JP2006133571A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the image forming quality corresponding to the type of transfer paper, without spoiling the image forming speed as far as possible, to improve reliability of setting for image forming process conditions, corresponding to the paper type and furthermore to save time and labor to cope with the situation, when an image forming sequence is stopped due to mismatching of the paper type. <P>SOLUTION: The image forming apparatus is provided with an image forming means, a paper feed means which feeds paper to the image forming means from a paper feed stage 103a and ejects the paper with the image formed on it, a paper type discriminating means which discriminates the paper type classified by paper thickness or light transmission amount, a resistor BRap/MRap which retains the paper-type data for the paper in the paper feeding stage 103a and an image formation control means 131, which sets the image forming process conditions corresponding to the paper type data of the resistor and stops the feeding out of the paper to the image forming means, when the discriminated paper type of the paper fed out to the image forming means for forming the image under the image forming conditions is not coincident with the paper type data in resistor BRap/MRap. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus that forms an image on a sheet, and in particular, although not intended to be limited to this, forms a color image by superimposing and transferring each color toner image on an intermediate transfer belt, and transferring the image onto a sheet. The present invention relates to an intermediate transfer type color image forming apparatus. This image forming apparatus can be used in, for example, a copying machine, a printer, and a facsimile machine.

  Conventionally, as for a sheet for forming an image used in an image forming apparatus such as a copying machine, a laser beam printer, and a facsimile machine, that is, a transfer sheet, a transfer sheet recommended by each apparatus is almost determined. This is because, in a copying machine or the like, when an image is formed on transfer paper such as paper, the weight of the transfer paper, that is, the thickness of the transfer paper whose correlation with the weight is known, determines the image quality. This is because it is a very large factor. In particular, in a color copying machine that forms an image by superimposing four color toners (developers) on one sheet of transfer paper, the amount of toner placed on the transfer sheet is considerably larger than that of a black-and-white copying machine. Therefore, the difference in the thickness of the transfer paper greatly affects the image quality. For example, in a general heating type fixing device that melts and fixes toner, the thicker the transfer paper is, the more heat is taken away by the transfer paper at the time of fixing. Less heat is provided. For this reason, in a color image having a large amount of toner, the toner is not sufficiently melted and tends to cause a fixing failure.

  In order to prevent such a fixing failure, a color copying machine is required to have a particularly severe fixing temperature management corresponding to the thickness of the transfer paper as compared with a monochrome copying machine.

JP-A-9-34310 Japanese Patent Laid-Open No. 11-161042 In Japanese Patent Laid-Open No. 2000-75562, the displacement amount of the registration roller due to paper passing (paper biting) is detected to measure the thickness of the transfer paper, and the transfer bias and fixing temperature corresponding to the thickness. An image forming apparatus that changes image forming parameters is also described. In Patent Document 2, the transmission light amount of the transfer paper is detected by transmission type optical sensors 51 and 52 arranged in front of the registration roller 37, and the reflection light amount of the transfer paper surface is detected by reflection type optical sensors 51 and 53. In addition, an image forming apparatus is described in which the transparency, thickness, color, and the like of transfer paper are identified from the transmitted light amount and the reflected light amount, and the transfer voltage and the like are determined in accordance with these. In Patent Document 3, the light emitted from the light emitting element 120 and transmitted through the transfer paper in the transfer paper path is received by the light receiving element 121 and the amount of light transmitted through the transfer paper is measured. An image forming apparatus that determines the sheet passing speed is described.

  As described above, there is an image forming process control that detects the paper type classified by the paper thickness of the transfer paper or the amount of transmitted light and sets the image forming process conditions such as transfer bias and fixing conditions corresponding thereto. If the speed is high, setting of image forming process conditions based on the detection of the paper type at the position of the registration roller (for example, changing the fixing temperature and the paper passing speed) may not be in time. Therefore, the paper type of the transfer paper in the paper feed stage is held in the register, the image forming process conditions corresponding to this are set, paper feeding is started, and when the transfer paper reaches the registration roller section, the paper type is detected. The paper type held in the register is collated, and if it matches, the image forming sequence is continued, and if it is different, the image forming sequence is stopped.

  However, when the paper feed path from the paper feed stage to the registration roller is long, the number of prints specified is large, and when one of the transfer paper arrives at the registration roller, it is already fed out from one or more subsequent paper feed trays. In this printing mode, the detected paper type at the registration roller unit does not match the preset image forming process conditions, and if the image forming sequence is stopped there, it is necessary to discharge a plurality of transfer papers. Immediately after the power is turned on, there is a possibility that different types of transfer paper have been replaced or replenished in the paper feed stage, and even while the power is on, the different types of transfer paper have been replaced by taking out the paper feed tray. Or it may be replenished. In such a case, time and labor are wasted by stopping the above-described image forming sequence.

  The first object of the present invention is to improve the image forming quality corresponding to the paper type, and the second object is to increase the reliability of setting the image forming process condition corresponding to the transfer paper type. A third object is to reduce the handling time and labor when the image forming sequence is stopped due to the mismatch between the paper type and the image forming process condition. A fourth object is to realize these without losing the image forming speed (number of images formed / time) as much as possible.

(1) Image forming means (102-120) for forming a visible image on paper;
Paper feeding means (105, 107) for feeding paper from the paper feed stage (103a) to the image forming means and discharging the paper on which the image forming means has formed an image;
A paper type discriminating means (50, 54, 131, 136) for discriminating a paper type of the paper fed by the paper feeding means to the image forming means, which is classified by the paper thickness or transmitted light amount;
A register (BRap / MRap) for holding paper type data of the paper in the paper feed stage (103a); and
The image forming process condition corresponding to the paper type data of the register is set in the image forming means (19a / 19b), and the paper type discrimination of the paper sent to the image forming means for image formation under the image forming process condition When the paper type determined by the means (50, 54, 131, 136) does not match the paper type data of the register (BRap / MRap), the paper feeding to the image forming means is stopped (12a / 12b-14-15 / 21) Image control means (131);
An image forming apparatus comprising:

  In addition, in order to make an understanding easy, the code | symbol of the corresponding element or the corresponding matter of the Example shown in drawing and mentioned later is added for reference to the inside of a parenthesis. The same applies to the following.

  Since the paper type data of the paper in the paper feed stage (103a) is held in the register (BRap / MRap) and the image forming process conditions corresponding to the paper type data are set in the image forming means, the image forming process starts early. be able to. It is conceivable that the paper type of the paper that is actually fed differs from the paper type data held in the register (BRap / MRap) by exchanging or replenishing the transfer paper in the paper feed stage. At this time, since the feeding of the paper to the image forming means is stopped, low quality image formation due to paper type mismatch is prevented in advance.

  (2) The register (BRap / MRap) includes an operator-specified paper type register (BRap) for holding paper type data specified by the operator (PMDa, PMDb, 5-14, 12a-14); ). When the paper type changes due to replacement or replenishment of the transfer paper in the paper feed stage, the operator updates the paper type data in the register (BRap) to that of the new paper type loaded in the paper feed stage. There is no stoppage of paper feeding due to misalignment. However, if the paper type data in the register (BRap) is not updated in accordance with the change in the paper type of the paper feed stage, the paper feed stop due to the paper type mismatch occurs. At this time, the operator may update the paper type data in the register (BRap) with the paper type data that matches the paper type of the paper feed stage.

  (3) The register (BRap / MRap) includes a determination result paper type register (MRap) that holds the paper type determined by the paper type determination means (50, 54, 131, 136) (PMDb, 12b-14) The image forming apparatus according to (1) or (2) above. When the paper type changes due to replacement or replenishment of the transfer paper in the paper feed stage, the paper feed stop occurs due to paper type mismatch. In this case, the paper type discriminating means (50, 54, 131, 136) is updated to the paper type data in the paper type register (MRap) of the discrimination result to the paper type discriminated, thereby stopping the paper feeding due to the paper type mismatch. Will not occur.

