JP2021134064A - Conveyance device and image formation device - Google Patents

Abstract

To provide an image formation device capable of preventing occurrence of jamming of a paper sheet caused by erroneous determination of a paper kind.SOLUTION: A printing condition suitability determination part 106, in requesting printing of an image, determines whether or not a printing condition determined by a user is suited for conveyance of an envelope. A paper processing decision part 107, when the printing condition determined by the user is not suited for conveyance of the envelope, does not cause a printing part to perform processing for the envelope regardless of a detection result of an ultrasonic sensor 117. Instead, as occurrence of double feeding, conveyance of a paper sheet is stopped.SELECTED DRAWING: Figure 3

Description

The present invention relates to a transport device that transports a sheet in a transport path provided with an ultrasonic sensor, and particularly relates to an improvement in a case where a type of a printable medium is determined using an ultrasonic sensor.

The ultrasonic sensor in the transport device is composed of a pair of a transmitting element and a receiving element that face each other across a transport path. When ultrasonic waves are emitted during sheet transportation in a transport path provided with an ultrasonic sensor, the detection signal output from the receiving element of the ultrasonic sensor is attenuated as the print medium passes through. That is, if the thickness of the print medium passing through the transport path is small, the attenuation of the ultrasonic waves received by the receiving element is small, and conversely, if the thickness of the print medium passing through the transport path is large, the ultrasonic waves are received by the receiving element. The attenuation of ultrasonic waves becomes large. The amount of attenuation of this received signal is larger when the envelope is passed than when the plain paper is passed. This is because the envelope has a structure in which two or more sheets are overlapped and the edges are bound, and the presence of an air layer between the sheets causes a large attenuation in the received signal. Based on the level of the attenuated ultrasonic waves appearing in the detection signal, the conventional transfer device determines whether or not the type of the printed medium that has passed through the transfer path is an envelope.

JP-A-2007-168928

By the way, the large attenuation of ultrasonic waves is not detected only when the envelope is passed through. It is also detected when two or more sheets are fed out from the storage tray in an overlapping manner and a state in which two or more sheets are overlapped (generally called double feeding) occurs. This is because an air layer is formed between the two sheets of plain paper that have been double-fed. If it is detected that the attenuation of the received signal caused by the double feed is due to the paper passing through the envelope, the processing required for the detection of the double feed (paper transport in the transport path as described in Patent Document 1 and paper transport in the transport path as described in Patent Document 1) and Stop printing) cannot be executed. When trying to convey two or more overlapping sheets, the following problems occur. When the first and second sheets that overlap each other pass through the transfer roller, the first sheet in contact with the transfer roller on the drive side is conveyed, but the second sheet in contact with the transfer roller on the driven side is made of a roller member. The conveying force may not be transmitted to the sheet, and the sheet may remain in the conveying path. When the transport path is jammed due to the remaining sheet, the sheet is bent or torn, which makes the sheet unusable and wastes the sheet. Such waste of the sheet due to the image forming apparatus erroneously determining the medium type has a problem that the user's understanding cannot be obtained at all and the impression of the product quality of the image forming apparatus is greatly impaired.

Alternatively, in order to eliminate the possibility of false positives, it is conceivable to apply a pre-input technique as described in Patent Document 1. The image forming apparatus disclosed in Patent Document 1 requires the user to pre-input whether or not the paper to be conveyed is an envelope, and if there is such pre-input, the detection of the air layer by the ultrasonic sensor is performed. Treat as due to double feeding. However, there is no guarantee that the user will perform such pre-input, and even if there is pre-input, it is not always correct. In the first place, the occurrence of double feeding is a problem of the transport member of the image forming apparatus and the transport device, and it is impossible to request prior input from the user. Therefore, the above problem of erroneous determination cannot be solved by the application of Patent Document 1. ..

An object of the present disclosure is to provide a transport device capable of preventing the occurrence of jam of paper due to an erroneous determination of the medium type of the printing medium.

The above-mentioned problem is a transport device for transporting a printable medium toward a printing unit along a transport path, and ultrasonic waves are transmitted to the printable medium during transport and attenuated by transmitting ultrasonic waves through the printable medium. When the ultrasonic sensor that detects ultrasonic waves and the level of ultrasonic waves detected by the ultrasonic sensor are below a predetermined threshold and the printing conditions for the printing medium are not suitable for printing an envelope, the subject is covered. This is solved by a transport device including a control means for stopping the transport of the print medium.

When the level of ultrasonic waves detected by the ultrasonic sensor is below a predetermined threshold value and the printing conditions for the printing medium are not suitable for printing envelopes, double feeding in a state where two or more sheets are overlapped. May have occurred.

When the medium type determining means for determining the type of the printed medium to be conveyed is provided and the level of ultrasonic waves detected by the ultrasonic sensor is equal to or higher than the predetermined threshold value, the medium type determining means has the printing conditions. , Regardless of whether or not it is suitable for printing the envelope, the type of the printing medium may be determined to be a sheet.

A plurality of storage trays are provided at the upstream end of the transport path, and the control means stops the transport of the printing medium as the first condition that the printing conditions are not suitable for printing envelopes but are suitable for printing sheets. If applicable,
The medium type determining means is
i) The printing conditions are the second printing conditions suitable for printing both sheets and envelopes.
ii) The job including the printing conditions selects a storage tray that has not yet supplied one sheet after the printing medium is stored.
iii) The type of the printed medium transported on the transport path is defined on the condition that the ultrasonic wave at a level below the predetermined threshold value is detected for the printed medium first supplied from the storage tray. It may be an envelope.

The printing unit executes printing by an electrophotographic method and fixes the image on the image carrier to the printing medium at the transfer position and the image transferred to the printing medium on the printing medium. Equipped with a fixing part to
When the medium type determining means uses an envelope as the type of the medium to be printed to be conveyed on the transport path, the transfer unit is instructed to perform transfer using a higher voltage than transfer to the sheet, and the transfer is performed on the sheet. Alternatively, the fixing unit may be instructed to perform thermal fixing with a high fixing temperature as the target temperature.

A predetermined time elapses from the supply sensor provided in each of the plurality of storage trays and detecting the supply start timing when the corresponding storage tray starts supplying the print medium, and the detected supply start timing. The storage tray containing the printing medium is provided with a sensor driving means for starting the driving of the ultrasonic sensor, and the transport distance from each storage tray to the ultrasonic sensor is different. It may be determined according to the length of the transport distance, which varies depending on which one is used.

In the transport path, a feeding roller for feeding out the printable medium stored in the storage tray, a supply roller for supplying the fed-out printable medium to the downstream side, and a timing for feeding the supplied printable medium to the transfer position. There is a timing roller to take the picture.
The ultrasonic sensor was installed at a position downstream of the supply roller and upstream of the timing roller in the transport direction of the printable medium in the transport path, and was detected by the ultrasonic sensor. If the ultrasonic level is below a predetermined threshold and the printing conditions are not suitable for printing an envelope, the control means may be applied to the printing medium before the printing medium reaches the timing roller. The transport may be stopped.

At a position downstream of the installation location of the ultrasonic sensor in the transport path, there is a guide member that guides the printing medium to a timing roller further downstream, and among the received signals emitted by the receiving element of the ultrasonic sensor, A partial waveform after the time when the tip of the printing medium collides with the guide member may be extracted, and the ultrasonic wave may be calculated from the extracted partial waveform.

