JP2010208824A - Printer and printing control method - Google Patents

Abstract

In a printing apparatus equipped with a VR as a paper width detecting means, the deterioration of the VR can be appropriately detected and corrected to improve the detection accuracy of the paper width.
A printing apparatus that feeds paper from a paper feed path FR to a transport path, forms an image on the normal transport path, and performs a printing process, the paper being fed through the paper feed path FR A detection result by the in-tray sensor (VR) 182 for detecting the width of the sheet, a conveyance sheet width sensor (CIS) 184 for detecting the width of the sheet conveyed in the normal conveyance path CR, and a detection result by the in-tray sensor (VR) 182 A comparison unit 332b that compares the detection result by the conveyance sheet width sensor 184 and a notification unit 332e that notifies the comparison result by the comparison unit are provided.
[Selection] Figure 1

Description

  The present invention relates to a printing apparatus and a printing control method for supplying a sheet from a sheet feeding unit to a conveyance path, forming an image on the conveyance path, and performing a printing process.

  2. Description of the Related Art Conventionally, in a printing apparatus such as an ink jet, it is known that a printing paper width is detected using a variable resistance detector (VR) built in a paper feed tray. In this detection by VR, the side fence for aligning the side surfaces of the stacked sheets is slid, and the distance from the side edge of the sheet to the side fence at the other end, that is, the electrical resistance corresponding to the sheet width is detected by VR. Thus, the paper width is detected (for example, Patent Document 1).

JP 2006-52054 A

  However, conventionally, in VR, when the side fence is slid, the resistance film of the variable resistance is scraped to cause wear and deterioration, and the resistance value changes to lower the detection accuracy of the paper width. In this case, since the paper width is not accurately measured, there is a problem in that the printed matter is affected or a paper discharge jam is likely to occur. On the other hand, since the side fence is manually operated by the user, even if the VR detects an abnormal value, it is determined whether it is due to a VR failure or a user's erroneous operation. However, there is a limit to the improvement of the detection accuracy described above.

  Accordingly, the present invention solves the above-described problems. In a printing apparatus equipped with a VR as a paper width detecting means, the deterioration of the VR can be properly detected and corrected to detect the paper width. It is an object of the present invention to provide a printing apparatus and a printing control method capable of improving accuracy.

  In order to solve the above-described problems, the present invention detects a width of a sheet supplied from a sheet feeding unit to a conveyance path, and performs printing processing by forming an image in the conveyance path based on the detected sheet width. A first sheet width detecting unit configured to detect a width of a sheet fed by the sheet feeding unit; a second sheet width detecting unit configured to detect a width of the sheet conveyed along the conveying path; A comparison means for comparing the detection result of the first paper width detection means with the detection result of the second paper width detection means, the first paper width detection means being slid in the paper width direction, The second paper width detecting means receives the reflection of the light applied to the paper, based on the received reflected light. The paper width is detected.

  According to the present invention, in order to compare the paper width detection on the paper feeding means side with the detection of the paper width in the transport path, the paper width setting on the paper feed side and the paper width actually transported are compared. If, for example, it is detected that the side fence of the paper feed tray is positioned larger than the printing paper due to an erroneous operation by the user, or the paper detection accuracy decreases due to wear due to the sliding of the VR. Can be detected.

  In the above invention, the first paper width detecting means is a variable resistance detector (VR) having a pair of measuring electrodes that are slid in the paper width direction and measure a separation distance according to the paper width by an electric resistance value. The second sheet width detecting unit receives reflection of light irradiated on the sheet, photoelectrically converts the received reflected light, and outputs an analog image signal. (CIS: Contact Image Sensor) is preferable. Moreover, when comparing the detection results, it is preferable to count the number of times the measurement electrode slides and calculate the comparison results according to the counting results.

  In this case, in order to compare the detection of the sheet width by the sheet width detector using an electric resistance such as VR on the sheet feeding means side and the detection of the optical sheet width such as CIS in the conveyance path. The deterioration of VR, which is relatively easy to break, can be compensated by CIS. At this time, when comparing the detection results, the number of sliding of the measurement electrode of the VR is counted, and the comparison result is reflected in the comparison result, so that a more accurate comparison can be performed.

  In the above invention, it is preferable to divide the sliding range of the measurement electrode based on the paper width corresponding to the paper size and to count the sliding frequency for each of the divided sections. Since the side fence operation by the user is often performed with the change of the paper size, according to such an invention, the sliding frequency in accordance with the user's operation tendency can be easily measured. .

  In the above invention, while the measurement electrode is energized, the number of times the measurement electrode slides according to the change in the electrical resistance value is counted. Memorize the position of the electrode for measurement, compare this memorized position with the position of the electrode for measurement when energization is resumed, and if the position has changed, add the predetermined number of times to the number of sliding It is preferable to do. Since the user can operate the side fence while the power of the printing apparatus is OFF and the power supply to the measurement electrode is cut off, according to such an invention, the sliding frequency can be measured. It is possible to estimate a user operation when the power cannot be turned off, and to measure the sliding frequency more accurately.

