unit 91 sets the levitation fan 762 to the ON state. In step S13, the control unit 91 sets the intake fan 772 to the ON state. In step S14, the control unit 91 determines whether or not a certain time has elapsed. When the control unit 91 determines that a certain time has elapsed (step S14; Y), the control unit 91 shifts to the process of step S15. When the control unit 91 determines that a certain time has not elapsed (step S14; N), the control unit 91 repeats the process of step S14. In step S15, the control unit 91 determines whether or not the suction sensor 122 has detected the paper. When the control unit 91 determines that the suction sensor 122 has detected the paper (step S15; Y), the control unit 91 shifts to the process of step S16. When the control unit 91 determines that the suction sensor 122 does not detect the paper (step S15; N), the control unit 91 returns to the process of step S14.

In step S16, the control unit 91 lowers the elevating tray 73. In step S17, the control unit 91 moves the lower sensor 111b in the media detection sensor 111 to a position facing the upper sensor 111a. In step S18, the control unit 91 determines whether or not the detected paper is one sheet. When the control unit 91 determines that the detected paper is one sheet (step S18; Y), the control unit 91 shifts to the process of step S22, and in step S22, the media detection sensor 111 detects the feature amount of the paper. And end the process. When the control unit 91 determines that the number of detected sheets is not one (step S18; N), the control unit 91 shifts to the process of step S19. In step S19, the control unit 91 sets the handling fan 742 to the off state. In step S20, the control unit 91 sets the levitation fan 762 to the off state. In step S21, the control unit 91 sets the intake fan 772 to the off state, and returns to the process of step S11. That is, if the number of sheets detected by the suction sensor 122 is not one, the control unit 91 returns the paper sucked on the feed belt 78 to the elevating tray 73, and the paper detected by the suction sensor 122 is 1. The process of adsorbing the paper to the feeding belt 78 is repeated until the number of sheets is reached.

From the above description, according to the present embodiment, when the number of print media P adsorbed on the feed belt 78 is one, the feature amount of the print medium P is detected. Therefore, since the print medium P set in the elevating tray 73 and the print medium P corresponding to the detected feature amount are the same, the profile should be selected according to the print medium P set in the elevating tray 73. Can be done. Therefore, a high-quality image can be formed on the print medium P set in the elevating tray 73.

Further, according to the present embodiment, when the feature amount of the print medium P is detected with one print medium P adsorbed on the feed belt 78, the upper sensor 111a and the lower sensor are executed. The print medium P between the 111b and the print medium P is determined. Therefore, as the feature amount of the print medium P, one print medium P corresponding to the top paper P_t is detected. Therefore, the print medium P can be accurately specified, and the print medium P is not wasted.

Further, according to the present embodiment, when the print medium P is attracted to the feed belt 78, the lower sensor 111b is moved to a position facing the upper sensor 111a. Therefore, the feature amount of the print medium P can be detected without transporting the print medium P by the feed belt 78. Therefore, various air volumes for handling the print medium P on the elevating tray 73 and adsorbing them on the feed belt 78 can be appropriately controlled, and various set values for process adjustment of the image forming apparatus 3 on the rear stage side can be set to appropriate values. Can be set.

Further, according to the present embodiment, when the print medium P is attracted to the feed belt 78, the elevating tray 73 is lowered by the elevating motor 763 before moving the lower sensor 111b. Therefore, the lower sensor 111b can be moved after the feed belt 78 and the print medium P mounted on the elevating tray 73 are separated from each other. Therefore, since it is possible to prevent the lower sensor 111b from interfering with the print medium P mounted on the elevating tray 73, it is possible to accurately detect the feature amount of the print medium P.

Further, according to the present embodiment, the print medium P is attracted to the feeding belt 78 based on the reception intensity of the ultrasonic waves received by the receiving unit 121b while passing between the transmitting unit 121a and the receiving unit 121b. It is determined whether or not the number of print media P is one. Therefore, it is possible to determine whether or not the print medium P is double-fed and conveyed. Therefore, the media detection sensor 111 can reliably detect the feature amount of the print medium P when the print medium P is one sheet.