The printing conditions that are not suitable for printing envelopes are an instruction for aggregate printing in which images of different pages are aggregated on one side of one sheet, or an image is formed on both sides of one sheet. It may include instructions for double-sided printing.

The printing conditions that are not suitable for printing the envelope may include instructions for post-processing to be performed on the printed sheet after printing on one sheet.

The post-processing instruction may be an instruction to bind the edge of the printed sheet.

The post-treatment instruction may be an instruction to perforate the edge of the printed sheet.

The post-processing instruction may be an instruction to Z-fold the printed sheet.

The post-treatment instruction may be an instruction to fold or saddle stitch the sheet.

The post-processing instruction may be an instruction for attaching a cover to create a sheet bundle by adding another sheet as a cover to the sheet to be printed.

The post-processing instruction may be cutting of a sheet on which an image related to a printing request is formed.

The image forming apparatus may include a conveying apparatus and a printing unit.

The transfer device according to the present disclosure is to be printed even when it is not possible to distinguish between a sheet and an envelope as the material to be printed, which is conveyed by the ultrasonic sensor, by the ultrasonic waves detected by the ultrasonic sensor. If the printing conditions for the medium are not suitable for printing envelopes, it is possible to stop the transport of two or more sheets that are overlapped and fed to the transport path by double feed. Therefore, in the transport device according to the present disclosure, jamming of the sheet due to erroneous determination of the medium type can be prevented, and damage due to bending or tearing of the sheet can be prevented, so that waste of the sheet can be avoided. be able to.

The appearance of the image forming apparatus 1000 which is a printer is shown. The internal configuration of the printing unit and the transport device is shown. The configuration of the control system of the image forming apparatus 1000 is shown. It is a block diagram which shows the internal structure of an ultrasonic sensor 117. FIG. 5A shows a transmission waveform by the transmitting element 115 of the ultrasonic sensor 117, and FIG. 5B shows the receiving element 116 outputting when there is no paper between the transmitting element 115 and the receiving element 116. The received waveform is shown. FIG. 5C shows a received waveform with a small amount of attenuation 116N, and FIG. 5D shows a received waveform with a large attenuation 116E. It is a flowchart which shows the processing procedure of the print condition conformity determination unit 106, and the paper processing determination unit 107. It is a flowchart which shows the detail of the conformity determination procedure of a print condition by a print condition conformity determination unit 106. 8 (a) to 8 (d) show the states of a plurality of sheets stored in the paper feed cassette. The details of the printing conditions in the job data A to D and the state of each tray are shown. This is an example of a timing chart showing the timing of driving the ultrasonic sensor 117 by the drive instruction unit 303. The situation where the tip of the conveyed paper collides with the guide plate 116G of the conveying path 120 is shown. 12 (a) and 12 (b) are views showing the configuration of the post-processing apparatus 1003 for binding. 13 (a) and 13 (b) show the configuration of the post-processing device 1003 that exhibits the punch function. It is a figure which shows the structure of the post-processing apparatus 1003 which executes Z folding. It is a figure which shows the structure of the post-processing apparatus 1003 which executes the saddle stitching / folding function. It is a figure which shows the structure of the post-processing apparatus 1003 which executes cutting. It is a figure which shows the structure of the post-processing apparatus 1003 which attaches a cover.

Hereinafter, embodiments of the apparatus according to the present disclosure will be described with reference to the drawings.

[1] Printer Configuration FIG. 1 shows the appearance of the image forming apparatus 1000 which is a printer. The image forming apparatus 1000 shown in FIG. 1 is a multifunction peripheral, and functions as a copier and a printer. When functioning as a copier, the touch panel display 1001 accepts the copy job settings, the scanner 1004 optically reads the original image, and the paper cassettes 1002a, b, c, and d feed the printed medium. An image is formed according to the above settings. When functioning as a printer, the print job settings are accepted from the menu of the terminal 1011, the data described in the printer description language is received by wired or wireless communication, and the image according to the settings accepted in the menu is sent to the paper cassette. It is formed on the printing medium fed out from 1002a, b, c, and d. The printable medium on which the image is formed is discharged to the tray 1003T via the post-processing device 1003. The printable medium on which the image is formed by the copy job and the printer job includes standard paper (for example, A3 to A7 size paper, B4 to B7 size paper, and postcard) accommodated in the paper feed cassettes 1002a, b, c, and d. , Envelopes, etc.) and irregular paper loaded on the manual feed tray 1002h.

In the following description, these various types of printable media will be collectively referred to as "paper". The post-processing device 1003 performs post-processing such as binding on the discharged paper in response to a request from the user.

[2] Configuration of Printing Unit and Transfer Device in Image Forming Device 1000 The image forming device 1000 is composed of a printing unit and a transport device. FIG. 2 shows the internal configuration of the printing unit and the transport device. The transport device includes a transport path 120, a transport member provided therein, an ultrasonic sensor 117 (including a transmitting element 115 and a receiving element 116), and a paper feed sensor 122S, 132S, 142S, 152S.

As the transport members, the paper feed roller 122 that feeds the paper fed by the pickup roller 121 from the first-stage paper feed cassette 1002a further downstream, and the paper fed by the paper feed roller 122 are further referred to as a toner image. The timing roller 123, which feeds the paper to the transfer position of the above, and the paper feed rollers 132, 142, which take over the paper fed by the pickup rollers 131, 141, 151 from the second and subsequent paper feed cassettes 1002b, c, d and feed it to the transport path. There are 152 and vertical transport rollers 133, 143, and 153 that take over the paper fed by the paper feed rollers 132, 142, and 152 and feed the paper to the timing roller 123.

The paper feed sensors 122S, 132S, 142S, and 152S detect the timing at which the paper is fed out from each of the paper feed cassettes 1002a, b, c, and d.

Next, the printing unit will be described. The printing unit is an electrophotographic method and includes a photoconductor 112D, an exposure device 110, a developing device 111, a transfer unit 112, and a fixing unit 113.

The exposure device 110 forms an electrostatic latent image on the photoconductor 112D based on the image data, and the developing device 111 develops the electrostatic latent image of the photoconductor 112D with toner to form a toner image. The transfer unit 112 primary transfers the toner image formed on the photoconductor 112D to the intermediate transfer belt 112N. The toner image primaryly transferred to the intermediate transfer belt 112N is transferred to the paper passing through the secondary transfer position 112P.

The fixing unit 113 heat-fixes the toner image transferred to the paper. The paper fixed by the fixing unit 113 is discharged from the discharge port 119 by the rotation of the discharge roller 118 and sent to the aftertreatment device 1003.

The transport device also has a transport path 160 for double-sided printing. When performing double-sided printing, the discharge roller 118 is rotated clockwise ro1 to discharge a part of the paper from the discharge port to the outside of the device, and the discharge roller is rotated counterclockwise to switch back. The switched-backed paper is fed to the timing roller 123 through the double-sided transfer rollers 161 and 162, 163, 164, and is fed to the secondary transfer position 112P through the timing roller 123.