  In the above invention, when the comparison means determines that the detection result by the first paper width detection means is different from the detection result by the second paper width detection means, based on the detection result by the second paper width detection means. Thus, it is preferable to correct the detection result of the first paper width detection means. In this case, even if the first paper width detecting means such as VR is deteriorated, the correction is made by using the detection result obtained by the second paper width detecting means such as CIS, and so on. The detection value can be made appropriate, the paper width detection accuracy can be prevented from being lowered, and if the deterioration is slight, the use of the apparatus can be continued without maintenance.

  In the said invention, it is preferable to have an alerting | reporting means to alert | report the said comparison result. In this case, for example, confirming when the side fence of the paper feed tray does not match the paper width, finding the damage of the paper width detection means, and instructing that the contents of the print processing settings should be changed in a timely manner. Notification can be made, and erroneous operation due to user's erroneous operation or VR degradation can be prevented in advance.

  In the above invention, it is preferable to change the printing process when it is determined that the detection result by the first paper width detection means is different from the detection result by the second paper width detection means.

  Specifically, the change in the printing process is that the at least first sheet is transported at a low speed based on a user operation, and the detection result by the first sheet width detecting unit is not used. For example, the print processing may be executed based only on the detection result by the paper width detection means.

  As another change of the printing process, the conveyance path is set as a circulation path so that image formation can be performed a plurality of times. The detection result by the first sheet width detection unit and the detection result by the second sheet width detection unit. Are determined to be different from each other, the conveyance of at least the first sheet is circulated based on the user operation, and the printing process is executed only based on the detection result by the second sheet width detecting unit. Also good.

  As the user operation here, for example, maintenance work such as component replacement is performed in order to eliminate the cause of the difference between the detection results of the first and second paper width detection means, or the second operation described above. For example, a selection operation of whether to approve the execution of the printing process based only on the detection result by the sheet width detection unit of the printer may be considered.

  In these cases, it is expected that one of the detection means has deteriorated. However, by changing the printing process, the deterioration of the one detection means is complemented by the other detection means, and the printing operation is continued. Can be selected based on the user's intention. At this time, the detection accuracy is reduced because only the detection value obtained by the other detection means is used. However, the total accuracy can be kept constant by reducing the conveyance speed or circulating in the circulation path. it can.

  As described above, according to the present invention, in a printing apparatus equipped with a paper width detector such as a VR that wears and deteriorates, the deterioration of the paper width detector can be properly detected and corrected to detect the paper width. In addition to improving accuracy, it is possible to determine an erroneous operation by the user and perform appropriate notification, and as a result, it is possible to optimize printing operation and conveyance control.

1 is a diagram illustrating a schematic configuration of a printing apparatus according to an embodiment. It is the figure which showed typically the conveyance path of the printing apparatus which concerns on embodiment. It is a block diagram showing a functional module related to a monitoring process of a paper width sensor in the printing apparatus according to the embodiment. 5 is a flowchart illustrating a print processing operation (during normal operation) based on monitoring by a paper width sensor in the printing apparatus according to the embodiment. 6 is a flowchart illustrating a print processing operation (when the comparison value is abnormal) based on monitoring by a paper width sensor in the printing apparatus according to the embodiment. 6 is a flowchart illustrating a print processing operation (when VR is damaged) based on monitoring by a paper width sensor in the printing apparatus according to the embodiment. It is a graph which shows the relationship between the division | segmentation of the paper width at the time of counting the frequency | count of sliding of VR in embodiment, and a count value. FIG. 6 is a graph showing a relationship between a sheet width classification and a count value in a range of an irregular sheet when counting the number of VR slides in the embodiment.

  Exemplary embodiments of a system according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a conceptual diagram showing an overall configuration of a system according to the present embodiment.

(Overall configuration of printing device)
A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating an outline of a printing paper conveyance path in the printing apparatus 100 according to the present embodiment. The printing apparatus 100 is a printing apparatus that supplies paper from the paper feed system conveyance path FR to the normal conveyance path CR and forms an image on the normal conveyance path CR to perform a printing process. The printing apparatus 100 mainly includes a paper feed mechanism and a circulation conveyance mechanism. And a paper discharge mechanism and a reversing mechanism.

  First, as illustrated in FIG. 1, the printing apparatus 100 includes a side sheet feed stand 120 exposed to the outside of the side surface of the casing and a plurality of sheet feeding units provided inside the casing as a sheet feeding mechanism that supplies printing paper. Trays (130a, 130b, 130c, 130d). A paper discharge port 140 is provided as a paper discharge mechanism for discharging printed printing paper.

  In the present embodiment, the printing apparatus 100 includes a plurality of ink heads that extend in the paper width direction and have a large number of nozzles, and prints in units of lines by discharging black or color ink from the respective ink heads. An inkjet line color printer that forms a plurality of images on a recording sheet on a belt so as to overlap each other is provided.

  Printing paper fed from one of the side paper feed tray 120 and the paper feeding tray 130 is conveyed along a paper feeding system conveyance path FR in the housing by a driving mechanism such as a roller, and the printing paper It is guided to the resist portion R which is the reference position of the head portion. A head unit 110 having a plurality of print heads is provided further on the registration direction R in the transport direction side. The printing paper is image-formed line by line with ink ejected from each printing head while being conveyed at a speed determined by printing conditions by a conveying belt 160 provided on the opposite surface of the head unit 110.