Embodiment 2.
In the second embodiment, the same reference numerals are given to the same configurations as those in the first embodiment, and the description thereof will be omitted. The second embodiment detects the feature amount of the print medium P by transporting the print medium P as compared with the first embodiment which executes the pre-transport detection process for detecting the feature amount of the print medium P before transporting the print medium P. The difference is that the transport detection process is executed. FIG. 7 is a cross-sectional view of a configuration example of a main part of the paper feed device 7 according to the second embodiment of the present disclosure. FIG. 8 is a diagram showing a functional configuration example of the control system of the image forming system 1 according to the second embodiment of the present disclosure. As shown in FIG. 7, the transport detection sensor 123 is provided behind the feed belt 78 and on the transport path of the print medium P, and detects the passage of the print medium P. The transport detection sensor 123 is, for example, a photo sensor including a light receiving element and a light emitting element. In one example of FIG. 7, the light receiving element and the light emitting element are integrated into a reflective sensor, but a transmissive sensor in which the light receiving element and the light emitting element are separated from each other may be used. The feed belt 78 is capable of transporting the print medium P toward the transport detection sensor 123. The upper sensor 111a is provided behind the feed belt 78 and above the transport path of the print medium P. The lower sensor 111b is provided behind the feed belt 78 and below the transport path of the print medium P, facing the upper sensor 111a. When the print medium P is detected by the transport detection sensor 123, the control unit 91 causes the upper sensor 111a and the lower sensor 111b to detect the feature amount of the print medium P.

FIG. 9 is a flowchart illustrating a control example according to the second embodiment of the present disclosure. Since the processes of steps S41 to S45 and steps S50 to S54 are the same as the processes of steps S11 to S15 and steps S18 to S22, the description thereof will be omitted. The processing of steps S46 to S54 corresponds to the transport detection processing. In step S46, the control unit 91 sets the drive roller 81 for driving the feed belt 78 to the ON state. In step S47, the control unit 91 conveys the paper to the downstream side in the conveying direction. In step S48, the control unit 91 determines whether or not the transport detection sensor 123 has detected the paper. When the control unit 91 determines that the transport detection sensor 123 has detected the paper (step S48; Y), the control unit 91 shifts to the process of step S49. When the control unit 91 determines that the transport detection sensor 123 does not detect the paper (step S48; N), the control unit 91 returns to the process of step S47. In step S49, the control unit 91 sets the drive roller 81 for driving the feed belt 78 to the off state.

From the above description, according to the present embodiment, when the print medium P is detected by the transport detection sensor 123, the feature amount of the print medium P is detected by the upper sensor 111a and the lower sensor 111b. Therefore, the feature amount of the print medium P can be detected without providing a member for moving the lower sensor 111b. Therefore, since the configuration of the media detection sensor 111 can be simplified, the print medium P can be specified at low cost.

Embodiment 3.
In the third embodiment, the same reference numerals are given to the same configurations as those of the first and second embodiments, and the description thereof will be omitted. The third embodiment is different from the first embodiment in that the transport detection process is performed, and the second embodiment is different from the second embodiment in that the paper is returned to the elevating tray 73 in the transport detection process. FIG. 10 is a flowchart illustrating a control example according to the third embodiment of the present disclosure. Since the processing of steps S71 to S84 is the same as the processing of steps S41 to S54, the description thereof will be omitted. The processing of steps S76 to S90 corresponds to the transport detection processing. In step S85, the control unit 91 conveys the paper to the upstream side in the conveying direction. In step S86, the control unit 91 determines whether or not the amount of movement of the paper is the same as the amount of movement to the downstream side in the transport direction. When the control unit 91 determines that the movement amount of the paper is the same as the movement amount to the downstream side in the transport direction (step S86; Y), the control unit 91 shifts to the process of step S87. When the control unit 91 determines that the amount of movement of the paper is not the same as the amount of movement to the downstream side in the transport direction (step S86; N), the control unit 91 returns to the process of step S85. Specifically, the drive motor 811 is rotated in the direction opposite to the transport direction in which the paper is transported to the transport detection sensor 123 so that the distance is the same as when the paper is transported to the transport detection sensor 123. More specifically, the control unit 91 outputs a rotation direction switching signal to the drive motor 811 to switch the rotation direction in the opposite direction, and then drives the motor with the same number of clocks as when the paper is conveyed to the transfer detection sensor 123. Output to 811. Although a control example in which the drive motor 811 is a stepping motor has been described, the present invention is not particularly limited thereto. In step S87, the control unit 91 sets the drive roller 81 for driving the feed belt 78 to the off state. In step S88, the control unit 91 sets the handling fan 742 to the off state. In step S89, the control unit 91 sets the levitation fan 762 to the off state. In step S90, the control unit 91 sets the intake fan 772 to the off state and ends the process.