(3a) Image forming means (102-120) for forming a visible image on paper;
Paper feeding means (105, 107) for feeding paper from the paper feed stage (103a) to the image forming means and discharging the paper on which the image forming means has formed an image;
A paper type discriminating means (50, 54, 131, 136) for discriminating a paper type of the paper fed by the paper feeding means to the image forming means, which is classified by the paper thickness or transmitted light amount;
Operator-specified paper type register (BRap) that holds the paper type data specified by the operator;
A paper type register (MRap) of a discrimination result for holding the paper type discriminated by the paper type discriminating means (50, 54, 131, 136); and
The paper type data determined by the paper type determination means (50, 54, 131, 136) of the paper sent to the image forming means does not match the paper type data of the paper type register (MRap) of the determination result, but the paper specified by the operator When it matches the type register (BRap), the paper type data in the paper type register (MRap) of the discrimination result is updated to the paper type data discriminated by the paper type discriminating means (50, 54, 131, 136) (3 in FIG. 12). To 6), the image forming process condition corresponding to the paper type data of the paper type register (MRap) of the discrimination result is set in the image forming means (19b), the image forming control means (131);
An image forming apparatus comprising:

  According to this, when the paper type changes due to replacement or replenishment of the transfer paper in the paper feed stage, the operator updates the paper type data in the register (BRap) to that of the paper type newly loaded in the paper feed stage. Therefore, even if the paper type determined by the paper type determining means (50, 54, 131, 136) does not match the paper type data in the paper type register (MRap) of the determination result, the paper feed stop due to the paper type mismatch is stopped. The paper type data in the paper type register (MRap) of the discrimination result is automatically updated to the paper type data discriminated by the paper type discriminating means (50, 54, 131, 136). However, when the operator does not update the paper type data in the register (BRap) in accordance with the change in the paper type of the paper feed stage, the paper feed stop due to the paper type mismatch occurs. At this time, the operator may update the paper type data in the register (BRap) with the paper type data that matches the paper type of the paper feed stage.

  (3b) The image forming control means should set an image forming process condition corresponding to the paper type data in the paper type register (MRap) of the determination result in the image forming means and perform image formation under the image forming process condition. When the paper type data discriminated by the paper type discriminating means (50, 54, 131, 136) of the paper to be sent to the image forming means does not match the paper type data of the paper type register (MRap) of the discrimination result, the image forming means. The image forming apparatus according to (3a), wherein the sheet feeding is stopped (PMDb-12b-14-15). According to this, when different kinds of paper are mixed in the paper feed stage or when different kinds of paper are added, the feeding of the different kinds of paper is stopped. Unintentional non-standard paper is prevented from being sent to the image forming stage.

  (4) In response to the start instruction, the image forming means (131) refers to information on whether or not paper has been fed immediately after the paper loading operation to the paper feed stage, and If the sheet is being fed, the first sheet is fed out from the sheet feeding stage, and the second sheet is suspended until the sheet type is discriminated by the sheet type discriminating means (50, 54, 131, 136). (2-11) The image forming apparatus according to any one of (1) to (3b) above.

  Immediately after a paper loading operation is performed on the paper feed stage, there is a possibility that a paper of a paper type different from the paper type data in the register is loaded in the paper feed stage. In this case, if one or a plurality of subsequent sheets are fed out after the printing is started in response to a continuous printing instruction for a plurality of sheets and the paper type determination of the first sheet is completed. When paper feeding is stopped according to the paper type discrimination result, a plurality of papers must be removed from the apparatus. However, in this embodiment, immediately after a paper loading operation is performed on the paper feed stage, only one sheet is fed, the paper type discrimination is completed, and if the paper type has not changed, the second The paper after the first sheet is fed out. Therefore, it is easy to remove the feeding stop sheet from the inside of the machine when the paper type does not match.

  (5) Immediately after the power is turned on, the image forming means (131) sends out the first sheet from the paper feed stage in response to a start instruction, and the paper type discrimination means (50, 54, 131. The image forming apparatus according to any one of (1) to (4), in which the second sheet is suspended (1-3 to 11) until the determination by (131, 136) is completed.

  Immediately after the power is turned on, there may be a paper loading operation for the paper feed stage while the power is off. In this case, if one or a plurality of subsequent sheets are fed out after the printing is started in response to a continuous printing instruction for a plurality of sheets and the paper type determination of the first sheet is completed. When paper feeding is stopped according to the paper type discrimination result, a plurality of papers must be removed from the apparatus. However, in this embodiment, immediately after the power is turned on, only one sheet is fed and the sheet type discrimination is completed. If the sheet type has not changed, the second and subsequent sheets are fed out. Therefore, it is easy to remove the feeding stop sheet from the inside of the machine when the paper type does not match.

  (6) The image forming means (131) has the paper type discriminated by the paper type discriminating means (50, 54, 131, 136) of the paper sent to the image forming means inconsistent with the paper type data of the register (BRap / MRap) In this case, the image forming apparatus according to any one of (1) to (5), wherein the feeding of the sheet to the image forming unit is stopped, the image forming is stopped, and the sheet is only discharged and conveyed. According to this, the paper remaining on the in-machine conveyance path without image formation together with the image-formed paper is automatically discharged.

  (6a) The image forming apparatus according to (6), wherein the image forming unit (131) notifies a paper type error when the image forming is stopped and only the paper is discharged and conveyed. By the paper type error notification, the operator can easily recognize the occurrence of the paper type error.

  (7) In the image forming means (131), the paper type determined by the paper type determining means (50, 54, 131, 136) of the paper sent to the image forming means does not match the paper type data in the register (BRap / MRap) In this case, the image forming apparatus according to any one of (1) to (5), wherein image formation is stopped and conveyance of the sheet is stopped. According to this, a paper jam stop state in which both the imaged paper and the paper of paper type inconsistent remain in the apparatus. In this case, the paper type mismatched feeding paper does not pass through the image forming stage, so that the image forming stage is not damaged or deteriorated by excessive passage of non-standard paper type paper.

  (7a) The image forming apparatus according to (7), wherein the image forming unit (131) notifies paper jam when the image forming is stopped and the conveyance of the paper is stopped. The paper jam notification allows the operator to easily recognize paper troubles.

  (8) The image forming means (102-120) is an intermediate transfer type color image forming apparatus that forms a color image by superimposing and transferring a plurality of color toner images to the intermediate transfer means (106), and transferring the color image onto a sheet. The image forming apparatus according to any one of (1) to (7a).

  (9) The paper type discriminating means (50, 54, 131, 136) includes a light emitting element (LED), a light receiving element (PTr) that receives the light projected in the direction across the gap through which the light emitting element passes through the gap and then passes through the gap. ), Means (55) for generating an electric signal (Vpd) corresponding to the light receiving level of the light receiving element, and means (44, 45, 131) for encoding the electric signal into paper type data. The image forming apparatus according to any one of (1) to (8), including a measurement device.

  (10) The image forming apparatus according to (9), further including range setting means (56, 57, 131) for switching the range of the electric signal (Vpd).

  (11) The image forming apparatus according to (10), wherein the range setting unit determines whether or not range switching is necessary by using a threshold value (Vt1) referred to for encoding the electrical signal into paper type data.

  Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

  FIG. 1 shows the appearance of a multi-function full-color digital copying machine according to an embodiment of the present invention. This full-color copying machine is roughly constituted by units of an automatic document feeder (ADF) 30, an operation board 20, a color scanner 10, a color printer 100, and a paper feed bank 35. A LAN (Local Area Network) connected to the personal computer PC11 is connected to the system controller 1 (FIG. 3) in the machine. The facsimile controller FCU (FIG. 3) in the machine can perform facsimile communication via the exchange PBX and the public communication network PN.

  FIG. 2 shows an outline of the mechanism unit of the copying machine shown in FIG. The printer 100 of the copying machine includes an intermediate transfer unit at the center, and the intermediate transfer unit includes an intermediate transfer belt 106 that is an endless belt. The intermediate transfer belt 106 is a multi-layer belt in which an elastic layer is provided on a base layer made of a material that hardly stretches, such as a fluorine resin with a small elongation or a rubber material with a large elongation and a canvas. The elastic layer is formed, for example, by coating a fluorine-based resin or the like on the surface of fluorine-based rubber or acrylonitrile-butadiene copolymer rubber to form a smooth coat layer.

  The intermediate transfer belt 106 is wound around three support rollers and is driven to rotate clockwise. An intermediate transfer member cleaning unit for removing residual toner remaining on the intermediate transfer belt 106 after image transfer is provided near one support roller.