[3] Control system of the image forming apparatus 1000 FIG. 3 shows the configuration of the control system of the image forming apparatus 1000. As shown in FIG. 3, the image forming apparatus 1000 includes a panel control unit 101, a queue memory 102, a job data execution unit 103, a mechanical controller 104, a tray management unit 105, a print condition conformity determination unit 106, and a paper processing determination unit 107. , Includes mechanical controller 108. Of these, the panel control unit 101, the queue memory 102, the job data execution unit 103, and the mechanical controller 104 are the control systems of the printing unit, and the tray management unit 105, the printing condition conformity determination unit 106, the paper processing determination unit 107, The mechanical controller 108 is a control system for the transport device.

(3-1) Panel control unit 101
The panel control unit 101 receives settings of items such as the number of copies required for job execution, background adjustment, density adjustment, page aggregation, and finishing through the touch panel display 1001 shown in FIG. 1, and orders the job execution with the received setting contents. Job data is generated and stored in the queue memory 102. The job data includes image data read by the scanner 1004, and is data for ordering image formation of the image data according to the syntax rules of the printer description language, and the job data includes designation of the number of tray stages and printing conditions. The number of tray stages takes a value from 1 to 4, and indicates which of the paper cassettes 1002a, b, c, and d is selected as the paper feed destination. Depending on the number of trays, the paper cassette 1002a is treated as "tray 1", the paper cassette 1002b is treated as "tray 2", the paper cassette 1002c is treated as "tray 3", and the paper cassette 1002d is treated as "tray 4". The printing conditions include the number of copies of paper to be printed, the background adjustment, the density adjustment designation, the page aggregation, and the finish designation.

(3-2) Queue memory 102
The queue memory 102 stores a plurality of job data indicating jobs to be executed according to the execution order. The job data stored in the queue memory 102 includes job data created by the panel control unit 101, as well as the application and device driver of the terminal 1011 shown in FIG. 1, and is created by the communication control unit 101T through a wireless or wired network. Has received job data. The job data created by the terminal 1011 is the document data created by the application of the terminal 1011 and the data that orders the image formation of the image data stored in the storage of the terminal 1011. In addition to specifying page aggregation, it also includes specifying that the character code included in the document data is expanded into print, and specifying the print range to be printed.

(3-3) Job data execution unit 103
The job data execution unit 103 fetches the job data stored in the queue memory 102 one by one, and according to the syntax rules of the printer description language, displays each page of the fetched job data as image data including characters, photographs, and figures. And write to the image memory 103M. Then, the image data written in the image memory 103M is converted into image data (exposure pattern) for print output.

(3-4) Mechanical controller 104
The mechanical controller (hereinafter referred to as a mechanical controller) 104 controls an exposure device 110, a developing device 111, a transfer unit 112, and a fixing unit 113 to perform exposure scanning and exposure scanning based on an exposure pattern obtained by converting image data. It consists of the development of the obtained electrostatic latent image and the transfer of the toner image obtained by the development (primary transfer from the photoconductor 112D shown in FIG. 2 to the intermediate transfer belt 112N and secondary transfer from the intermediate transfer belt 112N to the paper). ), Fixing the paper on which the toner image is transferred is sequentially executed. In the secondary transfer by the transfer unit 112 and the fixing by the fixing unit 113, the transfer voltage of the secondary transfer by the transfer unit 112 and the fixing temperature of the fixing unit are changed according to the determination result of the paper type by the paper processing determination unit 107. Specifically, if the paper type to be conveyed is an envelope, the transfer voltage of the secondary transfer by the transfer unit 112 and the fixing temperature of the fixing unit 113 are set to high values, respectively.

(3-5) Tray management unit 105
The tray management unit 105 manages the state of each tray and also manages the size of the paper stored in each tray by using the tray state table 105T. The states shown in the tray state table 105T include an eject state in which the paper cassette is pulled out, an empty state in which an empty paper cassette is loaded, and a set state in which the paper cassette containing paper is loaded (FIG. FIG. In one example of 3, trays 1 to 4 are set). For the paper cassettes in the set state (tray 1 to 3 in FIG. 3), the distinction between plain paper and envelopes is clearly indicated together with the paper size. It is stated that the paper cassette (tray 4 in FIG. 3) whose paper type is undetermined is "undecided". This paper type is described in conjunction with the status of the paper cassette. That is, once the paper cassette is pulled out and then set, the paper type is set to "undecided". This is because it is presumed that the paper was replaced when the paper cassette was pulled out once and then put into the set state.

(3-6) Printing condition conformity determination unit 106
The print condition conformity determination unit 106 refers to the print conditions of the first-ranked job data stored in the queue memory 102, and the print conditions conform to printing of both envelopes and plain paper. It is determined whether it is the second condition or the first condition that is suitable for printing on plain paper and not suitable for printing on envelopes. To determine whether or not the product is compliant, check whether the print conditions include an instruction for aggregated output, whether an instruction for double-sided printing is included, and whether a post-processing instruction is added to the print conditions. It is done by doing. When these instructions are included or added, it is determined that the printing condition of the job data, which is the first rank in the queue memory 102, is suitable only for printing on plain paper. On the other hand, when none of these instructions is included, it is determined that the printing condition of the job data, which is the first rank in the queue memory 102, is suitable for printing on both the envelope and the plain paper.

(3-7) Paper processing determination unit 107
When the peak value shown in the reception signal of the reception element 116 of FIG. 2 is below a predetermined threshold value and the ultrasonic sensor 117 detects the presence of the air layer, the paper processing determination unit 107 determines the print condition conformity determination unit 106. The handling of the detection result is determined according to the result of the conformity determination by. Specifically, when it is determined that the printing conditions of the earliest job data in the queue memory 102 are suitable only for printing on plain paper, the detection of the air layer by the ultrasonic sensor 117 is the double feeding of the paper. Printing by the printing department and paper transport in the transport path are stopped. As shown in FIG. 2, the ultrasonic sensor 117 is installed on the downstream side in the paper transport direction with respect to the paper feed roller 122 and on the upstream side in the paper transport direction with respect to the timing roller 123, and is ultrasonic. When the sensor 117 detects, the paper is fed out from the paper feed cassettes 1002a, b, c, and d, the exposure of the photoconductor drum 112D by the exposure device 110, and the development by the developer 111 have already been completed. There is. When the detection of the air layer by the ultrasonic sensor 117 is treated as the double feeding of the paper, the subsequent secondary transfer by the transfer unit 112 and the fixing by the fixing unit 113 are not performed, and the paper transfer in the transport path is ultrasonic. It will stop near the sensor 117.

When it is determined that the printing conditions of the earliest job data in the queue memory 102 are suitable for printing on both envelopes and plain paper, ultrasonic waves are referred to with reference to the state of each tray shown in the tray state table 105T. Determines whether to treat the detection of the air layer by the sensor 117 as an envelope. The determination of whether to treat the detection of the air layer as an envelope shall be described in detail later with a specific example of paper loading in the paper cassette.

(3-8) Mechanical controller 108
The mechanical controller (hereinafter referred to as a mechanical controller) 108 feeds out the paper from the paper feed cassettes 1002a, b, c, and d by controlling the transport member shown in FIG. 2, and transfers the paper to the intermediate transfer belt 112N and the secondary transfer. It is provided at the secondary transfer position 112P between the roller 112R (see FIG. 3). In paper transport, the drive of the transport member shown in FIG. 2 is stopped in accordance with the decision by the paper processing determination unit 107 to stop the paper transport.