From the above description, according to the present embodiment, when the feature amount of the print medium P is detected by the upper sensor 111a and the lower sensor 111b, the print medium P is returned to the elevating tray 73 by the feed belt 78. Therefore, since the print medium P returned to the elevating tray 73 is conveyed from the elevating tray 73 again at the time of image formation, the print medium P can be specified without wasting even one print medium P.

Embodiment 4.
In the fourth embodiment, the same reference numerals are given to the same configurations as those of the first to third embodiments, and the description thereof will be omitted. The fourth embodiment is different from the first embodiment in that it is a transport detection process, and is different from the second embodiment in that the drive current of the drive motor 811 is maximized. The difference is that the drive current is maximized and the process of returning the paper to the elevating tray 73 is not included. FIG. 11 is a flowchart illustrating a control example according to the fourth embodiment of the present disclosure. Since the processes of steps S101 to S106 and steps S108 to S115 are the same as the processes of steps S41 to S54, the description thereof will be omitted. The process of step S107 is preferably performed before the process of transporting the paper in step S108 to the downstream side in the transport direction. The processing of steps S106 to S115 corresponds to the transport detection processing. In step S107, the control unit 91 sets the drive current of the drive motor 811 that controls the rotational drive of the drive roller 81 to the maximum current in the allowable current range. The allowable current range is determined based on the specifications of the drive motor 811.

From the above description, according to the present embodiment, when the print medium P is conveyed to the detection positions of the upper sensor 111a and the lower sensor 111b by the feed belt 78, the drive current is set to the maximum current in the allowable current range. .. Therefore, even when the print medium P having unknown characteristics is conveyed, the print medium P can be safely conveyed because the drive current is set to the maximum current.

Embodiment 5.
In the fifth embodiment, the same reference numerals are given to the same configurations as those of the first to fourth embodiments, and the description thereof will be omitted. The fifth embodiment is different from the first embodiment in that it is a transport detection process, is different from the second and fourth embodiments in that the drive speed of the drive motor 811 is minimized, and is a drive motor as compared with the third embodiment. The difference is that the drive speed of the 811 is minimized and the process of returning the paper to the elevating tray 73 is not included. FIG. 12 is a flowchart illustrating a control example according to the fifth embodiment of the present disclosure. Since the processes of steps S131 to S136 and steps S138 to S145 are the same as the processes of steps S41 to S54, the description thereof will be omitted. The process of step S137 is preferably performed before the process of transporting the paper in step S138 to the downstream side in the transport direction. The processing of steps S136 to S145 corresponds to the transport detection processing. In step S137, the control unit 91 sets the drive speed of the drive motor 811 that controls the rotational drive of the drive roller 81 to the minimum speed in the allowable speed range. The allowable speed range is determined based on the specifications of the drive motor 811.

From the above description, according to the present embodiment, when the print medium P is conveyed to the detection positions of the upper sensor 111a and the lower sensor 111b by the feed belt 78, the drive speed is set to the minimum speed in the allowable speed range. .. Therefore, even when the print medium P having unknown characteristics is conveyed, the print medium P can be safely conveyed because the drive speed is set to the minimum speed.