  The intermediate transfer belt 106 between one support roller and another support roller has black (K), yellow (Y), cyan (C), and magenta (M) colors along the moving direction. The image forming apparatus is composed of a photosensitive unit 11K, Y, C, M, a charger unit, a developing unit 120K, Y, C, M and a cleaning unit 110K, Y, C, M, and each unit is individually provided. The printer body is detachably mounted.

  Above the image forming apparatus, there is a laser exposure unit 102 that irradiates each photosensitive drum of each color photosensitive unit with laser light for image formation.

  Below the intermediate transfer belt 106 is a conveyance belt 107. The conveyor belt 107 transfers the image on the intermediate transfer belt 106 onto a sheet. The sheet on which the image is transferred (transfer sheet) is sent out to the fixing unit 108 by the conveyor belt 107. The fixing unit 108 is a unit in which a heating and pressure roller is pressed against a fixing belt which is an endless belt. Below the conveying belt 107 and the fixing unit 108, there is a double-sided drive unit 33 which is a sheet reversing unit that feeds a sheet immediately after an image is formed on the front surface and reverses the front and back to record an image on the back surface.

  When the start switch is pressed, if there is a document on the automatic document feeder (ADF) 30, it is transported onto the contact glass of the scanner 10, and if there is no document on the ADF, the manually placed document on the contact glass Immediately, the scanner 10 is driven, and the first carriage and the second carriage in the scanner 10 are read and scanned. Then, light is emitted from the light source on the first carriage to the contact glass, and reflected light from the document surface is reflected by the first mirror on the first carriage and directed to the second carriage, and reflected by the mirror on the second carriage. Then, an image is formed on a CCD as a reading sensor through an imaging lens. K, Y, M, and C color recording data are generated based on the image signal obtained by the reading sensor.

  Further, when the start switch is pressed, the rotational drive of the intermediate transfer belt 106 is started, the image forming preparation of each unit of the image forming apparatus is started, and the image forming sequence of each color image forming is started. Then, an exposure laser modulated based on each color recording data is projected onto the photosensitive drum for each color, and each color toner image is superimposed and transferred as a single image on the intermediate transfer belt 106 by each color image forming process. The When the leading edge of the toner image enters the conveyance belt 107, the sheet is fed from the registration roller 105 to the transfer belt 107 at a timing so that the leading edge enters the conveyance belt 107. The toner image is transferred to the paper. The sheet on which the toner image has moved is sent to the fixing unit 108 where the toner image is fixed on the sheet.

  Note that the above-described sheet is selectively rotated by driving one of the sheet feeding rollers immediately above the sheet feeding trays (also referred to as sheet feeding stages or cassettes) 103 a to 103 d of the sheet feeding bank 35, so that the sheet feeding bank 35 has multiple stages. The sheet is fed out from one of the paper feed trays 103a to 103d, separated by one by a separation roller, put into a vertically arranged transport roller unit, transported upward, and guided to the transport roller unit in the printer 100 for transport. After abutting and stopping on the registration roller 105 of the roller unit, the roller is sent to the conveyor belt 107 at the timing described above. It is also possible to feed paper by inserting paper on the right side manual feed tray. When the user is inserting paper onto the manual feed tray, the printer 100 rotates the paper feed roller of the manual feed tray to separate one sheet on the manual feed tray and pull it into the manual feed path. Stop at 105.

  The sheet discharged after receiving the fixing process by the fixing unit 108 is guided to the discharge roller by the switching claw and stacked on the discharge tray 109. Alternatively, it is guided to the double-sided drive unit 33 by the switching claw, reversed there and led again to the transfer position, and after the image is recorded also on the back surface, it is discharged onto the discharge tray 109 by the discharge roller.

  On the other hand, the residual toner remaining on the intermediate transfer belt 106 after image transfer is removed by an intermediate transfer member cleaning unit (not shown) to prepare for image formation again.

  A voltage of about −800 V is applied to the intermediate transfer belt 106 on the toner transfer side (front side), and a voltage of about +200 V is applied to the back side of the paper. Generally, in the intermediate transfer system, paper dust is difficult to move to the photoconductor, so that it is not necessary to consider paper dust transfer and may be grounded. Further, a DC bias is applied as the applied voltage, but this may be an AC voltage having a DC offset component in order to more uniformly charge the sheet.

  During continuous copying or printing, a plurality of toner images are sequentially transferred from the intermediate transfer belt 106 at different locations. That is, the intermediate transfer belt 106 can carry a plurality of toner images simultaneously. In full-color recording, each toner image is an overlap of four-color toner images. Accordingly, if the image forming process conditions such as the transfer condition and the fixing condition are different from the actually fed paper type (transfer paper type), many defective copies or printings are performed. there is a possibility. In order to prevent this, the light projection circuit board 50 and the light receiving circuit board 54 for detecting the paper type are installed at the position of the registration roller 105, and the process controller 131 (FIG. 3) is abutted against the registration roller 105. The amount of light transmitted through the sheet (transfer sheet) is detected to determine the sheet type. When a sheet type different from the sheet type to which the set image forming process condition is addressed is detected, the image forming process is stopped there. Paper type detection by the light projecting circuit board 50, the light receiving circuit board 54, and the process controller 131 will be described later with reference to FIG.

  FIG. 3 shows a system configuration of the image processing system of the copying machine shown in FIG. In this system, a color document scanner 10 including a reading unit 11 and an image data output I / F (Interface) 12 is connected to an image data interface control CDIC (hereinafter simply referred to as CDIC) of an image data processing apparatus ACP. Yes. A color printer 100 is also connected to the image data processing apparatus ACP. The color printer 100 receives the recorded image data from the image data processor IPP (Image Processing Processor; hereinafter simply referred to as IPP) of the image data processing apparatus ACP to the writing I / F 134 and prints it out by the image forming unit 135. . The image forming unit 135 is shown in FIG.

  The image data processing device ACP (hereinafter simply referred to as ACP) includes a parallel bus Pb, a memory access control IMAC (hereinafter simply referred to as IMAC), a memory module that is an image memory (hereinafter simply referred to as MEM), and a nonvolatile memory. A hard disk device HDD (hereinafter simply referred to as HDD), system controller 1, RAM 4, nonvolatile memory 5, font ROM 6, CDIC, IPP, and the like are provided. A facsimile control unit FCU (hereinafter simply referred to as FCU) is connected to the parallel bus Pb. The operation board 20 is connected to the system controller 1.

  The reading unit 11 for optically reading the original of the color original scanner 10 photoelectrically converts the reflected light of the lamp irradiation on the original with a CCD on a sensor board unit SBU (hereinafter simply referred to as SBU). , B image signals are generated, converted to RGB image data by an A / D converter, shading corrected, and sent to the CDIC via the output I / F 12. The RGB image data is multi-value image data (for example, 8-bit configuration) representing multi-gradation having a configuration of 3 bits or more.

  The CDIC performs data transfer between the document scanner 10 (output I / F 12), the parallel bus Pb, and the IPP and communication between the process controller 131 and the system controller 1 that controls the ACP. The NVRAM 132 is used as a work area for the process controller 131, and the ROM 133 stores an operation program for the process controller 131.

  Memory access control IMAC (hereinafter simply referred to as IMAC) controls writing / reading of image data and control data to / from MEM and HDD. The system controller 1 controls the operation of each component connected to the parallel bus Pb. The RAM 4 is used as a work area for the system controller 1, and the nonvolatile memory 5 stores an operation program for the system controller 1.

  The operation board 20 instructs processing to be performed by the ACP. For example, the type of processing (copying, facsimile transmission, image reading, printing, etc.), the number of processings, etc. are input. Thereby, the image data control information can be input.

  The image data read from the reading unit 11 of the scanner 10 is subjected to shading correction by the SBU of the scanner 10 and then subjected to image processing for correcting reading distortion such as background removal, scanner gamma correction, and filter processing by the IPP. To MEM or HDD. When printing out MEM or HDD image data, IPP performs color conversion of RGB signals to YMCK signals, and performs image quality processing such as printer gamma conversion, gradation conversion, and gradation processing such as dither processing or error diffusion processing. Do it. The image data after the image quality processing is transferred from the IPP to the writing I / F 134. The writing I / F 134 performs laser control on the gradation processed signal by pulse width and power modulation. Thereafter, the image data is sent to the image forming unit 135, and the image forming unit 135 forms a reproduced image on the transfer paper.