  The printed printing paper is further conveyed in the housing by a driving mechanism such as a roller. In the case of single-sided printing in which printing is performed only on one side of the printing paper, the paper is guided to the paper discharge port 140 and discharged as it is, and the print surface is lowered to a paper discharge table 150 provided as a receiving tray for the paper discharge port 140. It will be loaded. The paper discharge table 150 has a tray shape protruding from the housing, and has a certain thickness. The paper discharge table 150 is inclined, and the printing paper discharged from the paper discharge port 140 is naturally arranged and overlapped by a wall formed at a position below the inclination.

  In the case of double-sided printing in which printing is performed on both sides of the printing paper, the front side (the first printed side is referred to as “front side” and the next printed side is referred to as “back side”) is not guided to the paper discharge outlet 140 at the end of printing. In addition, it is transported in the housing. For this reason, the printing apparatus 100 includes a switching mechanism 170 for switching the conveyance path for backside printing. The printing paper that has not been discharged by the switching mechanism 170 is drawn into the switchback path SR. In the switchback route SR, the paper is delivered from the normal conveyance path CR, and the switchback is performed to reverse the front and back of the paper by reciprocating the paper and returning it to the normal conveyance path CR.

  Then, by a driving mechanism such as a roller in the paper re-feeding system path, it is guided again to the registration unit R via the switching mechanism 172, and the back side is printed by the same procedure as that for the front side. The printing paper on which the back side is printed and the images are formed on both sides is guided to the paper discharge port 140 and discharged, and is stacked on a paper discharge table 150 provided as a receiving base of the paper discharge port 140. . In the present embodiment, the switchback in the switchback path SR at the time of double-sided printing is performed using the space provided in the paper discharge tray 150. The space provided in the paper discharge tray 150 is configured to be covered so that the printing paper cannot be taken out from the outside at the time of switchback.

  In the printing apparatus 100, one-side printed printing paper is also transported to the registration portion R, which is the reference position of the leading portion of the fed printing paper, during duplex printing. For this reason, a junction point where the transport path of the fed printing paper and the path through which the back-side printing paper is circulated is joined immediately before the registration portion R.

  Based on this merging point, the path on the paper feed mechanism side is referred to as a paper feed system transport path FR, and the other path is referred to as a normal transport path CR. FIG. 2 is a diagram schematically showing the sheet feeding system conveyance path FR, the normal conveyance path CR, and the switchback path SR. For simplicity, the number of rollers constituting the drive unit is omitted as appropriate.

  In the paper feed system conveyance path FR, the side paper feed driving unit 220 for feeding paper from the side paper feed tray 120 and the paper feed from the paper feed trays 130 (130a, 130b, 130c, 130d) are provided. A tray 1 driving unit 230a, a tray 2 driving unit 230b,. These constitute a paper feeding means for feeding paper to the registration unit R. Each of the paper feed trays 120 and 130 (130a, 130b, 130c, and 130d) includes in-tray sensors 182, 183a, 183b,... As first paper width detection means for detecting the width of the paper in the tray. ing. Various sensors can be used as the in-tray sensors 182, 183 a, 183 b... In this embodiment, the variable resistors provided in the pair of side fences 121 a and 121 b that slide in the paper width direction in the tray. It becomes a detector (VR: Variable Resistor).

  That is, a pair of measurement electrodes is attached to the side fences 121a and 121b, and the VR measures the separation distance between the side fences 121a and 121b according to the paper width by the electric resistance value between the electrodes. . The measured electrical resistance value is sent to the comparison unit 332b.

  Further, any of the driving units (tray 1 driving unit 230a, tray 2 driving unit 230b...) In the above-described paper feeding system conveyance path FR includes a driving mechanism constituted by a plurality of rollers and the like. Are taken one by one and conveyed in the direction of the registration portion R. Each drive unit can be driven independently, and necessary drive unit operations are performed in accordance with a paper feed mechanism that feeds paper. In particular, in the present embodiment, the drive unit of the paper feed system transport path FR is configured to adjust the transport speed of the paper on the paper feed system transport path FR between the registration unit R and the paper feed system transport path FR. A driving roller 290 is provided as a deceleration driving means.

  In addition, a plurality of conveyance sensors are arranged in the paper feeding system conveyance path FR so that a conveyance jam in the paper feeding system conveyance path FR can be detected. That is, each conveyance sensor is a sensor that detects the presence or absence of printing paper or the leading edge of printing paper. For example, a plurality of conveyance sensors are arranged at appropriate intervals on a conveyance path, and a conveyance sensor provided on the paper feeding side is provided. If the conveyance sensor on the conveyance direction side does not detect the printing paper within a predetermined time after detecting the printing paper, it can be determined that the conveyance jam has occurred.

  Among these transport sensors, the CIS 184 disposed downstream of the registration unit R that feeds out the paper functions as a second paper width detection unit that detects the width of the paper being transported. The reflected light is received, the received reflected light is photoelectrically converted, and an analog image signal is output. The output image signal is sent to the comparison unit 332b.