(3-9) Drive instruction circuit 109
The drive instruction circuit 109 switches the timing for turning on the ultrasonic sensor 117 with reference to the switching time table 109T. The switching time table 204T describes the switching times (D1 to D4) corresponding to each of the paper cassettes 1002a, b, c, and d. These switching times are the distances on the transport path from the positions of the paper feed sensors 122S, 132S, 142S, 152S provided in each of the paper cassettes 1002a, b, c, and d to the installation positions of the ultrasonic sensors 117. , The value divided by the paper transport speed. The relationship between the switching times is D1 <D2 <D3 <D4, and the difference in the transport path length from each of the paper cassettes 1002a, b, c, and d to the installation position of the ultrasonic sensor is indicated. If any one of the paper cassettes 1002a, b, c, and d is selected as the paper feed port based on the job data, the switching time corresponding to the selected paper feed port is read from the switching time table 109T. Then, if the paper feed sensor corresponding to the paper feed port detects the passage of the paper, it waits for the read switching time to elapse, and when it elapses, it starts driving the ultrasonic sensor 117 and emits ultrasonic waves. Make a call. Since the ultrasonic sensor 117 is turned on after waiting for the elapse of the switching time according to the selection of the paper cassette, the paper tip is super even when the paper is fed from each of the paper cassettes 1002a, b, c, and d. Ultrasonic waves can be transmitted at the timing of passing through the installation location of the sound wave sensor 117.

(3-9-1) Sampling indicator 109I
The sampling indicator 109I waits for a predetermined wait time to elapse after the paper feed sensor of the tray detected by the job data detects the paper, performs sampling, and selects the plain paper and the attenuated portion due to the passage of the envelope. Command the ultrasonic sensor 117 to extract. The reason for waiting for the elapse of the wait time in this way is to exclude the impact noise generated by the contact between the guide plate 116G shown in FIG. 2 and the paper. That is, the paper transported in the transport path passes through the installation position of the ultrasonic sensor 117, and then the tip of the paper collides with the guide plate 116G shown in FIG. If the collision sound due to such a collision appears in the signal waveform, the determination accuracy is deteriorated. Therefore, the time required for the paper tip to reach the guide member after the paper is detected by the paper feed sensors 122S, 132S, 142S, and 152S is measured in advance, and a slight offset is added to the required time. The time is defined as the wait time (Sd in FIG. 10). Then, the receiving element 116 of the ultrasonic sensor 117 starts outputting the received signal, and the ultrasonic sensor 117 is instructed to extract the attenuated portion from the time when the predetermined wait time has elapsed.

[4] Internal Configuration of Ultrasonic Sensor 117 FIG. 4 is a block diagram showing an internal configuration of the ultrasonic sensor 117. As shown in this figure, in addition to the transmitting element 115 and the receiving element 116 shown in FIG. 2, the ultrasonic sensor 117 includes a clock circuit 201, a burst wave generation circuit 202, a drive circuit 203, an amplifier circuit 204, and an absolute value circuit 205. , The amplifier circuit 206, the AD converter 207, and the detection waveform memory 208.

The clock circuit 201 generates a clock signal having a frequency unique to the transmitting element.

The burst wave generation circuit 202 converts the clock signal generated by the clock circuit 201 into a burst wave.

The drive circuit 203 applies a voltage according to the peak value of the burst wave generated by the burst wave generation circuit 202 to the transmitting element 115 to cause the transmitting element 115 to transmit ultrasonic waves. In this way, the ultrasonic waves emitted by the transmitting element 115 pass through the paper passing through the transport path and are received by the receiving element 116. The receiving element 116 that has received the ultrasonic wave outputs an AC signal in response to the reception of the ultrasonic wave. The transmitting element 115 and the receiving element 116 shall transmit and receive ultrasonic waves in the frequency band of 300 KHz.

The amplifier circuit 204 amplifies the AC received signal output from the receiving element 116 to a voltage level that can be processed by a standard logic circuit.

The absolute value circuit 205 converts the received signal output from the receiving element 116 into an absolute value by leaving a positive half-wave portion of the AC received signal amplified by the amplifier circuit 204. The voltage of the received signal output by the receiving element 116 indicates the peak value of the ultrasonic wave passing through the paper. Therefore, when the paper is an envelope and an air layer is present, the peak value of the ultrasonic waves passing through the paper is low, so that the voltage of the received signal output by the receiving element 116 is low.

The integrator circuit 206 performs an integral process on the detection signal that has been converted to an absolute value by the absolute value circuit 205 to form a form suitable for quantization by the AD converter 207.

The AD converter 207 samples the received signal of the ultrasonic sensor 117 output by the receiving element 116 at a predetermined sampling frequency, converts the waveform of the received signal into a discrete value (sampling data), and generates sampling data. Is written to the detection waveform memory 208. With reference to such sampling data, the detection result of whether or not the received signal is attenuated is output.

[5] Operation Description The operation of the image forming apparatus 1000 configured as described above will be described.

(5-1) Transmission / reception of signal by ultrasonic sensor 117 Each time paper is conveyed in the transport path 120, the transmitting element 115 and the receiving element 116 of the ultrasonic sensor 117 transmit as shown in FIGS. 5 (a) to 5 (d). Sends and receives signals and received signals.

FIG. 5A shows a transmission waveform by the transmitting element 115 of the ultrasonic sensor 117, and FIG. 5B shows the receiving element 116 when there is no paper between the transmitting element 115 and the receiving element 116. Indicates the received waveform output by. In each of FIGS. 5A to 5D, the horizontal axis represents the time axis and the vertical axis represents the voltage. Since the transmitting element 115 and the receiving element 116 face each other with the transport path in between, the waveform of the ultrasonic wave emitted by the transmitting element 115 appears almost as it is in the receiving waveform of the receiving element 116. In the present embodiment, the threshold value Vh is set to about half the peak value of the received signal output by the receiving element 116 when the paper is not passed through as shown in FIG. 5 (b).

FIG. 5C shows the peak value of the received signal detected by the ultrasonic sensor 117 while the plain paper is being conveyed. As shown in FIG. 5C, when the attenuation 116N of the reception signal 116W of the reception element 116 is small and the peak value 116M of the reception signal exceeds the threshold value Vh, the attenuation shown in the reception signal of the reception element 116 is shown. Outputs the detection result that the attenuation is during the transfer of plain paper. As shown in FIG. 5D, when the attenuation 116E of the received signal 116W of the receiving element 116 becomes large and the peak value 116D shown in the received signal of the receiving element 116 is lower than the threshold value Vh, the peak value is , Outputs the detection result of the envelope transportation. However, when two or more sheets of plain paper overlapping each other due to double feeding pass between the transmitting element 115 and the receiving element 116, the ultrasonic sensor 117 causes the air between the overlapping sheets to pass. The layer detects the peak value that is greatly attenuated.

In order to distinguish between the attenuation of the received waveform due to double feeding and the attenuation of the received waveform due to the envelope, the print condition conformity determination unit 106 and the paper processing determination unit 107 execute the procedure shown in the flowchart of FIG. FIG. 6 is a flowchart showing a processing procedure of the print condition conformity determination unit 106 and the paper processing determination unit 107.