Embodiment 6.
In the sixth embodiment, the same reference numerals are given to the same configurations as those of the first to fifth embodiments, and the description thereof will be omitted. The sixth embodiment is different from the first to fifth embodiments in that the feature amount of the paper is obtained based on the air permeability. Air permeability is used as the degree to which air passes through in the thickness direction of the paper per unit time. FIG. 13 is a top view of a configuration example of a main part of the paper feed device 7 according to the sixth embodiment of the present disclosure. FIG. 14 is a diagram showing a mechanism configuration example of the control system of the image forming system 1 according to the sixth embodiment of the present disclosure. As shown in FIG. 13, the air volume detection sensor 124 is provided inside the ventilation duct 77 and detects the air volume of the ventilation duct 77 flowing from the outside to the inside of the ventilation port 771. The air volume detection sensor 124 is composed of, for example, a flow rate sensor based on a thermal type, a Coriolis type, a Karman vortex type, or the like, and detects the air volume transmitted through the paper when the paper is adsorbed on the feed belt 78. FIG. 15 is a flowchart illustrating a control example according to the sixth embodiment of the present disclosure. Since the processing of steps S161 to S169 is the same as the processing of steps S11 to S15 and steps S18 to S21, the description thereof will be omitted. The processing of steps S166 to S172 corresponds to the air permeability calculation processing. In step S170, the control unit 91 causes the air volume detection sensor 124 to detect the air volume of the ventilation duct 77. In step S171, the control unit 91 obtains the air permeability of the paper from the air volume of the ventilation duct 77. In step S172, the control unit 91 identifies the type of paper based on the air permeability of the paper, and ends the process. It should be noted that a table may be generated in which the air permeability of the paper and the feature amount of the paper corresponding to the air permeability of the paper are associated with each other, and the type of the paper may be specified based on the table.

From the above description, according to the present embodiment, the type of the print medium P is specified based on the air permeability of the print medium P obtained from the air volume of the ventilation duct 77 detected by the air volume detection sensor 124. Therefore, it is particularly effective for identifying coated base paper or kraft paper.

Embodiment 7.
In the seventh embodiment, the same reference numerals are given to the same configurations as those of the first to sixth embodiments, and the description thereof will be omitted. The seventh embodiment is different from the first to sixth embodiments in that the air volume of the intake fan 772 is reduced before the feature amount detection process. FIG. 16 is a flowchart illustrating a control example according to the seventh embodiment of the present disclosure. Since the processing of steps S191 to S195 is the same as the processing of steps S11 to S15, the description thereof will be omitted. The processing of steps S197 to S201 corresponds to the feature amount detection processing. The feature amount detection process is any of the air permeability calculation process, the pre-transport detection process, and the transport detection process. In step S196, the control unit 91 reduces the air volume of the intake fan 772. It is difficult to set the air volume of the intake fan 772 to the optimum air volume because the characteristic amount of the paper is not known and the paper cannot be uniquely specified. Therefore, the air volume of the intake fan 772 may be, for example, about 80% of the air volume when the paper is adsorbed on the feed belt 78. In step S197, the control unit 91 determines whether or not to obtain the air permeability. When the control unit 91 determines that the air permeability is to be obtained (step S197; Y), the control unit 91 shifts to the process of step S198, and in step S198, the air permeability calculation process is executed and the process is terminated. When the control unit 91 determines that the air permeability is not obtained (step S197; N), the control unit 91 shifts to the process of step S199. In step S199, the control unit 91 determines whether or not to execute the detection of the feature amount of the paper before the transfer. When the control unit 91 determines that the detection of the feature amount of the paper is executed before the transfer (step S199; Y), the control unit 91 shifts to the process of step S200, executes the pre-transfer detection process in step S200, and ends the process. Let me. When the control unit 91 determines that the detection of the feature amount of the paper is not executed before the transfer (step S199; N), the control unit 91 shifts to the process of step S201, executes the transfer detection process in step S201, and ends the process. Let me.