  The normal conveyance path CR is an annular circulation conveyance path, and an image is formed on the upper surface of the sheet on the normal conveyance path CR. The normal conveyance path CR includes a registration driving unit 240 that guides printing paper to the registration unit R, a belt driving unit 250 that drives the conveyance belt 160 provided on the opposite surface of the head unit 110 to move endlessly, and a conveyance direction side. The first upper surface transport driving unit 260 and the second upper surface transport driving unit 265, the upper surface discharge driving unit 270 that guides the printed paper to the paper discharge port 140, and the printing paper for back side printing on the switchback path SR. A switchback path driving unit 280 is provided that pulls in, reverses, and guides it to the junction. Each drive unit includes a drive mechanism composed of one or a plurality of rollers and the like, and conveys printing paper one by one along the conveyance path. Each drive unit can be driven independently, and necessary drive unit operations are performed in accordance with the conveyance status of the printing paper.

  Further, a plurality of transport sensors are also arranged on the normal transport path CR so that a transport jam in the normal transport path CR can be detected. Further, it is possible to confirm that the printing paper is properly conveyed also in the registration portion R. In the normal conveyance path CR, a conveyance sensor is provided corresponding to the drive unit, and it is possible to specify in which drive unit of the normal conveyance path CR the conveyance jam has occurred.

  The switchback path SR is branched and connected to the normal transport path CR, and the paper is transferred from the normal transport path CR, and the paper is reciprocated (switched back) and returned to the normal transport path CR to reverse the front and back of the paper. This switchback path SR can be transported at a speed different from that of the normal transport path CR. When the paper is taken over from the normal transport path CR, the switchback path SR can be accelerated or decelerated, The stopping time can be extended or shortened.

  In this embodiment, after a certain printing paper is fed, the next printing paper is not fed after waiting for printing to be performed on the printing paper and discharged. Before the printing paper is discharged, subsequent printing paper can be fed and printed continuously at a predetermined interval.

  More specifically, in double-sided printing in this apparatus, after printing on the head unit 110, the paper circulates through the normal conveyance path CR, and the front and back are reversed via the switchback path SR. It returns and is ejected after the back side is printed. In such double-sided printing, the paper whose front and back are reversed via the switchback path SR is inserted between the papers on which the front surface is printed. Therefore, in normal scheduling at the time of duplex printing, a space is secured in advance so as to secure a position where the sheet returned from the switchback path SR is inserted when feeding the sheet on the front side. Thereby, in this apparatus, printing on the front surface and printing on the back surface can be performed in parallel, and half the productivity can be ensured with respect to single-sided printing.

  The conveyor belt 160 is wound around a driving roller 161 and a driven roller 162 disposed at the front end and the rear end of the surface facing the head unit 110, and rotates in the clockwise direction in the drawing. On the upper surface of the conveyor belt 160, four ink heads of yellow (Y), magenta (M), cyan (C), and black (K) are arranged side by side along the belt moving direction, and a plurality of images are arranged. The head units 110 that form color images are arranged so as to face each other.

  As illustrated in FIG. 1, the printing apparatus 100 includes an arithmetic processing unit 330. The arithmetic processing unit 330 is configured by a processor such as a CPU or DSP (Digital Signal Processor), memory, hardware such as other electronic circuits, software such as a program having the function, or a combination thereof. Various functional modules are virtually constructed by appropriately reading and executing a program, and various functional modules for processing related to image data, operation control of each unit, and user operations are constructed by each constructed functional module. Process. In addition, an operation panel 330a is connected to the arithmetic processing unit 330, and an instruction and a setting operation by a user can be received through the operation panel 330a.

(Configuration of arithmetic processing unit)
The monitoring control of the sensor relating to the detection of the paper width and the drive control relating thereto in the present embodiment are performed by the arithmetic processing unit 330 to perform signal processing from various sensors, transport path driving of the head unit 110, each drive motor, each switching mechanism, and the like. This is done by controlling the operation of the means.

  FIG. 3 is a block diagram showing functional modules related to printing control by paper width detection in the arithmetic processing unit 330. As shown in FIG. 3, the arithmetic processing unit 330 mainly includes a sensor monitoring unit 332, an image data receiving unit 333, a print control unit 331, a conveyance path drive control unit 334, and a scheduling unit 335. .

  The image data receiving unit 333 is a communication interface that receives job data, and transfers image data included in the received job data to the print control unit 331. The print control unit 331 is an arithmetic processing unit that performs digital signal processing specialized for image processing, and is a module that performs image data conversion necessary for printing and executes printing. The print control unit 331 includes an image formation control unit 331a and a color conversion circuit 331b.

  The image formation control unit 331a is a module that controls the driving of the ink heads of each color and the operation of the driving unit of the conveyance path, and controls the entire image formation processing. The image formation control unit 331a has the timing and printing speed according to the scheduling of the scheduling unit 335. Perform image formation. The color conversion circuit 331b is a circuit that converts an RGB print image into a CMYK print image, and causes the image formation control unit 331a to perform printing based on the print image for each color.

  On the other hand, the sensor monitoring unit 332 displays the measurement results obtained by the in-tray sensors (first paper width detection means) 182, 183a, 183b, and the measurement results obtained by the transport paper width sensor 184 (second paper width detection means). It is a module that acquires and compares them, and monitors the occurrence of abnormal values by users and abnormal values due to sensor failures. Specifically, the sensor monitoring unit 332 includes a sliding counting unit 332a, a comparison unit 332b, a correction unit 332d, a mode setting unit 332c, and a notification unit 332e.