(5-2) Delivery type determination procedure It is determined whether or not the job data is accumulated in the queue (step S101), and if it is accumulated (Yes in step S101), the earliest job data is taken out (step S101). S102). In the extracted printing conditions, it is determined whether or not the printing conditions set by the user are compatible with the envelope transportation (step S103).

The procedure of step S103 described above is expanded to the subroutine of FIG. FIG. 7 is a flowchart showing details of the processing procedure by the print condition conformity determination unit 106.

This flowchart is sequentially executed in steps S201 to S203. Step S201 is a determination as to whether or not a post-processing instruction is added to the print condition of the earliest job data in the queue memory 102, and step S202 is a determination of whether or not the print condition of the earliest job data is double-sided. Judgment as to whether or not to include a print instruction, step S203 is a determination as to whether or not the print condition of the earliest job data includes an aggregation instruction. If any of steps S201 to S203 is Yes, it is determined that the printing condition of the earliest job data does not match the envelope printing (step S204), and the process returns to the flowchart of FIG.

If any of steps S201 to S203 is No, the printing condition of the earliest job data is determined to be compatible with envelope printing (step S205), and the process returns to the flowchart of FIG. If they do not match (No in step S103 of FIG. 6), processing for envelopes is prohibited (step S104), and the peak value of ultrasonic waves after passing through the paper detected by the ultrasonic sensor 117 has a threshold value of Vh. It is lower, and it is determined whether or not the detection result by the ultrasonic sensor 117 indicates the presence of the air layer (step S105). When the presence of the air layer is not shown (No in step S105), it is determined that the type of the print medium is plain paper (step S106), and the process returns to step S101.

When the detection result by the ultrasonic sensor 117 indicates the presence of an air layer (Yes in step S105), it is determined that double feeding has occurred (step S107), and the paper is conveyed along the conveying path and printed. Printing by the unit is stopped (step S108).

When it is determined that the printing conditions set by the user are compatible with the envelope printing in the extracted printing conditions (Yes in step S103), the peak value of the ultrasonic waves after passing through the paper detected by the ultrasonic sensor 117 is determined. It is determined whether or not it is below the threshold value Vh and indicates the presence of an air layer (step S111). When the crest value exceeds the threshold value Vh and does not indicate the presence of the air layer (No in step S111), the process proceeds to step S106, and a determination result is made that the type of the print medium is plain paper.

When the peak value of the ultrasonic wave after passing through the paper detected by the ultrasonic sensor 117 is below the threshold value Vh and indicates the presence of an air layer (Yes in step S111), in step S112, the paper feeding by the job data is performed. Determine if this is the first paper feed after paper replacement.

In step S112, double feeding is unlikely to occur in the feeding of the first page immediately after the paper replacement, and double feeding is likely to occur in the paper S2 overlapping the paper S1 and the paper S3 overlapping the paper S2. Based on the past empirical rule, the handling of the detection result by the ultrasonic sensor 117 is determined.

This empirical rule will be described below. Immediately after the paper is replaced, when the topmost paper in the paper bundle stored in the paper cassette is to be conveyed, as shown in FIG. 8A, the paper S1 and the papers S2 and S3 below the paper S1 are used. Then, the tips in the transport direction (paper tips) are aligned. When the pickup roller 121 starts rotating in this state, as shown in FIG. 8B, the paper S1 heads toward the paper feed roller 122, but the paper S2 is connected to the paper S1 and the paper S2 lags behind the paper S1. Head to. However, in most cases, as shown in FIG. 8C, the next-order paper S2 reaches the nip 122N after the paper tip of the paper S1 passes through the nip 122N. The transport of the paper S2 is blocked by receiving a frictional force from the handling roller 122r, and does not pass through the nip 122N. In a situation where the paper tips of the papers S1, S2, and S3 are aligned, the regularity that the paper tip of the paper S1 passes through the nip 122N and then the next-order paper S2 reaches the nip 122N is maintained. Immediately after the paper cassette is replaced, double feeding of paper cannot occur, and when the ultrasonic sensor 117 detects a large attenuation of ultrasonic waves, it is treated as due to the paper feeding of the envelope.

On the other hand, the situation in which double feeding is likely to occur is as shown in FIG. 8 (d). This is a situation in which, after the paper S1 is fed, the paper S2 and S3 overlap each other, the tip of the paper reaches near the nip 122N, and the paper S1 is stopped. The papers S2 and S3 are papers on which double feeding is likely to occur, and are fed out to the nip 122N as the paper S1 is fed. When the rotation of the pickup roller 121 is started in this state, the paper S2 and the paper S3 try to pass through the nip 122N almost at the same time. Since the paper S3 receives a force (handling force) in the direction opposite to the transport direction by the handling roller 122r, the paper S3 is usually prevented from being conveyed. However, under the situation of FIG. 8D, the rotation of the pickup roller 121 continues for a long time until the rear end of the paper S2 passes through the pickup roller 121, so that the handling force of the handling roller 122r is lost in the middle of the rotation. The paper S2 and the paper S3 may be pulled out from the nip 122N of the paper feed roller 122 and the handling roller 122r while being overlapped with each other. This causes double feeding. This also applies when feeding paper below paper S3.

It is rare that the paper stored in the paper cassettes 1002a, b, c, and d is in the situation shown in FIG. 8D. Immediately after the paper in the paper cassette is replaced, the bundle of paper contained in the paper cassette is in the state shown in FIG. 8A, and it can be considered that double feeding cannot occur. Under such a prospect, when the ultrasonic sensor 117 detects the presence of the air layer immediately after the paper cassette is replaced, the paper contained in the paper cassette is assumed to be an envelope.

If the paper is fed from the selected tray for the second and subsequent sheets, step S112 becomes No, and the process proceeds to step S113. Step S113 determines whether the paper type of the tray selected by the job data is an envelope. The paper stored in the paper cassettes 1002a, b, c, and d is unified to either plain paper or an envelope. If it is determined that the paper type is an envelope in the first paper feeding after the paper exchange, it should be determined that the paper type is an envelope in the subsequent paper feeding. After the paper exchange, if the paper type of the tray selected by the job data is an envelope, step S113 becomes Yes, and it is determined that the paper type is an envelope (step S114). At this time, the paper processing determination unit 107 instructs the mechanical controller 104 to set the secondary transfer voltage by the transfer unit 112 and the fixing temperature by the fixing unit 113 according to Table 1 below.

When it is determined in step S106 of FIG. 6 that the type of paper is plain paper, as shown in Table 1, the secondary transfer voltage by the transfer unit 112 is set to Vn, and the fixing temperature by the fixing unit 113 is set to 145 ° C. .. When it is determined in step S114 of FIG. 6 that the type of paper is an envelope, the secondary transfer voltage by the transfer unit 112 is set to Vn + 300V, and the fixing temperature by the fixing unit 113 is set to 160 ° C.

If both step S112 and step S113 are No, the process proceeds to step S107, and the air layer detection by the ultrasonic sensor 117 is treated as double feeding of plain paper (step S107), and is along the transport path. Paper transport and printing by the printing unit are stopped (step S108).