From the above description, according to the present embodiment, when the print medium P is adsorbed on the feed belt 78, the air volume of the intake fan 772 is reduced. Therefore, since it is possible to suppress the vertical fluttering of the print medium P, it is possible to reduce the noise when the feature amount of the print medium P is detected.

Embodiment 8.
In the eighth embodiment, the same reference numerals are given to the same configurations as those of the first to seventh embodiments, and the description thereof will be omitted. The eighth embodiment is different from the first to seventh embodiments in that the air volume of the intake fan 772 is increased until the paper is adsorbed on the feed belt 78. FIG. 17 is a flowchart illustrating a control example according to the eighth embodiment of the present disclosure. Since the processes of steps S221 to S223 and the processes of steps S225 to S228 are the same as the processes of steps S191 to S201, the description thereof will be omitted. The process of step S229 is executed when the control unit 91 determines in step S226 that the suction sensor 122 does not detect the paper. In step S224, the control unit 91 sets the air volume of the intake fan 772 to the minimum air volume. The minimum air volume is, for example, 20% of the maximum air volume. In step S229, the control unit 91 raises the air volume of the intake fan 772 and returns to the process of step S225. The air volume of the intake fan 772 is increased by, for example, 10%. That is, the air volume of the intake fan 772 may be increased stepwise.

From the above description, according to the present embodiment, the air volume of the intake fan 772 increases until it is detected by the suction sensor 122 that the print medium P is sucked on the feed belt 78. Therefore, since the print medium P can be attracted to the feed belt 78 so as not to damage the print medium P in the vertical direction, the feature amount of the print medium P can be accurately detected.

Embodiment 9.
In the ninth embodiment, the same reference numerals are given to the same configurations as those of the first to eighth embodiments, and the description thereof will be omitted. The ninth embodiment is different from the first to eighth embodiments in that the drive of the handling fan 742 is stopped. FIG. 18 is a flowchart illustrating a control example according to the ninth embodiment of the present disclosure. Since the processing of steps S251 to S257 and the processing of steps S259 and S260 are the same as the processing of steps S221 to S229, the description thereof will be omitted. The process of step S258 is executed before the feature amount detection process is executed in step S259. In step S258, the control unit 91 stops driving the handling fan 742.

From the above description, according to the present embodiment, when it is detected by the suction sensor 122 that the print medium P is sucked on the feed belt 78, the drive of the handling fan 742 is stopped. Therefore, since it is possible to suppress fluttering due to the wind blown from the side surface of the print medium P, it is possible to reduce noise when detecting the feature amount of the print medium P.

Embodiment 10.
In the tenth embodiment, the same reference numerals are given to the same configurations as those of the first to nine embodiments, and the description thereof will be omitted. The tenth embodiment is different from the first to ninth embodiments in that the air volume of the handling fan 742 is increased. FIG. 19 is a flowchart illustrating a control example according to the tenth embodiment of the present disclosure. Since the processes of steps S281 to S283 and the processes of steps S288 to S292 are the same as the processes of steps S251 to S253 and the processes of steps S255 to S259, the description thereof will be omitted. The processing of steps S284 to S287 and the processing of steps S293 to S296 will be described. In step S284, the control unit 91 determines whether or not the air volume of the handling fan 742 is set to the minimum air volume. When the control unit 91 determines that the air volume of the handling fan 742 is set to the minimum air volume (step S284; Y), the control unit 91 shifts to the process of step S285, and sets the handling minimum flag to 1 in step S285. When the control unit 91 determines that the air volume of the handling fan 742 is not set to the minimum air volume (step S284; N), the control unit 91 shifts to the process of step S286. In step S286, the control unit 91 determines whether or not the air volume of the intake fan 772 is set to the minimum air volume. When the control unit 91 determines that the air volume of the intake fan 772 is set to the minimum air volume (step S286; Y), the control unit 91 shifts to the process of step S287, and sets the intake minimum flag to 1 in step S287. When the control unit 91 determines that the air volume of the intake fan 772 is not set to the minimum air volume (step S286; N), the control unit 91 shifts to the process of step S288. In the above description, the minimum air volume of the handling fan 742 and the intake fan 772 is, for example, 20% of the maximum air volume.