  Based on the control of the system controller 1, IMAC controls the access of image data and MEM or HDD, develops data for printing on a personal computer PC1 (hereinafter simply referred to as PC) connected to the LAN, and effectively uses MEM and HDD. Compress / decompress image data for

  The image data sent to the IMAC is stored in the MEM or HDD after data compression, and the stored image data is read out as necessary. The read image data is decompressed, returned to the original image data, and returned from the IMAC to the CDIC via the parallel bus Pb. After the transfer from the CDIC to the IPP, image quality processing is performed and the image is output to the writing I / F 134, and a reproduced image is formed on the transfer paper in the image forming unit 135.

  In the flow of image data, the functions of the digital multi-function peripheral are realized by the bus control by the parallel bus Pb and the CDIC. Facsimile transmission is performed by performing image processing on the read image data by IPP and transferring it to the FCU via the CDIC and the parallel bus Pb. The FCU performs data conversion to the communication network and transmits it as facsimile data to the public line PN. Facsimile reception is performed by converting line data from the public line PN into image data by the FCU and transferring it to the IPP via the parallel bus Pb and CDIC. In this case, no special image quality processing is performed, and the image is output from the writing I / F 134 and a reproduced image is formed on the transfer paper in the image forming unit 135.

  In a situation where a plurality of jobs, for example, a copy function, a facsimile transmission / reception function, and a printer output function operate in parallel, the usage rights of the reading unit 11, the image forming unit 135, and the parallel bus Pb are allocated to the system controller 1 and the process. Control is performed by the controller 131. The process controller 131 controls the flow of image data, and the system controller 1 controls the entire system and manages the activation of each resource. The function selection of the digital multi-function peripheral is performed on the operation board 20, and processing contents such as a copy function and a facsimile function are set by a selection input of the operation board 20.

  The system controller 1 and the process controller 131 communicate with each other via the parallel bus Pb, CDIC, and serial bus Sb. Specifically, communication between the system controller 1 and the process controller 131 is performed by performing data format conversion for data and interface between the parallel bus Pb and the serial bus Sb in the CDIC.

  Various bus interfaces, such as a parallel bus I / F 7, a serial bus I / F 9, a local bus I / F 3, and a network I / F 8, are connected to the IMAC. The controller unit 1 is connected to related units via a plurality of types of buses in order to maintain independence in the entire ACP.

  The system controller 1 controls other functional units via the parallel bus Pb. The parallel bus Pb is used for transferring image data. The system controller 1 issues an operation control command for storing image data in the MEM and HDD to the IMAC. This operation control command is sent via IMAC, parallel bus I / F 7, and parallel bus Pb.

  In response to this operation control command, the image data is sent from the CDIC to the IMAC via the parallel bus Pb and the parallel bus I / F 7. The image data is stored in the MEM or HDD under the control of the IMAC.

  On the other hand, the ACP system controller 1 functions as a printer controller, network control, and serial bus control in the case of a call from the PC as a printer function. In the case of via the network B, the IMAC receives print output request data or storage (storage) request data via the network B via the network I / F 8. Request data (foreign command) via the network B is notified to the system controller 1, and the IMAC transfers or receives and accumulates the accumulated data via the network B in accordance with a command from the system controller 1 that responds to the request data.

  Print output request data from the personal computer PC1 is developed into image data by the system controller 1. The development destination is an area in MEM. Font data necessary for expansion is obtained by referring to the font ROM 6 via the local bus I / F 3 and the local bus Rb. The local bus Rb connects the controller 1 to the nonvolatile memory 5 and the RAM 4. Regarding the serial bus Sb, in addition to the external serial port 2 for connection to the PC 1, there is also an interface for transfer with the operation board 20 which is an ACP operation unit. This is not print development data, but communicates with the system controller 1 via the IMAC, accepts processing procedures, displays the system status, and the like. Data transmission / reception between the system controller 1 and the MEM, HDD, and various buses is performed via the IMAC. Jobs that use MEM and HDD are centrally managed in the entire ACP.

  The process controller 131 controls the driving elements of the image forming mechanism of the image forming unit 135 (FIG. 2) on and off via the interface 136, and also reads the detection signals of various sensors (sensor units 137) of each unit. The state of the image unit 135 is determined, and the operation of the image forming unit 135 and the image forming process conditions are controlled. That is, the image forming process is controlled. The sensor unit 137 includes the light projecting circuit board 50 and the light receiving circuit board 54 shown in FIG. 2, and the interface 136 includes a detection signal processing circuit connected to the electric circuits of the light projecting circuit board 50 and the light receiving circuit board 54. It is.

  FIG. 4 shows a system for discriminating the type of paper (transfer paper) using the light projecting circuit board 50 and the light receiving circuit board 54. The light emitting circuit board 50 includes a light emitting diode LED, and a cathode thereof is connected to an equipment ground through a current value detection resistor 51. A variable current limiting resistor 53 and a current value control transistor 52 are interposed in series between the constant voltage power supply line Vcc and the anode of the light emitting diode LED. As the base bias of the transistor 52 increases, the amount of light emitted from the LED increases.

  A voltage (current value detection signal) proportional to the current value flowing through the LED appears in the detection resistor 51, and this voltage is applied to the negative phase (−) input terminal of the comparator 47. A threshold voltage for overcurrent determination is applied to the positive phase (+) input terminal of the comparator 47 from a voltage dividing circuit composed of resistors 47 and 48. When the value of the current flowing through the LED becomes equal to or greater than the current threshold corresponding to the threshold voltage, the binary output of the comparator 47 switches from the high level H to the low level L. This switching from H to L means occurrence of overcurrent. This binary output of the comparator 47 is applied to the input / output port i2. When the input signal of the input / output port i2 switches from H to L, the process controller 131 stops energizing the LED, displays an LED (light emitting circuit board 50) abnormality on the operation board 20, and performs the image forming process. Stop.

  The LED, the detection resistor 51, the variable current limiting resistor 53, and the transistor 52 described above are on the same light projecting circuit board 50, and are known to the transistor 52 before the board 50 is installed in the printer 100 as shown in FIG. The resistance value of the variable current limiting resistor 53 is adjusted so that the light emission amount of the LED becomes a known predetermined value when a predetermined bias voltage is applied. Therefore, it is not necessary to adjust the resistance value of the variable current limiting resistor 53 after the printer 100 is mounted. When any electric circuit element on the board 50 provided in the printer 100 fails or malfunctions, the board 50 is replaced with a new one. This not only facilitates the management of the sheet type discrimination, but also prevents a decrease in accuracy of the sheet type discrimination due to an operation error when individually adjusting or replacing the electric circuit elements of the substrate 50 provided in the printer 100. it can.

  The light receiving circuit board 54 has a phototransistor PTr that receives the projection light of the LED, and its emitter adjusts the voltage characteristics of the first switching transistor 57a and the light amount detection voltage / light reception amount of the first range, and the first variable load resistor. It is connected to the equipment ground through 55a. Alternatively, it is connected to the equipment ground through the second switching transistor 57b and the second variable load resistor 55b for adjusting the voltage characteristic of the light amount detection voltage / light reception amount of the second range. Alternatively, it is connected to the equipment ground through the third switching transistor 57c and the third variable load resistor 55c for adjusting the voltage characteristic of the light amount detection voltage / light reception amount of the third range.

  In the case of the first range reading setting in which the first transistor 57a is on and the second and third transistors 57b and 57c are off, the first variable that becomes a high voltage when there is a large amount corresponding to the amount of light received by the phototransistor PTr. The voltage (light quantity detection voltage Vpd) of the load resistor 55a increases (rises). This voltage Vpd is applied to an automatic light quantity controller (hereinafter referred to as APC) 43, and is adjusted (calibrated) to a level in the A / D conversion range with a constant amplification factor by an amplifier 44, and then the A / D converter 45. Given to. The first switching transistor 57a is turned on when the binary output of the first amplifier (switching driver) 46a is at the high level H. The binary output of the first amplifier 46a is controlled by the process controller 131 to H (first range designation) or L (second or third range designation) via the output port o1a of the input / output port 42.

  In the second range reading setting in which the second transistor 57b is on and the first and third transistors 57a and 57c are off, the voltage of the second variable load resistor 55b (corresponding to the amount of light received by the phototransistor PTr ( Vpd) changes to high and low. On / off of the second transistor 57b is controlled by the process controller 131 via the output port o1b of the input / output port 42 and the second amplifier 46b.