(5-3) Specific Examples of Paper Type Judgment and Double Feed Judgment Paper type judgment when four job data (job data A, B, C, D) stored in the queue memory 102 of FIG. 3 are targeted. , The double feed determination will be described. FIG. 9 shows the details of the printing conditions in the job data A to D. In this figure, the details of the printing conditions of job data A to D are shown in the left row, the detection result of the ultrasonic sensor 117 is shown in the middle row, and the handling of paper is shown in the right row. The tray status table 105T is shown at the bottom.

Since the job data A includes a paper binding instruction, when the ultrasonic sensor detects the presence of an air layer, step S103 becomes No and step S105 becomes Yes, and the detection result by the ultrasonic sensor is used as the judgment result of the paper type. Instead, processing for the envelope is prohibited (step S104), and the attenuation of the received signal output by the ultrasonic sensor 117 is treated as double feeding (step S107). Since the processing for the envelope is prohibited (step S104), the secondary transfer by a high voltage and the fixing at a high temperature are not executed. Instead, as a measure against the double feed, the paper transport along the transport path and the printing by the printing unit are stopped (step S108).

Since the job data B includes the aggregation instruction and the job data C includes the instruction on both sides, when the ultrasonic sensor detects the presence of the air layer, step S103 becomes No, step S105 becomes Yes, and the ultrasonic sensor determines. The detection result is not used as the determination result of the paper type, the processing for the envelope is prohibited (step S104), and the attenuation of the received signal output by the ultrasonic sensor 117 is treated as double feeding (step S107). Since the processing for the envelope is prohibited (step S104), the secondary transfer by a high voltage and the fixing at a high temperature are not executed. Instead, as a measure against the double feed, the paper transport along the transport path and the printing by the printing unit are stopped (step S108).

Of the paper cassettes 1002a, b, c, and d, it is assumed that the paper of the paper cassette 1002d is replaced with an envelope from plain paper. As the job data D, it is assumed that the paper cassette 1002d after the paper exchange is selected.

Since the job data D does not include a paper binding instruction or an aggregation instruction and does not have a double-sided printing instruction, step S103 is Yes. Since the envelope is housed in the paper cassette 1002b, the presence of the air layer is detected by the ultrasonic sensor from the time when the first sheet is fed out. Therefore, step S111 becomes Yes and step S112 becomes Yes, and it is determined that the paper supplied from the paper cassette 1002c is an envelope (step S114).

(5-4) Transmission / reception control when job data A to D are executed FIG. 10 is an example of a timing chart showing a drive timing instruction of the ultrasonic sensor 117 by the drive instruction unit 303.

The horizontal axis of this figure is the time axis, the first stage is the paper detection timing by the paper feed sensor of the first tray 1, the second, third, and fourth stages are the second, third, and fourth stages. The paper detection timing by the paper feed sensors of the trays 2, 3 and 4 is shown. The fifth stage shows the drive timing of the ultrasonic sensor 117 by the drive indicator 303. The time points t1 to t4 indicate the time points when the paper is detected by the paper feed sensors in the first to fourth stages.

D1 to D4 are switching times used by the drive instruction unit 303 to drive the ultrasonic sensor 117, and the first-stage to fourth-stage paper feed sensors detect the paper fed out from each tray. The time from when the ultrasonic sensor is turned on is shown. As described above, the switching times D1 to D4 are determined based on the value obtained by dividing the distance from the installation position of the paper feed sensor in each stage to the installation position of the ultrasonic sensor by the paper transport speed. If the ultrasonic sensor 117 is driven from the detection time (t1 to t4 in FIG. 10) when the paper feed sensor of each stage detects the presence of paper to the time 121T when the corresponding switching time elapses, the paper feed cassette 1002a , B, c, or d, the ultrasonic sensor 117 is driven ON at the same time point (121T in the figure). The reception waveform 116W indicates a reception waveform received by the receiving element. The peak 116P in the received waveform 116W indicates an impact sound generated when the tip of the conveyed paper collides with the guide plate 116G of the conveying path 120 in FIG. The sampling data string 116S in FIG. 10 shows a sampling data string obtained by quantizing the received waveform 116W in the sixth stage. The period Sd in FIG. 10 indicates the delay time from the beginning of the received waveform 116W until the sampling data string 116S appears. Since the delay time Sd is set to indicate the time after the occurrence of the peak 116P, the portion of the received waveform 116W after the peak 116P is converted into the sampling data string 116S. Since the attenuated portion is extracted from the portion of the received waveform 116W after the peak 116P, the influence of the impact sound generated when the paper tip collides with the guide plate 116G can be removed.

(5-5) Execution of the binding function by the post-processing device 1003 The post-processing device 1003 is configured as shown in FIGS. 12A and 12B, and executes the binding function according to the binding instruction in the printing conditions of the job data. .. FIG. 12A is a diagram showing a configuration of a post-processing device 1003 for binding.

In the transport roller pairs 411, 421, and 413 in FIG. 12A, the paper S output one by one from the discharge roller pair 418 is conveyed on the transport path 440 in the aftertreatment device 1003, and the discharge roller pair 414 is conveyed. Send to.

When binding, the discharge roller pair 414 switches back the paper S and conveys the paper S toward the tray 420 of the matching portion 442.

Each time a sheet of paper S is conveyed onto the tray 420, the pair of compatible plates 421 and 422 shown in the plan view of FIG. 12B are arranged in a direction approaching the center line CL from the home position indicated by the broken line. After moving to a suitable position according to the size of the paper S, the operation of returning to the home position is repeated.

The binding unit 426 is fixedly arranged in an inclined posture in which it is inclined at an angle of 45 ° with respect to the transport direction, and is formed by a pair of crimping teeth (only the upper crimping tooth 471 is shown by a broken line in the figure). The paper portion of the corner Su of the paper bundle Sb is sandwiched and crimped with a strong force. As a result, needleless diagonal binding is performed.

When the binding process for the paper bundle Sb is completed, as shown in FIG. 12A, the plate-shaped transport member 425 is moved in the direction of arrow A in a state of being in contact with the tip Se of the paper bundle Sb. By moving the transport member 425 in the direction of arrow A, the paper bundle Sb on the tray 420 is transported toward the discharge roller pair 414. The discharge roller pair 414 discharges the paper bundle Sb conveyed to the discharge roller pair 414 by the transport member 425 to the outside of the machine and accommodates the paper bundle Sb on the paper discharge tray 404a.

[6] Summary As described above, according to the present embodiment, the print condition conformity determination unit 106 determines the compatibility between the print condition in the job data determined by the user and the printing of the envelope, and the print condition of the job data. If is not compatible, the setting of the secondary transfer voltage by the transfer unit 112 for the envelope and the setting of the fixing temperature by the fixing unit 113 are prohibited. Therefore, these settings cannot be mistakenly executed for plain paper. No. In addition, since it is comprehensively determined whether the paper feed from the tray selected in the job data is the first paper feed after the paper change in the selected tray, a plausible guess as to whether the print medium is an envelope is made. be able to. Based on such a guess, it is decided whether or not to prohibit the control as an envelope, so that the processing required for passing the envelope, such as fixing at a high temperature, can be performed in a limited manner.

[7] Modified Examples Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and the following modified examples can be considered.

(1) The post-processing apparatus 1003 may be configured as shown in FIGS. 13 (a) and 13 (b), and the punch function may be executed according to the instructions of the punch function in the post-processing added to the print conditions of the job data. As shown in FIG. 13A, the punch unit 520 is installed on the transport path 512 and between the transport rollers 541 and 542.