  The comparison unit 332b is a module that receives the detection results from the in-tray sensors (VR) 182 to 183b and the detection result from the conveyance paper width sensor (CIS) 184 and compares them. The comparison result here is sent to the correction unit 332d and the notification unit 332e. The comparison unit 332b has table data that can calculate the sheet width from the resistance value with respect to the detection values from the in-tray sensors (VR) 182 to 183b. By referring to this table data, The sheet width is acquired from the resistance values from the sensors (VR) 182-183b.

  The sliding counting unit 332a is a module that counts the number of times the measurement electrode of the side fence 121a slides. Specifically, the sliding counting part 332a divides the sliding range with respect to the paper width of the specification range, and changes the resistance value. The number of times of sliding is counted in each divided section, the section and the count value are associated and recorded, and the sliding frequency for each section (sliding range) is calculated and input to the comparison unit 332b. The comparison unit 332b calculates a comparison result according to the counting result by the sliding counting unit 332a.

  The notification unit 332e is a module that notifies the user of the comparison result by the comparison unit 332b and the correction unit 332d through the operation panel 330a. Examples of the notification method include displaying an error message on the operation panel 330a, turning on an error display LED, and outputting sound such as a beep sound.

  The sliding value counting method of the in-tray sensors (VR) 182, 183a, and 183b by the sliding counting unit 332a is divided at intervals according to the standard size, and the number of times of passing or reaching the respective divisions is determined for each division. The count value is increased by the value set in the section at the detected timing. This count is always performed regardless of whether the power is on or off. That is, when the power supply is ON, the number of sliding times of the VR is counted by confirming at any time that the resistance value changes due to the sliding of the side fence 121a.

  Specifically, while this power supply is ON, as shown in FIG. 7, it is divided into resistance values according to the standard size, and when it passes or reaches that section, it is set to that section. Count the number of sliding for each category. For example, as shown in FIG. 7, when the paper size is from the minimum specification to B4, it passes through the sections of each paper size (A6, B5, A4, B4). Add one by one ((a) in FIG. 7).

  When the paper size is in the range from B4 to A3, 1 is added to the section N-1 (the section of B4 and A3) and the section N (the section of A3 and the maximum specification) (FIG. 7). (B)), and addition is not performed when the paper size is in the range from A3 to an indeterminate form (size between A3 and the maximum specification) ((c) in FIG. 7). When the paper size is indefinite (size between A3 and maximum specification), 1 is added to the category N as in A3 ((d) in FIG. 7). In this way, by changing the count number according to the size, it is possible to detect wear deterioration due to sliding with higher accuracy than simply counting the number of reciprocations.

  In addition, when the moving direction is changed within the same section in the range of A3 to the maximum specification, 1 is added to the number of sliding times of the section ((e) in FIG. 8). At this time, in the range of A3 to Amorphous 2, 1 is added to the section N when passing through A3 ((f) in FIG. 8). Further, when the moving direction is changed from the indeterminate form 2 to the indeterminate form 1 (the voltage V becomes smaller), 1 is added to the section N. Further, when the moving direction is changed from the indeterminate form 1 to the indeterminate form 2, 1 is added to the section N ((g) in FIG. 8).

  As described above, in the present embodiment, the number of times of sliding in each section is added every time each section is passed, and in the range of the irregular sheet, the irregular range (when the moving direction is changed) Here, by adding to the category N), the sliding frequency can be measured with higher accuracy.

  On the other hand, when the power is turned off, the resistance values of the in-tray sensors (VR) 182, 183a, and 183b when the power is turned off are stored in a non-volatile memory. The resistance value of VR is acquired, the resistance value when the power is turned off is compared with the resistance value when the power is turned on, and the difference is obtained. As a result of the comparison, if the difference value is within the specified value, it is determined that the VR has not been slid. If the difference value is greater than the specified value, the VR has been slid during the power OFF. Judgment is made, and 2 is added to the number of sliding times of all sections.

  The reason for this is that when VR is displaced when the power is turned on after the power is turned off, it is estimated that the VR is displaced at least once in the range from the minimum specification to the maximum specification. More specifically, when the paper size is at the minimum specification when the power is turned off, if the fence is moved to the maximum specification, the number of slides in all sections becomes +1. Next, when the fence moves from the maximum specification to the minimum specification, the number of slides in all sections becomes +1. Therefore, when the paper size is different when the power is turned off, it is assumed that the range from the minimum specification to the maximum specification is reciprocated once, and 2 is added in all the sections. A value obtained by adding 2 to all the sections is a value corresponding to the maximum movement amount, and is a slightly estimated value. As a result, even if it is unclear how the sliding is performed when the power is turned off, it is possible to estimate the approximate sliding frequency that is slightly overestimated.

  When the comparison unit 332b determines that the detection results of the in-tray sensors (VR) 182 to 183b are different from the detection results of the conveyance paper width sensor (CIS) 184, the correction unit 332d performs the conveyance paper width sensor (CIS). This module corrects the detection results of the in-tray sensors (VR) 182 to 183b based on the detection result by 184. The corrected comparison result is sent to the scheduling unit 335.

  The mode setting unit 332c is a module that receives an operation signal from the user from the operation panel 330a and sets a transport operation control mode based on the user operation. The mode setting unit 332c analyzes the received operation signal and controls the transport operation according to the user operation. Get the mode. According to the transport operation control mode set here, monitoring processing and error processing in the sensor monitoring unit 332 are executed.