  In the third range reading setting in which the third transistor 57c is on and the first and second transistors 57a and 57b are off, the voltage of the third variable load resistor 55c (corresponding to the amount of light received by the phototransistor PTr ( Vpd) changes to high and low. On / off of the third transistor 57c is controlled by the process controller 131 via the output port o1c of the input / output port 42 and the third amplifier 46c.

  The phototransistor Ptr, the variable load resistors 55a to 55c, and the switching transistors 57a to 57c are on the same light receiving circuit board 54, and before the board 54 is mounted on the printer 100 as shown in FIG. The variable load resistor 55a is adjusted so that the detection voltage Vpd becomes a known predetermined value in the first range when an on-bias voltage is applied to the phototransistor PTr and a known predetermined amount of light is projected onto the phototransistor PTr, and only the switching transistor 57b When the on-bias voltage is applied to the phototransistor PTr and a known predetermined amount of light is projected onto the phototransistor PTr, the variable load resistor 55b is adjusted so that the detection voltage Vpd becomes a known predetermined value in the second range. Phototransistence by applying on-bias voltage In which the detection voltage Vpd has adjusting the variable load resistor 55c so that the known predetermined value of the third range when projecting a known predetermined amount to PTr. Therefore, it is not necessary to adjust the resistance values of the variable load resistors 55a to 55c after being mounted on the printer 100. When any electric circuit element on the board 54 equipped in the printer 100 fails or malfunctions, the board 54 is replaced with a new one. This not only facilitates the management of the sheet type discrimination, but also prevents a decrease in accuracy of the sheet type discrimination due to an operation error when individually adjusting or replacing the electric circuit elements of the board 54 provided in the printer 100. it can.

  The APC 43 includes a feedback circuit that internally generates a target value voltage Vm and adjusts the APC output (base bias of the transistor 52) so that the detection voltage Vpd during the first range setting matches the target value voltage Vm. In addition, when an off instruction signal is provided in response to an on / off instruction signal (LED lighting / light-out instruction signal) provided by the process controller 131 via the output port o3 of the input / output port 42, the transistor 52 is non-conductive (off). ) When a level voltage is output and an ON instruction signal is given, a conduction level voltage is output to the transistor 52. In addition, when the mode instruction signal (binary signal) given from the output port o4 is at the release instruction level when receiving the ON instruction signal from the output port o3, the detected voltage Vpd matches the target value voltage Vm. Feedback control for adjusting the APC output (base bias of the transistor 52) is executed. When the hold control level is switched, the feedback control is stopped and the APC output at that time is maintained (the APC output is fixed). The mode instruction signal (binary signal) is controlled by the process controller 131.

  When the process controller 131 reads the light amount detection signal Vpd, the process controller 131 gives an A / D conversion instruction signal from the output port o2 to the A / D converter 45 and outputs digital data (light amount detection data Vpd) output from the A / D converter 45. Read through input port i1.

  FIG. 5 shows the target voltage Vm and the threshold values Vt1 to Vt3 for paper type determination and the light amount detection voltage for each paper type (paper type, that is, transfer paper type). 5A shows the case where the first range is set, FIG. 5B shows the case where the second range is set, and FIG. 5C shows the case where the third range is set. The case where it is doing is shown. The target voltage Vm is a fixed value (analog voltage) generated inside the APC 43, but for the OHP (Over Head Projector paper; hereinafter simply referred to as OHP) determination in the first range and the range to the second range. The threshold value Vt1 for switching determination and the threshold values Vt2 and Vt3 for various determinations of the plain paper system in the third range are stored in the ROM 133, and are written in the nonvolatile memory NVRAM 132 at the time of power-on initialization. The “paper type detection” (PMDa) in FIG. 9 is read from the NVRAM 132 and used as described above, and both are fixed values. The threshold value Vt1 is used for determining the second original image in the second range and for determining the range switching to the third range, and further for determining the plain paper (45 kg) in the third range.

  Therefore, in the “paper type detection” (PMDA) in FIG. 9, it is easy to determine whether or not to switch from the first range to the second range and whether or not to switch from the second range to the third range. Since the threshold value need not be set or adjusted, the paper type discrimination process is simplified. However, the accuracy of the determination is high, and the paper type of the subdivision can be determined accurately and stably.

  Table 1 below summarizes the classification categories based on “paper type detection” (PMDA) shown in FIG.

  FIG. 6 shows an outline of “paper type data setting” (OPS) of the operation board 20 in response to an operator input. When the operator operates an initial setting key (not shown) of the operation board 20, the operation board 20 (the internal CPU) displays various initial setting items (initial setting menu) on the liquid crystal touch panel 79 of the operation board 20. When the operator designates the item “paper type setting” in the menu, the operation board 20 displays an input screen for paper type setting on the liquid crystal touch panel 79.

  FIG. 7 shows an input screen for setting the paper type. For example, when the OHP is stored in the paper feed stage 103a, the operator selects “tray 1”, specifies “OHP”, specifies “one-sided copy”, and “not applicable” on the input screen shown in FIG. And specify “Setting”.

  Reference is again made to FIG. When such an operator input is read, the operation board 20 updates the contents of the paper feed stage register addressed to the paper feed stage 103a in the operation board 20 to the information input by the operator (steps OP1 and OP2). The paper type “OHP” of the common expression (for input / output of the operation board) is converted into type category data (category No. in Table 1; “1” for OHP) used for process control, and information Is written in the paper type register BRap addressed to the paper feed stage 103a. That is, the information in the paper type register BRap of the operation board 20 is updated (OP3). In the same manner as described above, the paper type registers BRbp, BRcp, and BRdp addressed to the other paper feed stages 103b, c, and d also store the type classification data corresponding to the paper type of the common expression with the operator input. The

  In FIG. 8, the process controller 131 executes in response to a start input operation or a copy start instruction or a print start instruction (hereinafter simply referred to as a start instruction) from the system controller 1 in response to a print instruction from the personal computer PC1. An outline of image formation control using paper type detection is shown. Upon receipt of the start instruction, the process controller 131 refers to the data in the status register assigned to the NVRAM 132 which is a nonvolatile memory, and whether the current start instruction is the first start instruction after the power is turned on, or is designated as paper feed It is confirmed whether or not the paper feed tray (eg 103a) of the paper feed stage that has been placed is immediately after the take-out operation (paper loading operation) (the paper has not yet been fed after the take-in / out) (steps 1 and 2).

  In the following, the step is omitted and only the step symbol is written in parentheses.

  The process controller 131 clears the image formation execution register in the status register at the time of initialization immediately after the power is turned on, and writes image formation execution information in the image formation execution register when one or more image formation is executed. In the status register, the tray status register addressed to each of the paper feed trays 103a to 103d includes information indicating that the paper feed tray is being installed / separated and information from the paper feed tray after the paper tray is inserted and removed. The paper feed presence / absence information is held, and when a paper feed tray loading / unloading operation is detected, the paper feed presence / absence information is changed to no-paper feed information. In step 1 above, it is determined whether or not the current start instruction is the first start instruction after the power is turned on by referring to the presence or absence of image forming execution information in the image forming execution register. It is determined whether or not it is immediately after the loading / unloading operation with reference to the paper feed presence / absence information in the tray status register addressed to the tray.

  If this is the first start instruction after the power is turned on, the paper type in the paper feed tray has changed because the paper tray has been refilled or replaced during the previous power-off. There can be. Also, the paper type in the paper feed tray may change when the paper feed tray is inserted or removed while the power is on.

  In these cases, the controller 131 feeds one sheet from a sheet feed tray (for example, 103a) designated for sheet feeding (3) and executes “paper type detection” (PMDa). The contents thereof will be described later with reference to FIG. 9, but the paper type data (classification number data shown in Table 1) of the fed paper is generated.

  The paper type register BRip (BRap addressed to the paper feed stage 103a, BRbp addressed to the paper feed stage 103b, BRcp addressed to the paper feed stage 103c, BRdp addressed to the paper feed stage 103d) of the operation board 20 contains the paper specified by the operator. Paper type data representing the type (corresponding to the category No. data shown in Table 1) is held.