In step S293, the control unit 91 determines whether or not the handling minimum flag is 1. When the control unit 91 determines that the handling minimum flag is 1 (step S293; Y), the control unit 91 shifts to the process of step S294, and in step S294, increases the air volume of the handling fan 742. The air volume of the handling fan 742 is increased by, for example, 10%. That is, the air volume of the handling fan 742 may be increased stepwise. When the control unit 91 determines that the handling minimum flag is not 1 (step S293; N), the control unit 91 shifts to the process of step S295. In step S295, the control unit 91 determines whether or not the intake minimum flag is 1. When the control unit 91 determines that the intake minimum flag is 1 (step S295; Y), the control unit 91 shifts to the process of step S296, increases the air volume of the intake fan 772 in step S296, and returns to the process of step S288. When the control unit 91 determines that the intake minimum flag is not 1 (step S295; N), the control unit 91 returns to the process of step S288.

From the above description, according to the present embodiment, the air volume of the handling fan 742 increases until it is detected by the suction sensor 122 that the print medium P is sucked on the feed belt 78. Therefore, since the print medium P can be attracted to the feed belt 78 so as not to damage the print medium P from the side surface, the feature amount of the print medium P can be accurately detected.

Although the image forming system 1 according to the present disclosure has been described above based on the embodiment, the present disclosure is not limited to this, and changes may be made without departing from the gist of the present disclosure.

For example, in the present embodiment, an example of uniquely specifying the print medium P by the thickness, basis weight, air permeability, etc. of the print medium P has been described, but the present invention is not particularly limited thereto. For example, the print medium P may be uniquely specified by the whiteness, the water content, the smoothness, the opacity, or the like of the print medium P. When detecting the thickness of the print medium P, a thickness sensor (not shown) may be used. The thickness sensor (not shown) may be any one in which two sensors are brought into contact with each other and the pressed amount of the sensor is converted into an electric signal for detection.

Further, in the present embodiment, an example of the double feed detection sensor 121 including the transmission unit 121a and the reception unit 121b in which the arrangement position of the reception unit 121b is movably provided has been described. Not limited. For example, the transmission unit 121a is provided behind the feeding belt 78 and above the transport path of the print medium P, and the reception unit 121b is behind the feed belt 78 and below the transport path of the print medium P. It may be provided so as to face the 121a.

The series of processes described above can be executed by hardware or software. When a series of processes are executed by software, the programs that make up the software can execute various functions by installing various programs on a computer that can execute various functions, from a recording medium that records the programs, or from a recording medium. , Is installed via the Internet, etc.

Further, in the exemplary embodiment shown in FIGS. 6, 9, 10 to 12, 15 to 19, the print medium P detected by the adsorption sensor 122 is premised on the control unit 91 executing the function of the feature amount detection process. It has a function of determining whether or not there is one sheet. As shown in FIGS. 1 to 4, 7 and 13, in some embodiments, the paper feed device 7 includes an elevating tray 73, a ventilation duct 77, a feed belt 78, a media detection sensor 111, and a control unit. The control unit 91 is provided with the 91, and the control unit 91 causes the media detection sensor 111 to detect the feature amount of the print medium P in a state where the print medium P adsorbed on the feed belt 78 is one sheet. It has the function of.

In the exemplary embodiment shown in FIGS. 2 to 6, the control unit 91 has a function of pre-transportation detection processing as one of the feature amount detection processing. In the exemplary embodiment shown in FIGS. 7 to 9, the control unit 91 has a function of transport detection processing as one of the feature amount detection processing. In the exemplary embodiment shown in FIG. 10, the control unit 91 further includes a function of returning the print medium P to the position of the elevating tray 73 in addition to the function of the transport detection process. In the exemplary embodiment shown in FIG. 11, the control unit 91 further includes a function of setting the drive current of the drive motor 811 when driving the feed belt 78 to the maximum current in the function of the transport detection process. In the exemplary embodiment shown in FIG. 12, the control unit 91 further includes a function of setting the drive speed of the drive motor 811 when driving the feed belt 78 to the minimum speed in the function of the transport detection process. In the exemplary embodiment shown in FIGS. 13 to 15, the control unit 91 has a function of air permeability calculation processing as one of the feature amount detection processing.