  As described above, the scheduling unit 335 is a module that determines the speed, order, and timing related to paper feeding, image formation, and conveyance of paper that is printed on the front surface and paper that is turned upside down through the switchback path SR. . The scheduling unit 335 also has a function of correcting the sheet interval by adjusting the speed, order, and timing related to sheet feeding, image formation, and conveyance based on the sensor monitoring result acquired from the correcting unit 332d. ing. In other words, when the comparison unit 332b determines that the detection results from the in-tray sensors (VR) 182 to 183b are different from the detection results from the conveyance sheet width sensor (CIS) 184, the conveyance path drive control unit 334 and the print control unit It also functions as a print control unit that performs control to change the print processing on the 331.

  As a change of the printing process here, at the start of printing, the size of the sheet width is confirmed by the conveyance sheet width sensor (CIS) 184 by passing the first sheet, and the subsequent printing process is performed based on the confirmed sheet width. continue. As the size check by passing the first sheet, the first sheet is conveyed at a low speed, and the printing process is executed in parallel while confirming the sheet width, or the printing is performed without using the circulation conveyance. It is conceivable that the sheet is circulated and only the sheet width is confirmed by the conveyance sheet width sensor (CIS) 184 at the first sheet, and after the sheet width is confirmed, the printing process is executed at a normal speed. At this time, when it is determined that the detection result by the in-tray sensors (VR) 182 to 183b is different from the detection result by the conveyance paper width sensor (CIS) 184, the operation panel 330a uses these paper width detection means. Whether to perform maintenance work such as component replacement in order to eliminate the cause of the difference in the detection results of the above, or whether to approve the execution of the printing process based only on the detection results of the conveyance paper width sensor (CIS) 184 described above Prompt for selection.

  The sensor monitoring unit 332 detects the occurrence of a jam by monitoring detection results from sensors other than the in-tray sensors (VR) 182, 183a, 183b and the conveyance paper width sensor (CIS) 184. Yes. As a change in the printing process described above, when the printing process is changed without exchanging the VR according to the intention of the user, and the printing process is continued only by detecting the sheet width by the conveying sheet width sensor (CIS) 184, When the jam occurs frequently, the notifying unit 332e notifies an error to that effect that the conveyance paper width sensor (CIS) 184 itself is likely to be broken.

  The transport path drive control unit 334 is a transport control module that controls operations of transport operation control in the normal transport path CR, the paper feed system transport path FR, and the switchback path SR according to the scheduling of the scheduling unit 335.

(Print control method)
By operating the printing apparatus having the above configuration, the following print control method can be implemented. FIGS. 4 to 6 are flowcharts showing operations during the printing process of the printing apparatus according to the present embodiment.

  First, when image data is acquired by receiving job data or the like (S101), the print control unit 331 performs development of the image data and color conversion by the color conversion circuit 331b, and conveyance scheduling is performed according to the contents of the job. Perform (S102). Then, a predetermined paper feed tray is selected according to the paper size specified in the job data, and the size of the paper in the paper feed tray is measured by the tray sensors (VR) 182, 183a, and 183b (S103). Then, paper feeding is started according to the scheduling (S104).

  During normal operation, as shown in FIG. 4, after the start of printing, while the first sheet is being conveyed, the conveyance sheet width sensor (CIS) 184 measures the sheet width being conveyed ( In step S105, the sheet width detection values of the in-tray sensors (VR) 182, 183a, and 183b and the conveyance sheet width sensor (CIS) 184 are compared (S106), and it is confirmed whether the comparison result is within a specified value. If it is within the specified value (“Y” in S106), printing is continued (S107). If it is not specified (“N” in S106), printing is stopped (S108), and printing is stopped as shown in FIG. The processing shifts to the time processing ("B" in FIGS. 4 and 5).

  As shown in FIG. 5, when the detected paper width value differs greatly between the in-tray sensors (VR) 182, 183a, 183b and the transported paper width sensor (CIS) 184, the side An instruction is given to align the fence to the size of the printing paper (S201). Thereafter, the sheet width detection value by the in-tray sensors (VR) 182, 183a, 183b is confirmed (S202), and whether the number of sliding times of the in-tray sensors (VR) 182, 183a, 183b exceeds the specified value D or not. Is determined (S203). If the number of sliding times of the in-tray sensors (VR) 182, 183a, 183b is less than the specified value D ("N" in S203), the sheets of the in-tray sensors (VR) 182, 183a, 183b reacquired in S202 Based on the detected width value and the conveyance paper width sensor (CIS) 184, it is confirmed whether or not the side fence of the paper feed tray is aligned larger than the size of the printing paper (S204). When the side fences of the paper feed tray are aligned larger than the size of the printing paper (S205), the operation returns to the normal operation (“A” in FIGS. 4 and 3).

  When the in-tray sensors (VR) 182, 183a, 183b have a large number of sliding times (“Y” in S203), or the in-tray sensors 182, 183a, 183b have a small number of sliding times, the in-tray sensors 182, 183a, If the sheet width detection values of 183b and the conveyance sheet width sensor (CIS) 184 are not specified ("N" in S204), the sheet is passed (S206), and the sheet in the conveyance path is conveyed by the conveyance sheet width sensor (CIS) 184. While detecting the width (“Y” in S208), the detection values of the in-tray sensors (VR) 182, 183a, 183b and the conveyance paper width sensor (CIS) 184 are compared (S208), and the comparison value is a predetermined specified value. If it is smaller than C, the side fence of the paper base has been set larger than the size of the printing paper, or step S10. After printing stops in, the different sheets is placed size (S209), returns to normal operation ( "A" in FIG. 4 and FIG. 3).