  When “paper type detection” (PMDa) is executed, the detected paper type data is collated with a paper type register BRip (BRap) addressed to a paper feed tray (for example, 103a) designated for paper feed (5). At the same time, the process controller 131 detects the image forming process conditions (mainly the development bias, the transfer voltage for transferring the toner image to the transfer belt 106, the transfer belt 106, and the transfer belt 107 corresponding to the detected paper type (= BRap paper type). The sheet adsorption voltage and the fixing target temperature to be applied are set (7), image formation on the one sheet is started (8), the number of image formations is incremented by 1 (9), and the specified number of sheets is reached. It is confirmed whether or not the number of image formation has been reached (10). When the specified number of images has been reached, the image formation control is terminated when the final image formation paper is discharged. When the designated number of sheets is a continuous copy of a plurality of originals or a plurality of originals using ADF, the next paper feed is started (11), and the process proceeds to the continuous printing control under the circle A.

  By the way, if the detected paper type of the first paper feed sheet does not match the paper type of the paper type register BRip (BRap) addressed to the paper feed tray (103a) designated for paper feed, “ A paper type error in the paper feed stage 103i (103a) "is notified (14), and the paper fed to the registration roller 105 is discharged (17).

  As described above, in the case of the first start instruction after the power is turned on, or in the case of the first paper feed instruction from the paper feed stage after the paper tray is put in and out, the designated number of copies or prints is 2. Even in the above case, when only the first sheet is fed to detect the paper type and the paper type matches the paper type held in the register BRip (BRap) of the operation board 20, the designated number of images ( If there is a discrepancy, a paper type error in the corresponding paper feed stage (103a) is notified (14), the image forming process is stopped, and the paper with the detected paper type is discharged without image formation. (15-17).

  This prevents conveyance of a paper type different from the operator-set paper type to the toner image transfer stage. In order to form an image on the different paper type, the operator may set the different paper type in the register BRip (BRap) of the operation board 20 by using the above-described “paper type data setting” (OPS). . However, since it is not possible to set a common paper type that is not indicated on the setting input screen (FIG. 7), an effect of preventing the use of paper types other than the paper type assigned to the copying machine (FIG. 7) can be expected.

  Next, when it is not the first start instruction after the power is turned on, nor is it the first paper feed instruction from the paper feed stage immediately after loading / unloading of the paper feed tray, that is, the register BRip (BRap) of the operation board 20 holds. If it can be estimated that the paper type of the paper in the paper feed stage 103i (103a) matches the paper type, the process controller 131 goes through steps 1 and 2 in FIG. The image forming process condition corresponding to the paper type held by the register BRip (BRap) addressed to the stage 103i (103a) is set as the image forming process condition of the image forming unit 135 (19a), and the specified number of images is started. (20). In this case, if the designated number of copies or prints is plural, the sheets are fed out sequentially from the designated paper feed stage in a predetermined sequence, the image forming speed (image forming number / time) is high, and depending on the image forming mode. In this case, the next and subsequent sheets are fed out from the sheet feeding tray before the leading edge of the first sheet hits the registration roller 105 and the sheet type is detected.

  However, in this embodiment, in order to detect the mixing of different paper types, the paper type is detected for each paper by “paper type detection” (PMDb). Then, the paper type detected by “paper type detection” (PMDb) is collated with the paper type held in the register BRip (BRap) addressed to the paper feed stage 103i (103a), and if both match, the image forming sequence is determined. Continuously, as long as the paper type of each feeding paper matches the paper type of the register BRip (BRap), image formation is continued up to the designated number (PMDb-12a-13-PMDb).

  However, if the paper type detected by “paper type detection” (PMDb) is different from the paper type held in the register BRip (BRap) addressed to the paper feed stage 103i (103a) (12a), the process controller 131 A “paper type error in the paper feed stage 103i (103a)” is notified via the operation board 20 (14), the paper feeding by the registration roller 105 is stopped, and the paper feeding from the paper feeding tray and the registration roller 105 are stopped. (15). Then, after all of the imaged paper has been taken out of the apparatus, the remaining paper (including the paper caught in the roller 105) that has been fed from the paper feed tray and up to the registration roller 105 is imaged. Instead, it is discharged onto the discharge tray 109 (16, 17). Then, the input to the operation board 20 is waited. When there is an input, the process returns from “image formation control” (PPCa) to input reading of the main routine (waiting for instruction). Note that “image formation control” (PPCa) shown in FIG. 8 is a subroutine that is executed when a “start instruction” is received during input reading.

  FIG. 9 shows the content of “paper type detection” (PMDa). The contents of “paper type detection” (PMDb) are the same as the contents of “paper type detection” (PMDa).

When the process proceeds to “paper type detection” (PMDa), the process controller 131 executes “light quantity adjustment” (31). FIG. 10 shows this content.
In the “light quantity adjustment” (31) shown in FIG. 10, first, the transistor 57a on instruction signal (H), the LED emission instruction signal (H), and the release instruction signal (H) are output to the output ports o1a, o3, and o4, respectively. (61). As a result, the switching transistor 57a is turned on, and the range of the detection voltage Vpd becomes the first range. Further, the APC 43 outputs a bias voltage at the energization level to the transistor 52, whereby the LED is lit, and the APC 43 The base bias voltage (output voltage of APC) of the transistor 52 is adjusted so that Vpd matches the target voltage Vm. That is, feedback control is performed. When this light amount adjustment is started, the controller 131 starts a timer with a Tw time limit (62) and waits for it to time out (64). This time limit value Tw is slightly longer than the time required for the detection voltage Vpd to substantially converge and stabilize at the target voltage Vm by the feedback control of the APC 43. If the input voltage of the input port i2 switches from H to L (overcurrent occurs in the LED line) while the timer of the Tw time expires, the controller 131 stops energizing the LEDs (63, 66). ), Sensor (50) error information is written into an error register defined in one area of the memory inside the controller 131 (67). After that, when the input port i2 switches from H to L while the LED is lit, the controller 131 stops energizing the LED, writes the sensor (50) error information to the error register, and detects the sensor error. This is displayed on the display of the operation board 20.

  When the Tw timer expires while the input voltage at the input port i2 remains H (sensor normal), the controller 131 switches the output at the output port o4 to the hold instruction (L) (65). As a result, the base bias of the transistor 52 is fixed (held) to a level that substantially matches the detection voltage Vpd with the target voltage Vm. Here, the controller 131 ends the “light amount adjustment” (31). At this time, the switching transistor 57a is on, and the light amount detection voltage Vpd is in the first range.

  Reference is again made to FIG. When the “light amount adjustment” (31) is completed, the controller 131 displays a sensor error on the operation board 20 (32, 50) when the sensor error is detected in the “light amount adjustment” (31), and feeds paper. Then, the light emission energization of the LED on the substrate 50 is stopped (51), and the process proceeds to step 15 of "image formation control" (PPCa) in FIG.

  When the “light quantity adjustment” (31) is finished, a sensor error is not detected, and a paper detector (registration sensor) (not shown) that detects the arrival of the leading edge of the paper at the registration roller 105 detects the arrival of the paper, that is, light emission. When the paper enters the optical path of the detection light between the LED as the element and the phototransistor PTr as the light receiving element (33), the controller 131 sends an A / D conversion instruction signal to the A / D converter 45 from the port o2. The light quantity detection data Vpd output and converted by the A / D converter 45 is compared with the threshold value Vt1 for determining the absence of paper in the first range (34). If Vpd is equal to or greater than the threshold value Vt1, the controller 131 stores in the paper type register PMR defined in one area of the internal memory, paper type data “1” indicating that the paper is OHP or special paper (Table 1). Reference) is written (35).

  However, if Vpd is less than the threshold value Vt1, the controller 131 turns off the transistors 57a and 57c and turns on 57b (36), that is, switches the light amount detection signal Vpd to the second range, and again the A / D converter 45. The A / D conversion instruction signal is output to read the light amount detection data Vpd converted by the A / D converter 45 and compared with the second original drawing determination threshold value Vt1 in the second range (37). If the light quantity detection data Vpd is equal to or greater than Vt1, “2” representing the second original drawing is written in the paper type register PMR (38). That is, it is determined that there is a second original diagram between the LEDs / PTr.