In the exemplary embodiment shown in FIGS. 16 to 19, the control unit 91 further includes a function of reducing the air volume of the intake fan 772 before executing the function of the feature amount detection process. In the exemplary embodiment shown in FIG. 16, the control unit 91 selectively executes any one of the air permeability calculation process, the pre-transport detection process, and the transfer detection process as the feature amount detection process according to the conditions. Further equipped with the function to do. In the exemplary embodiment shown in FIG. 17, the control unit 91 further includes a function of increasing the air volume of the intake fan 772 until the print medium P is adsorbed on the feed belt 78, in addition to the function of the feature amount detection process. .. In the exemplary embodiment shown in FIG. 18, the control unit 91 has a function of feature amount detection processing and a function of increasing the air volume of the intake fan 772 until the print medium P is adsorbed on the feed belt 78. It is further provided with a function of stopping the drive of the handling fan 742 before executing the function of the feature amount detection process. In the exemplary embodiment shown in FIG. 19, the control unit 91 has a function of feature amount detection processing, a function of increasing the air volume of the intake fan 772 until the print medium P is adsorbed on the feed belt 78, and a feature amount. In addition to the function of stopping the drive of the handling fan 742 before executing the detection processing function, it further has a function of increasing the air volume of the handling fan 742 until the print medium P is adsorbed on the feed belt 78.

1 Image forming system, 3 Image forming device, 10 Image reading unit 11 Automatic document paper feeding device, 12 Original image scanning device, 20 Operation display unit 30 Image processing unit, 40 Image forming unit, 411 Exposure device, 412 Development device 413 Photosensitivity Body, 414 Charging device, 415 Drum cleaning device 42 Intermediate transfer section, 50 Paper transport section, 51 Feed section, 52 Paper discharge section 53 Transport path section, 60 Fixing section 7 Feed device, 71 housing, 72,72_u, 72_m, 72_l Drawer tray 73 Lift tray, 74 Horizontal regulation guide, 741 outlet, 742 handling fan 75 Rear regulation guide, 76 Front regulation guide, 761 outlet, 762 Floating fan 763 Lift motor, 77 vent duct, 771 vent, 772 Intake fan 78 Feed belt, 781 through hole 81 Drive roller, 811 Drive motor, 82 Driven roller 90,91 Control unit, 911, 912,913 PWM control circuit 101 Paper path, 111 Media detection sensor 111a Upper sensor, 111b Lower sensor, 112 mounting part 121 double feed detection sensor, 121a transmitter, 121b receiver 122 adsorption sensor, 122a light emitting part, 122b light receiving part, 122c flap 123 transport detection sensor, 124 air volume detection sensor P print medium, P_t top paper

Claims (14)