As shown in FIG. 13B, the punch unit 520 includes two punching rods 522 and drills holes h in the rear end edge of the paper S conveyed in the direction of arrow A (first direction). The perforated paper is discharged to the outside of the device by the transport path 515 and the discharge roller 516, or is collected in the collection box 535 through the transport path 517.

(2) The post-processing device 1003 may be configured as shown in FIG. 14, and Z-folding may be executed according to the Z-folding instruction in the printing conditions of the job data. FIG. 14 is a diagram showing a configuration of a post-processing device 1003 that executes Z-folding.

When Z-folding is selected in the post-processing added to the printing conditions, the transfer rollers 622 and 623, the folding rollers 626, the transfer rollers 627, the folding rollers 628, and the transfer rollers 629 in FIG. 14 are driven. The paper S on the transport path 620 is drawn into the transport path 630 branched in the middle of the transport path 620 and Z-folded. The Z-folded paper S is conveyed from the transfer path 630 via the transfer path 631 branched in the middle of the transfer path 630, and then returned to the transfer path 620.

When staples are selected in the printing conditions, the transfer destination of the paper S on the transfer path 620 is switched to the transfer path 632 which is a branch path by the switching claw 635 and sent to the stapler unit 621b. The paper S sent to the stapler unit 621b includes a paper S that has not been folded in three and a paper S that has been folded in three.

When a plurality of sheets of paper S are loaded on the staple tray 634, the staple unit 633 staples the bundle of paper with staples. The bundle of paper after staple binding is conveyed on the staple tray 634 by a conveying member (not shown) and accommodated in the output tray 637.

(3) Even if the post-processing device 1003 is configured as shown in FIG. 15 and the saddle-stitching / center-folding function is executed according to the instructions of the saddle-stitching / center-folding function in the post-processing added to the print conditions of the job data. good. FIG. 15 is a diagram showing a configuration of a post-processing device 1003 that executes a saddle stitching / folding function. The paper P introduced into the transport path R1 of the aftertreatment device 1003 enters the stack means 723 inclined at a predetermined angle via the saddle carry-in roller 722. When a plurality of sheets are stacked in the stacking means 723, the bundle of paper housed and held in the stacking means 723 is saddle-stitched by the saddle-stitching stapler 731. In the case of only the saddle stitching process, the saddle stitching process is not performed. After that, the central portion of the bundle of paper P is bent by the operation of the folding knife 736 and pushed into the nip portion of the pair of folding rollers 735, and is sandwiched between the nip portions by the rotation of the folding roller 735. After that, the bundle of paper P in which the creases are formed passes through the folding roller 735 and is discharged onto the tray 724 from the discharge port 760 of the aftertreatment device.

(4) The post-processing apparatus 1003 may be configured as shown in FIGS. 16A and 16B, and cutting may be executed according to the cutting instruction in the post-processing added to the printing conditions of the job data. 16 (a) and 16 (b) are views showing the configuration of the post-processing device 1003 that executes cutting.

The cutting unit 801 cuts the paper P in the CD direction (CD cutting), which is a direction intersecting the conveying direction of the paper P, and the paper P cut by the CD cutting unit 802 of the paper P. It is provided with an FD cutting unit 803 that cuts (FD cutting) in the transport direction (FD direction). The CD cutting section 802 and the FD cutting section 803 are a pair of disc cutters installed so as to sandwich the paper P.

When the paper P is conveyed to the cutting position H1, the paper P is stopped at the cutting position H1, the CD cutting portion 802 is pressed so as to sandwich the paper P, and the paper P reciprocates in the CD direction as shown in FIG. 16 (b). By letting the paper P be cut into CDs. When the CD cutting is completed, the FD cutting unit 803 at the cutting position H2 is moved to a predetermined position in the CD direction. Then, the FD cutting is completed by transporting the paper P to the transport unit 804 while pressing the FD cutting unit 803 against the paper P so as to sandwich the paper P.

(5) The post-processing device 1003 may be configured as shown in FIG. 17, and the cover may be attached according to the instructions for the cover in the job data printing conditions. FIG. 17 is a diagram showing a configuration of a post-processing device 1003 for attaching a cover.

FIG. 17 shows the internal configuration of the post-processing apparatus 1003, which attaches a cover as post-processing. The paper sent from the image forming apparatus 1000 is sent to the tray 801 to align the inner paper of the bookbinding bundle (the bundle whose cover is not attached to the book), and the alignment operation is performed for each paper.

When the final paper of the bookbinding bundle is aligned on the tray 801, the cover is sent from the main body. When the cover page is sent, the branch claw 815 is switched to transport the paper to the transport path 816. Then, when the spine of the bookbinding comes to the position of the roller 813, the cover is stopped. At this time, the size of the cover is twice as large as that of the inner paper.

After that, the paper bundles arranged in the tray 801 by the rollers 810a are conveyed for gluing. When the tip of the paper (the part that becomes the spine of the bookbinding) comes out from the roller 810b, the bundle is stopped, and the glue tub 817 is moved under the bundle to perform gluing. After that, the glue tub 817 is retracted and a glued bundle is attached to the cover which has been conveyed in advance. After that, the back plate 812 is retracted and the roller 813 is driven, and the bound bundle is discharged to the bookbinding tray 814.

(6) The ultrasonic sensor 117 of the above embodiment has a configuration in which the transmitting element 115 and the receiving element 116 face each other with the transport path interposed therebetween, but the present invention is not limited to this. One piezoelectric element may serve as both a transmitting element 115 and a receiving element 116. The ultrasonic sensor 117 having such a configuration performs a function as a transmitting element 115 and a function as a receiving element 116 in a time division manner. In one time unit (slot) of the time division process, the ultrasonic sensor 117 emits ultrasonic waves toward the paper to be conveyed in the transport path. In the next slot, the transmitted ultrasonic wave receives the reflected wave due to being reflected by the partition wall or the like around the transport path. The peak value of the reflected wave received in this way has an amount of attenuation according to the thickness of the paper, and by referring to the amount of attenuation, whether or not the papers are overlapped and sent is usually determined by the paper. It is possible to determine whether or not the paper has a thickness. In this way, the ultrasonic sensor 117 can be made into a simpler configuration by performing the double feed determination based on the attenuation amount of the reflected wave. Further, the paper type was determined using the sampling data, but the present invention is not limited to this. The paper type may be determined by processing for analog signals.

Furthermore, by using the detection results of the optical sensors provided in the transport path and the paper size sensors provided in the paper cassettes 1002a, b, c, and d together, the type of paper to be transported can be specified in detail. May be good. Further, by referring to the detection signal output by the ultrasonic sensor 117, it may be determined whether or not the flap of the envelope has reached the installation position of the ultrasonic sensor 117. By specifying the arrival point of the flap in this way, the arrival point of the envelope end may be detected.

(7) In determining the medium type of the printing medium from the received signal output by the ultrasonic sensor 117, the voltage of the received signal indicating the peak value of the ultrasonic wave was compared with the threshold value, but the present invention is not limited to this. Others may be used as long as they indicate the amount of energy transmitted by ultrasonic waves. Specifically, the medium type of the printing medium may be determined by comparing the average of the peak values and the amount of heat transmitted by the ultrasonic waves per unit time with the threshold value. Further, in the above embodiment, the ultrasonic sensor 117 is driven after waiting for the paper to reach the installation location of the ultrasonic sensor 117, but the present invention is not limited to this. Ultrasonic waves may be transmitted from beginning to end during the activation of the image forming apparatus 1000.