  However, if Vpd is less than the threshold value Vt1, the controller 131 turns off the transistors 57a and 57b and turns on 57c (39), that is, switches the light amount detection signal Vpd to the third range, and again the A / D converter 45. The A / D conversion instruction signal is output to the light amount detection data Vpd converted by the A / D converter 45, and compared with the threshold value Vt1 for determining the first type plain paper (45Kg) in the third range (40). . If the light quantity detection data Vpd is equal to or greater than Vt1, “3” representing the first type plain paper is written in the paper type register PMR (41). That is, it is determined that there is first type plain paper between the LED / PTr.

  However, if the light quantity detection data Vpd is less than Vt1, the light quantity detection data Vpd is compared with the threshold value Vt2 for determining recycled paper (and back paper) in the third range (42). If the light quantity detection data Vpd is equal to or greater than Vt2, “4” representing the recycled paper (and back paper) is written in the paper type register PMR (43). That is, it is determined that there is recycled paper (or back paper) between the LED / PTr.

  However, if the light quantity detection data Vpd is less than Vt2, the light quantity detection data Vpd is compared with the threshold value Vt3 for determining the second type plain paper 90Kg (and letterhead, colored paper 1) in the third range (44). If the light quantity detection data Vpd is equal to or greater than Vt3, “5” representing the second type plain paper (and letterhead, colored paper 1) is written in the paper type register PMR (45). That is, it is determined that there is the second type plain paper (or letterhead or colored paper 1) between the LED / PTr.

  However, if the light quantity detection data Vpd is less than Vt3, “6” representing the third type plain paper 180 kg (and thick paper, colored paper 2) is written in the paper type register PMR (46). That is, it is determined that there is third type plain paper (or thick paper or colored paper 2) between the LED / PTr.

  Since the determination of the paper type is completed, the power supply to the LED is stopped (47), all the switching transistors 57a, b, c are turned off (48), and the paper type determination of the paper type register PMR is performed on the operation board 20. Data is transmitted and the display of the paper type is instructed (49). In response to this, the operation board 20 converts the type data (1 to 6) into a common type name (the type shown in Table 1) using the conversion table in its internal memory and displays it on the display.

  The hardware of the second embodiment is the same as that of the first embodiment, and the outline of the control function of the process controller 131 of the second embodiment is the same as that of the first embodiment. The contents of (PPCa) are slightly different.

  FIG. 11 shows the contents of “image formation control” (PPCb) of the process controller 131 of the second embodiment. In this “image formation control” (PPCb), when the process controller 131 executes “paper type detection” (PMDA), the paper type data detected thereby is addressed to each paper feed stage defined in the nonvolatile memory NVRAM 132. Of the paper type register MRip (MRap addressed to the paper feed tray 103a, MRbp addressed to the paper feed tray 103b, MRcp addressed to the paper feed tray 103c and MRdp addressed to the paper feed tray 103d) (4), the process controller 131 determines that the image forming process condition (mainly development bias) corresponding to the detected paper type (= MRap paper type) is the same as the paper type register MRip (MRap). , A transfer voltage for transferring the toner image to the transfer belt 106, a paper suction voltage applied to the transport belt 107, and (Target temperature) is set (7), image formation on the one sheet is started (8), the number of image formation is counted up (9), and the designated number of image formation is reached. (10), if the specified number of sheets has been reached, the image forming control ends when the last image forming sheet is discharged. When the designated number of sheets is a continuous copy of a plurality of originals or a plurality of originals using ADF, the next paper feed is started (11), and the process proceeds to the continuous printing control under the circle A.

  By the way, when the detected paper type of the first paper feed sheet does not match the paper type of the paper type register MRip (MRap) addressed to the paper feed tray (103a) designated for paper feed, the paper type register MRip (MRap). The detected paper type data is updated and written in (6). Then, the image forming process condition corresponding to the detected paper type is determined and image forming is started (7 or less).

  As described above, in the case of the first start instruction after the power is turned on, or in the case of the first paper feed instruction from the paper feed stage after the paper tray is put in and out, the designated number of copies or prints is 2. Even in this case, if only the first sheet is fed to detect the paper type, and the detected paper type is different from the paper type held in the register MRip (MRap) before the current paper type detection, the paper replenishment is performed. Alternatively, the paper type data in the register MRip (MRap) is updated to the detected paper type because there is an exchange.

  Next, when it is not the first start instruction after the power is turned on, nor is it the first paper feed instruction from the paper feed stage immediately after loading / unloading of the paper feed tray, that is, the paper type held in the register MRip (MRap) of the NVRAM 132 If the paper type of the paper in the paper feed stage 103i (103a) can be estimated to match, the process controller 131 goes through steps 1 and 2 in FIG. 11 and in step 19b, the paper feed stage 103i designated for paper feed. The image forming process condition corresponding to the paper type held by the register MRip (MRap) addressed to (103a) is set as the image forming process condition of the image forming unit 135 (19b), and the image formation for the designated number of sheets is started (19b). 20). In this case, if the designated number of copies or prints is plural, the sheets are fed out sequentially from the designated paper feed stage in a predetermined sequence, the image forming speed (image forming number / time) is high, and depending on the image forming mode. In this case, the next and subsequent sheets are fed out from the sheet feeding tray before the leading edge of the first sheet hits the registration roller 105 and the sheet type is detected.

  However, in this embodiment, in order to detect the mixing of different paper types, the paper type is detected for each paper by “paper type detection” (PMDb). Then, the paper type detected by “paper type detection” (PMDb) is collated with the paper type held by the register MRip (MRap) addressed to the paper feed stage 103i (103a). Continuously, as long as the paper type of each feeding paper matches the paper type of the register MRip (MRap), image formation is continued up to the designated number (PMDb-12b-13-PMDb).

  However, if the paper type detected by “paper type detection” (PMDb) is different from the paper type held in the register MRip (MRap) addressed to the paper feed stage 103i (103a) (12b), the process controller 131 A “paper type error in the paper feed stage 103i (103a)” is notified via the operation board 20 (14), the paper feeding by the registration roller 105 is stopped, and the paper feeding from the paper feeding tray and the registration roller 105 are stopped. (15). Other functions of the second embodiment are the same as those of the first embodiment.

  The hardware of the third embodiment is the same as that of the first embodiment, and the outline of the control function of the process controller 131 of the third embodiment is the same as that of the first embodiment. The contents of (PPCc) are slightly different.

  FIG. 12 shows the contents of “image formation control” (PPCc) of the process controller 131 of the third embodiment. When “paper type detection” (PMDA) is executed, the paper type data detected thereby is a paper type register MRip addressed to each paper feed stage defined in the nonvolatile memory NVRAM 132 (MRap, paper feed tray addressed to the paper feed tray 103a). (4) MRbp addressed to 103b, MRcp addressed to paper feed tray 103c, and MRdp addressed to paper feed tray 103d) are compared with the paper type register MRip (MRap) addressed to the paper feed tray designated for paper feed (for example, 103a) (4 In the same case, the process controller 131 sets the image forming process conditions (mainly the development bias, the transfer voltage for transferring the toner image to the transfer belt 106, and the conveyor belt 107 corresponding to the detected paper type (= MRap paper type). (Sheet adsorption voltage and fixing target temperature) to be applied to (7), and image formation on the one sheet is started ( ) Count up the number of image formations by 1 (9), check whether the number of image formations reaches the specified number (10), and when the number reaches the specified number, exit the last image formation paper End image formation control. When the designated number of sheets is a continuous copy of a plurality of originals or a plurality of originals using ADF, the next paper feed is started (11), and the process proceeds to the continuous printing control under the circle A.

  By the way, when the detected paper type of the first paper feed sheet does not match the paper type of the paper type register MRip (MRap) addressed to the paper feed tray (103a) designated for paper feed, the detected paper type is set to the operation board 20. Whether the paper type is the same as the paper type set by the operator in the paper type register BRip (BRap) is checked (5). If they are the same, the paper type has been changed by paper replacement or paper replenishment in the corresponding paper feed stage (103a), so the detected paper type data is updated and written to the paper type register MRip (MRap) (6). Then, the image forming process condition corresponding to the detected paper type is determined and image forming is started (7 or less).

  As described above, in the case of the first start instruction after the power is turned on, or in the case of the first paper feed instruction from the paper feed stage after the paper tray is put in and out, the designated number of copies or prints is 2. Even in this case, only the first sheet is fed to detect the paper type, and the paper type is the paper type held by the register MRip (MRap) before the current paper type detection or the operation board 20 If it matches the register BRip (BRap) set by the input, the process proceeds to the designated number of image forming (paper feeding), but if it does not match, a paper type error of the corresponding paper feeding stage (103a) is notified (14), The image forming process is stopped, and the paper whose sheet type is detected is discharged without forming an image (15 to 17).