  In step S208, when the comparison value is larger than the predetermined specified value C (“N” in S208), the sheet is passed and the sheet width is determined from the sheet width detection value of the conveyance sheet width sensor (CIS) 184. Along with (S210), the sheet width detection value An corresponding to the resistance value or voltage value detected in the VR table is called (S211), the tray sensors (VR) 182, 183a, 183b, and the conveyance sheet width sensor (CIS) 184. The paper width detection values by are compared (S212). If the comparison value is equal to or less than the specified value E (“Y” in S212), the table data of the in-tray sensors (VR) 182, 183a, 183b are corrected and updated (S213), and the normal operation is resumed (FIG. 4 and FIG. 4). “A” in FIG. 3).

  As a correction method, the tray width sensor (VR) 182, 183a, 183b is based on the detection value obtained by the transport sheet width sensor (CIS) 184 in step S210 and the tray width sensor (VR). ) The detection values of 182, 183a and 183b are calibrated, the correlation between the voltage or resistance value and the paper width is corrected, and the table data is updated to reflect the correction result.

  If it is determined in S212 that the comparison value is greater than the specified value E ("N" in S212), the in-tray sensors (VR) 182, 183a, 183b are damaged (S214). The process proceeds to step S302 ("C" in FIGS. 5 and 6). In step S302, assuming that the in-tray sensors (VR) 182, 183a, 183b are damaged, an error is notified to prompt the user to replace the in-tray sensors (VR) 182, 183a, 183b (S301). Here, the user is inquired whether or not to continue printing in this state without performing VR part replacement (S302). As a method for inquiring to the user, for example, a message indicating that the VR component may be damaged is displayed on the operation panel 330a, or voice output is given. If the user wishes to replace the VR ("N" in S302), the VR is replaced (S304), table data of the replaced VR is created (S307), The number of movements is reset (S308), and then the normal operation is resumed.

  Also, in step S302, if the user performs an operation to that effect without wishing to replace the part, and if the user performs an operation to that effect, the printing operation is restricted according to the user operation, and the printing process is continued. (S303). This user operation is executed, for example, by displaying an operation button for continuing the printing process without replacing parts on the touch panel of the operation panel 330a, and pressing the user down.

  As a limitation of the printing operation here, at the start of printing, the size of the sheet width is confirmed by the conveyance sheet width sensor (CIS) 184 by passing the first sheet, and subsequent printing processing is performed based on the confirmed sheet width. continue. As the size check by passing the first sheet, the first sheet is conveyed at a low speed, and the printing process is executed in parallel while confirming the sheet width, or the printing is performed without using the circulation conveyance. It is conceivable that the sheet is circulated and only the sheet width is confirmed by the conveyance sheet width sensor (CIS) 184 at the first sheet, and after the sheet width is confirmed, the printing process is executed at a normal speed.

  Thereafter, the printing process is restricted and the printing process is continued. At this time, the sensor monitoring unit 332 is based on the detection results from the sensors other than the in-tray sensors 182, 183 a, 183 b and the conveyance sheet width sensor 184. The occurrence of a jam is detected (S305). As a change in the printing process described above, when printing is continued only by detecting the paper width by the transport paper width sensor (CIS) 184 without exchanging the VR according to the intention of the user, when jams occur frequently in the transport path, Since there is a high possibility that the conveyance paper width sensor (CIS) 184 itself is out of order, the notification unit 332e notifies the error to that effect and disables printing (S306).

(Action / Effect)
According to this embodiment, in order to compare the detection of the paper width using an electrical resistance such as VR and the detection of the optical paper width by the transport paper width sensor (CIS) 184 in the transport path, Monitors the comparison value between the paper width setting on the paper feed tray and the actual paper width being transported, and detects that the side fence on the paper feed tray is positioned larger than the print paper due to user error. Or a decrease in paper detection accuracy caused by wear due to sliding of the in-tray sensors (VR) 182, 183a, 183b.

  Further, in this embodiment, since the comparison result by the comparison unit 332b is notified by the notification unit 332e, confirmation when the side fence of the sheet feeding table does not match the sheet width, and sensors in the tray (VR) 182, 183a , 183b or the conveyance paper width sensor (CIS) 184, an instruction to change the contents of the print processing settings, etc. can be notified in a timely manner, and a user's erroneous operation or in-tray sensors (VR) 182, 183a, It is possible to prevent malfunction due to deterioration of 183b.

  Furthermore, in this embodiment, when it is determined that the detection results of the in-tray sensors (VR) 182, 183a, 183b and the conveyance paper width sensor (CIS) 184 are different, the detection result by the conveyance paper width sensor (CIS) 184. Therefore, even if the in-tray sensors (VR) 182, 183a, 183b are deteriorated to correct the table data of the in-tray sensors (VR) 182, 183a, 183b, the conveyance sheet width sensor (CIS) By correcting using the detection result by 184, the detection value by the deteriorated VR can be made appropriate, and the paper width detection accuracy can be prevented from being lowered. The use of the device can be continued.