(8) In determining whether post-processing is added to the print conditions, a PJL (Printer Job Language) output command (PJL SET OUTBIN command) or a finish command (PJL SET FINISH = STAPLE, etc.) that orders the execution of staples, etc. ) May be determined by referring to the presence or absence. Of course, it may be determined whether or not post-processing is added based on the grammatical rules of computer description languages other than PJL.

(9) In the above embodiment, the image forming apparatus 1000 provided with the conveying apparatus is used as the MFP, but the present invention is not limited to this. It may be provided in a production printing device. Further, it may be provided in a single-function copier or a single-function peripheral device (printer) of a personal computer. Further, the present invention is not limited to the electrophotographic image forming apparatus, and may be provided in the inkjet type image forming apparatus. Further, it may be provided in a label printing machine, a postcard printing machine, or a ticket issuing machine.

A monochrome image forming apparatus having an exposure device 110 and a developing device 111 as an image forming apparatus 1000 has been disclosed, but the present invention is not limited thereto. An exposure device 110 and a developer 111 may be provided for each of the Y, M, C, and K colors to form a color-type image forming apparatus.

The transport device and image forming device according to the present disclosure are suitable for use in workplaces where both plain paper and envelopes are frequently used, and are suitable for use in the industrial fields of OA equipment and information equipment, as well as retail, rental, and real estate. It may be used in various industrial fields such as industry, advertising, transportation, and publishing.

101 Panel control unit 103 Job data execution unit 104 Mechanical controller 105 Tray management unit 106 Printing condition conforming unit 107 Paper processing determination unit 108 Mechanical controller 109 Drive instruction circuit 109I Sampling instruction unit 109T Switching time table 110 Exposure device 111 Developer 112 Transfer unit 113 Fixing part 115 Transmitting element 116 Receiving element 117 Ultrasonic sensor 1000 Image forming device 1001 Touch panel display 1002a to d Paper feed cassette 1003 Post-processing device 1004 Scanner 1011 Terminal

Claims (17)

A transport device that transports a medium to be printed toward a printing unit along a transport path.
An ultrasonic sensor that emits ultrasonic waves to the printed medium being conveyed and detects the attenuated ultrasonic waves via the printed medium, and an ultrasonic sensor.
When the level of ultrasonic waves detected by the ultrasonic sensor falls below a predetermined threshold value and the printing conditions for the print medium are not suitable for printing envelopes, the control means for stopping the transfer of the print medium is provided. A transport device characterized by the fact that. If the level of ultrasonic waves detected by the ultrasonic sensor is below the predetermined threshold value and the printing conditions for the printing medium are not suitable for printing envelopes, double feeding in a state where two or more sheets are overlapped is performed. The transport device according to claim 1, wherein the transport device is said to have occurred. A medium type determining means for determining the type of the printed medium to be conveyed is provided.
When the level of ultrasonic waves detected by the ultrasonic sensor is equal to or higher than the predetermined threshold value, the medium type determining means of the medium to be printed has the printing conditions suitable for printing the envelope. The transport device according to claim 1 or 2, wherein the type is determined to be a sheet. Equipped with multiple storage trays at the upstream end of the transport path
The control means stops the transfer of the printing medium when the printing condition corresponds to the first condition suitable for printing a sheet although it is not suitable for printing an envelope.
The medium type determining means is
i) The printing conditions are the second printing conditions suitable for printing both sheets and envelopes.
ii) The job including the printing conditions selects a storage tray that has not yet supplied one sheet after the printing medium is stored.
iii) A level of ultrasonic waves below the predetermined threshold is detected for the printable medium first supplied from the storage tray.
The transport device according to any one of claims 1 to 3, wherein the type of the medium to be printed to be transported on the transport path is an envelope. The printing unit includes a transfer unit that executes printing by an electrophotographic method and transfers an image on an image carrier to the printing medium at a transfer position.
It is provided with a fixing portion for fixing the image transferred to the print medium to the print medium.
When the medium type determining means uses an envelope as the type of the medium to be printed to be conveyed on the transport path, the transfer unit is instructed to perform transfer using a higher voltage than transfer to the sheet, and the transfer is performed on the sheet. The transport device according to claim 4, wherein the fixing unit is instructed to perform thermal fixing with a high fixing temperature as a target temperature. A predetermined time elapses from the supply sensor provided in each of the plurality of storage trays and detecting the supply start timing when the corresponding storage tray starts supplying the printable medium and the detected supply start timing. The ultrasonic sensor is provided with a sensor driving means for starting the driving of the ultrasonic sensor.
The transport distance from each storage tray to the ultrasonic sensor is different.
The predetermined time according to any one of claims 4 to 5, wherein the predetermined time is determined according to the length of the transport distance that varies depending on which storage tray contains the printing medium. Transport device. In the transport path, a feeding roller for feeding out the printable medium stored in the storage tray, a supply roller for supplying the fed-out printable medium to the downstream side, and a timing for feeding the supplied printable medium to the transfer position. There is a timing roller to take the picture.
The ultrasonic sensor was installed at a position downstream of the supply roller and upstream of the timing roller in the transport direction of the printable medium in the transport path, and was detected by the ultrasonic sensor. If the ultrasonic level is below a predetermined threshold and the printing conditions are not suitable for printing an envelope, the control means may be applied to the printing medium before the printing medium reaches the timing roller. The transport device according to any one of claims 1 to 5, wherein the transport is stopped. At a position downstream of the installation location of the ultrasonic sensor in the transport path, there is a guide member that guides the printing medium to a timing roller further downstream.
Of the received signals emitted by the receiving element of the ultrasonic sensor, a partial waveform after the time when the tip of the printing medium collides with the guide member is extracted, and the ultrasonic wave is calculated from the extracted partial waveform. The transport device according to claim 7, wherein the transport device is characterized by the above. The printing conditions that are not suitable for printing the envelope are an instruction for aggregate printing in which images of different pages are aggregated on one side of one sheet, or an image is formed on both sides of one sheet. The transport device according to any one of claims 1 to 8, wherein the transfer device includes instructions for double-sided printing. Claims 1 to 9 are characterized in that, in the printing conditions unsuitable for printing the envelope, after printing on one sheet, an instruction for post-processing to be performed on the printed sheet is added. The transport device according to any one of. The transport device according to claim 10, wherein the post-processing instruction is an instruction to bind the edge of the printed sheet. The transport device according to claim 10, wherein the post-treatment instruction is an instruction to perforate the edge of the printed sheet. The transport device according to claim 10, wherein the post-processing instruction is an instruction to Z-fold the printed sheet. The transport device according to claim 10, wherein the post-processing instruction is an instruction to fold or saddle stitch the sheet. The transport device according to claim 10, wherein the post-processing instruction is an instruction to attach a cover to a sheet to be printed by adding another sheet to be a cover to create a sheet bundle. The transport device according to claim 10, wherein the post-processing instruction is cutting of a sheet on which an image related to a printing request is formed. An image forming apparatus including the transport device according to any one of claims 1 to 16 and a printing unit.

Images