  As a result, there is no paper type setting by the operator, and conveyance of a paper type different from the previous paper type to the toner image transfer stage is prevented. In order to form an image on the different paper type, the operator may set the different paper type in the register BRip (BRap) of the operation board 20 by using the above-described “paper type data setting” (OPS). . However, since it is not possible to set a common paper type that is not indicated on the setting input screen (FIG. 7), an effect of preventing the use of paper types other than the paper type assigned to the copying machine (FIG. 7) can be expected.

  Next, when it is not the first start instruction after the power is turned on, nor is it the first paper feed instruction from the paper feed stage immediately after loading / unloading of the paper feed tray, that is, the paper type held in the register MRip (MRap) of the NVRAM 132 If the paper type of the paper in the paper feed stage 103i (103a) can be estimated to match, the process controller 131 goes through steps 1 and 2 in FIG. 11 and in step 19b, the paper feed stage 103i designated for paper feed. The image forming process condition corresponding to the paper type held by the register MRip (MRap) addressed to (103a) is set as the image forming process condition of the image forming unit 135 (19b), and the image formation for the designated number of sheets is started (19b). 20). In this case, if the designated number of copies or prints is plural, the sheets are fed out sequentially from the designated paper feed stage in a predetermined sequence, the image forming speed (image forming number / time) is high, and depending on the image forming mode. In this case, the next and subsequent sheets are fed out from the sheet feeding tray before the leading edge of the first sheet hits the registration roller 105 and the sheet type is detected.

  However, also in this embodiment, in order to detect the mixing of different paper types, the paper type is detected for each paper by “paper type detection” (PMDb). Then, the paper type detected by “paper type detection” (PMDb) is collated with the paper type held by the register MRip (MRap) addressed to the paper feed stage 103i (103a). Continuously, as long as the paper type of each feeding paper matches the paper type of the register MRip (MRap), image formation is continued up to the designated number (PMDb-12b-13-PMDb).

  However, if the paper type detected by “paper type detection” (PMDb) is different from the paper type held in the register MRip (MRap) addressed to the paper feed stage 103i (103a) (12b), the process controller 131 A “paper type error in the paper feed stage 103i (103a)” is notified via the operation board 20 (14), the paper feeding by the registration roller 105 is stopped, and the paper feeding from the paper feeding tray and the registration roller 105 are stopped. (15). Other functions of the third embodiment are the same as those of the first embodiment.

  The hardware of the fourth embodiment is the same as that of the first embodiment, and the outline of the control function of the process controller 131 of the fourth embodiment is the same as that of the third embodiment. The contents of (PPCc) are slightly different.

  FIG. 13 shows the contents of “image formation control” (PPCd) of the process controller 131 of the fourth embodiment. In this “image formation control” (PPCd), when a paper type error in the paper feed stage is detected and notified via the operation board 20 (14), the process controller 131 displays the image formation unit 135 (FIG. 2). The paper jam is stopped (21), and the paper jam is notified via the operation board 20 (22).

  Therefore, in the fourth embodiment, the operator removes the paper detected as the paper type error, and the paper detected as the paper type error and the paper fed out subsequently are transferred from the registration roller 105 to the conveying belt 107 and the fixing unit 108. Do not pass the transport route to the paper discharge tray. This prevents damage or deterioration of the mechanism elements on the transport route due to an inappropriate paper type. Other functions of the fourth embodiment are the same as those of the third embodiment.

1 is a front view showing an external appearance of a multi-function full color copying machine according to a first embodiment of the present invention. FIG. 2 is an enlarged longitudinal sectional view showing an outline of an image forming mechanism of the printer 100 shown in FIG. 1. It is a block diagram which shows the outline | summary of the image processing system of the copying machine shown in FIG. FIG. 4 is a block diagram showing a configuration of a paper type discrimination system centering on a light projecting circuit board 50, a light receiving circuit board 54 shown in FIG. 2, a process controller 131 and an interface 136 shown in FIG. The relationship between the target voltage Vm generated inside the APC 43 shown in FIG. 4 and the threshold values Vt1 to Vt3 referred to by the process controller 131 in the paper type discrimination processing PMMa and PMDb shown in FIG. 4A is a graph in the first range setting in which the switching transistor 57a shown in FIG. 4 is turned on and 57b and 57c are turned off. FIG. 4B is a graph showing that the transistor 57b is turned on and 57a and 57c are turned off. (C) shows the transistor in the third range setting in which the transistor 57c is turned on and 57a and 57b are turned off. 4 is a flowchart showing an outline of setting paper type data on the operation board 20 shown in FIG. 3. FIG. 4 is an enlarged plan view showing a paper type input screen of the liquid crystal touch panel on the operation board 20 shown in FIG. 3. 4 is a flowchart showing an outline of image formation control (PPCa) executed by a process controller 131 shown in FIG. 3. 9 is a flowchart showing an outline of “paper type detection” (PMDa) shown in FIG. 8, which is a paper type determination process executed by a process controller 131. It is a flowchart which shows the content of the "light quantity adjustment" (31) shown in FIG. It is a flowchart which shows the outline | summary of the image formation control (PPCb) which the process controller 131 of 2nd Example of this invention performs. It is a flowchart which shows the outline | summary of the image formation control (PPCc) which the process controller 131 of 3rd Example of this invention performs. It is a flowchart which shows the outline | summary of the image formation control (PPCd) which the process controller 131 of 4th Example of this invention performs.

Explanation of symbols

10: Color document scanner 20: Operation board 30: Automatic document feeders 41M, 41C, 41Y, 41K: Laser emitter 43: Automatic light quantity controller (APC)
50: Emitting circuit board 54: Light receiving circuit board 100: Color printer PC1: Personal computer PB ×: Exchanger PN: Communication line 102: Optical writing unit 103a-d: Paper feed tray 105: Registration roller pair 106: Intermediate transfer belt 107 : Conveying belt 1068: Fixing units 110M, 110C, 110Y, and 110K: Photosensitive units 111M, 111C, 111Y, and 111K: Photosensitive drums 120M, 120C, 120Y, and 120K: Developer ACP: Image data processing device CDIC: Image data interface Control IMAC: Image memory access control IPP: Image data processor HDD: Hard disk device

Claims (7)

Image forming means for forming a visible image on paper;
Paper feeding means for feeding paper from the paper feed stage to the image forming means and discharging the paper on which the image forming means has formed an image;
A paper type discriminating unit for discriminating a paper type of the paper fed out by the paper feeding unit to the image forming unit according to a paper thickness or a transmitted light amount;
A register for holding paper type data of the paper in the paper feed stage; and
The image forming process condition corresponding to the paper type data of the register is set in the image forming means, and the paper type determined by the paper type determining means of the paper sent to the image forming means for image formation under the image forming process condition An image forming control means for stopping the paper feeding to the image forming means when the seed does not match the paper type data of the register;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the register includes an operator-specified paper type register that holds paper type data specified by an operator.   The image forming apparatus according to claim 1, wherein the register includes a paper type register of a determination result that holds the paper type determined by the paper type determination unit.   In response to the start instruction, the image forming means refers to information on whether or not paper is not fed immediately after the paper loading operation for the paper feed stage, and is not yet fed immediately after the paper loading operation. 4. The delivery of the second sheet is suspended until the first sheet is fed out from the paper feed stage and the determination of the sheet type by the sheet type determination unit is finished. 5. Image forming apparatus.   Immediately after the power is turned on, the image forming means sends out the first sheet from the paper feed stage in response to a start instruction until the second sheet type is determined by the sheet type determining means. The image forming apparatus according to claim 1, wherein the delivery of the paper is suspended.   The image forming means stops sending the paper to the image forming means when the paper type determined by the paper type determining means of the paper sent to the image forming means does not match the paper type data of the register. The image forming apparatus according to claim 1, wherein the image is stopped and only the paper is discharged and conveyed. The image forming means stops image formation and stops paper conveyance when the paper type determined by the paper type determination means of the paper sent to the image forming means does not match the paper type data of the register. Item 6. The image forming apparatus according to any one of Items 1 to 5.

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