  Further, in this embodiment, when it is determined that the comparison value between VR and CIS is large, the printing process is changed, so that the deterioration of one detection unit is complemented by the other detection unit, and the printing operation is performed. Can be continued.

  Furthermore, in this embodiment, even when it is determined that the in-tray sensors (VR) 182, 183a, and 183b are deteriorated, at least the first sheet is conveyed at a low speed based on a user operation. Since the printing process is continued only based on the detection result of the transport paper width sensor (CIS) 184 without using the detection results of the in-tray sensors (VR) 182, 183a and 183b, the erroneously detected value is ignored. The processing can be continued while. At this time, the detection accuracy is reduced because only the detection value by the other detection means is used, but the total accuracy can be kept constant by reducing the conveyance speed accordingly.

CR: Normal transport path FR: Paper feed system transport path R: Registration unit SR ... Switchback path 100 ... Printing device 110 ... Head unit 120, 130 ... Paper feed tray 121a, 121b ... Side fence 130 ... Paper feed tray 140 ... Discharge Paper outlet 150... Discharge tray 160... Conveying belt 161... Driving roller 162... Driven rollers 170 and 172.
184 ... Conveyance paper width sensor (CIS)
220 ... Side paper feed drive unit 230a, 230b ... Tray drive unit 240 ... Registration drive unit 250 ... Belt drive unit 260 ... First upper surface transport drive unit 265 ... Second upper surface transport drive unit 270 ... Upper surface discharge drive unit 280 ... Switchback Path driving unit 290 ... Driving roller 330 ... Arithmetic processing unit 330a ... Operation panel 331 ... Print control unit 331a ... Image formation control unit 331b ... Color conversion circuit 332 ... Sensor monitoring unit 332a ... Sliding counting unit 332b ... Comparison unit 332c ... Mode Setting unit 332d ... correction unit 332e ... notification unit 333 ... image data reception unit 334 ... conveyance path drive control unit 335 ... scheduling unit

Claims (9)

A printing apparatus that detects a width of a sheet to be supplied from a sheet feeding unit to a conveyance path, forms an image on the conveyance path based on the detected sheet width, and performs a printing process.
First paper width detecting means for detecting the width of paper fed by the paper feeding means;
Second paper width detection means for detecting the width of the paper conveyed along the conveyance path;
Comparison means for comparing the detection result by the first paper width detection means with the detection result by the second paper width detection means;
With
The first paper width detection means is slid in the paper width direction and detects the paper width based on an electrical resistance value with a separation distance according to the paper width,
The printing apparatus according to claim 2, wherein the second paper width detecting means receives a reflection of light applied to the paper and detects the paper width based on the received reflected light. The first paper width detecting means has a pair of measuring electrodes for measuring a separation distance according to the paper width by an electric resistance value,
2. The comparison means according to claim 1, further comprising a sliding counting means for counting the number of times the measuring electrode slides, and calculating the comparison result according to a counting result obtained by the sliding counting means. The printing apparatus as described.   The sliding counting means divides a sliding range of the measuring electrode based on a paper width corresponding to the size of the paper, and counts a sliding frequency for each of the divided sections. The printing apparatus according to claim 2. The sliding counting means counts the number of times the measuring electrode slides according to the change in the electrical resistance value while the measuring electrode is energized,
When the energization to the measurement electrode is cut off, the position of the measurement electrode immediately before cutting is stored, and the stored position and the position of the measurement electrode when the energization is resumed are stored. 3. The printing apparatus according to claim 2, wherein when the position is changed, a predetermined number of times is added to the number of sliding times.   The printing apparatus according to claim 1, further comprising a notifying unit that notifies a comparison result by the comparing unit.   When it is determined by the comparison means that the detection result by the first paper width detection means is different from the detection result by the second paper width detection means, based on the detection result by the second paper width detection means. The printing apparatus according to claim 1, further comprising a correction unit that corrects a detection result of the first paper width detection unit.   When it is determined by the comparison means that the detection result by the first paper width detection means is different from the detection result by the second paper width detection means, the at least first sheet is detected based on a user operation. 3. The printing apparatus according to claim 1, further comprising a print control unit that performs conveyance at a low speed and executes the printing process based only on a detection result of the second sheet width detection unit. The transport path forms a circulation path, and image formation can be performed a plurality of times.
When it is determined by the comparison means that the detection result by the first paper width detection means is different from the detection result by the second paper width detection means, the at least first sheet is detected based on a user operation. The printing apparatus according to claim 1, further comprising a print control unit that circulates the conveyance and executes the printing process based only on a detection result of the second paper width detection unit. A print control method for detecting a width of a sheet to be supplied from a sheet feeding unit to a conveyance path and forming an image on the conveyance path based on the detected sheet width to perform a printing process.
A sheet width detecting step of detecting a width of a sheet fed by the sheet feeding unit by a first sheet width detecting unit and detecting a width of the sheet conveyed by the second sheet width detecting unit. When,
A comparison step for comparing the detection result by the first paper width detection means with the detection result by the second paper width detection means;
In the paper width detection step,
The first paper width detection means is slid in the paper width direction and detects the paper width based on an electrical resistance value with a separation distance according to the paper width,
The print control method according to claim 2, wherein the second paper width detecting means receives a reflection of light irradiated on the paper and detects the paper width based on the received reflected light.