An elevating tray on which the print medium is placed and
A ventilation duct provided above the elevating tray, having a ventilation port, and controlling the inside to a negative pressure state,
A feed belt provided at a position covering the ventilation port of the ventilation duct, having a plurality of through holes, and capable of transporting the print medium adsorbed by the plurality of through holes in the negative pressure state.
The feed belt has an upper sensor that detects one of the front and back surfaces of the print medium, and a lower sensor that is provided below the upper sensor and detects any one of the front and back surfaces of the print medium. A media detection sensor that detects the feature amount of the print medium adsorbed on the
A control unit that controls the elevating tray, the feed belt, and the media detection sensor.
Equipped with
The control unit
The media detection sensor is made to detect the feature amount of the print medium in a state where the print medium adsorbed on the feed belt is one sheet.
Paper feed device. The upper sensor
Provided around the lower end side of the feed belt,
The lower sensor
The arrangement position is movably provided below the ventilation duct and the feed belt.
The control unit
When the print medium is adsorbed on the feed belt, the lower sensor is moved to a position facing the upper sensor.
The paper feeding device according to claim 1 . An elevating motor that can elevate the elevating tray.
Further prepare
The control unit
Before moving the lower sensor, the elevating motor lowers the elevating tray.
The paper feeding device according to claim 2 . A transport detection sensor provided behind the feed belt and on the transport path of the print medium to detect the passage of the print medium.
Further prepare
The feed belt is
The print medium can be transported toward the transport detection sensor.
The upper sensor
Provided behind the feed belt and above the transport path of the print medium.
The lower sensor
It is provided behind the feed belt and below the transport path of the print medium, facing the upper sensor.
The control unit
When the print medium is detected by the transport detection sensor, the upper sensor and the lower sensor detect the feature amount of the print medium.
The paper feeding device according to claim 1 . The control unit
When the feature amount of the print medium is detected by the upper sensor and the lower sensor, the feed belt returns the print medium to the elevating tray.
The paper feeding device according to claim 4 . A drive roller that is wound around the feed belt and drives the feed belt,
A driven roller that is wound around the feed belt and follows the drive of the feed belt.
A drive motor that controls the rotational drive of the drive roller,
Further prepare
The drive motor
The drive current is variably set according to the feature amount of the print medium.
The control unit
When the print medium is conveyed to the detection positions of the upper sensor and the lower sensor by the feed belt, the drive current is set to the maximum current in the allowable current range.
The paper feeding device according to any one of claims 1 to 5 . The drive motor
The drive speed is variably set according to the feature amount of the print medium.
The control unit
When the print medium is conveyed to the detection positions of the upper sensor and the lower sensor by the feed belt, the drive speed is set to the lowest speed in the allowable speed range.
The paper feeding device according to claim 6 . An intake fan provided at the end of the ventilation duct and controlling the inside of the ventilation duct to the negative pressure state,
An air volume detection sensor provided inside the ventilation duct and detecting the air volume of the ventilation duct flowing from the outside to the inside of the ventilation port,
Further prepare
The control unit
The type of the print medium is specified based on the air permeability of the print medium obtained from the air volume of the ventilation duct detected by the air volume detection sensor.
The paper feeding device according to any one of claims 1 to 7 . The control unit
When the print medium is adsorbed on the feed belt, the air volume of the intake fan is reduced.
The paper feeding device according to claim 8 . A suction sensor provided on the lower end side of the feed belt and detecting whether or not the print medium is sucked on the feed belt.
Further prepare
The control unit
The air volume of the intake fan is increased until the suction sensor detects that the print medium is adsorbed on the feed belt.
The paper feeding device according to claim 8 or 9 . A horizontal regulation guide provided on each side surface of the elevating tray and guiding the side surface of the print medium,
A handling fan provided on the horizontal regulation guide to blow out the handling air that handles the printing medium, and
Further prepare
The control unit
When the suction sensor detects that the print medium is sucked on the feed belt, the drive of the handling fan is stopped.
The paper feeding device according to claim 10. The control unit
The air volume of the handling fan is increased until the suction sensor detects that the print medium is adsorbed on the feed belt.
The paper feeding device according to claim 11. A double feed detection sensor that detects whether or not the print medium is double feed,
Further prepare
The double feed detection sensor is
A transmission unit provided around the lower end side of the feed belt and transmitting ultrasonic waves,
A receiving unit that faces the transmitting unit and receives the ultrasonic wave transmitted by the transmitting unit.
Equipped with
The control unit
One printing medium is adsorbed on the feeding belt based on the reception intensity of the ultrasonic waves received by the receiving unit while the printing medium passes between the transmitting unit and the receiving unit. Judging whether or not
The paper feeding device according to any one of claims 1 to 12. The paper feeding device according to any one of claims 1 to 13 and the paper feeding device.
An image forming apparatus that forms an image on the printing medium based on the feature amount of the printing medium, and an image forming apparatus.
To prepare
Image formation system.

Images