JP2004277057A - Image forming apparatus, paper feeding device, paper type information acquisition method, paper feeding control method, and image formation operation control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic detection function for type of paper including at least paper thickness utilized in variable setting of fixed temperature to utilize the result of detection effectively and securely and eliminate waste of time and energy in an image formation process. <P>SOLUTION: A tip part of one paper is fed by predetermined amount by a separation paper feeding means from a paper storage part to detect type of paper by a paper type detection means (S2, S3, S4) at timing prior to paper feeding command (Y of S1) and obtain paper type information before receiving paper feeding command (S11). Proper setting by utilizing paper type information effectively and securely becomes possible concerning image formation process of an image formation means before receiving paper feeding command, thereby eliminating waste of time and energy in the image formation process. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as an electrophotographic printer, a copying machine, a facsimile, and an ink jet printer for forming an image on paper of different paper types, a paper feeding apparatus used in the image forming apparatus, The present invention relates to a paper type information obtaining method, a paper feed control method, and an image forming operation control method used in an image forming method.
[0002]
[Prior art]
Generally, in this type of image forming apparatus, in addition to normal plain paper, thick plain paper, OHP paper, a second original drawing, or the like may be used as paper. Such a difference in paper type affects transferability, fixability, and the like. For example, in an electrophotographic image forming apparatus, for example, the transfer current of a transfer device that transfers an image (toner) to paper is changed depending on the paper thickness. Higher image quality is achieved by changing the fixing temperature of the fixing device, or changing the image forming speed (substantially the same as the sheet conveying speed) (for example, see Patent Documents 1 and 2).
[0003]
At this time, conventionally, the paper type information such as the paper thickness has been visually specified by an operator and manually designated by the operator. Also, a proposal has been made to automatically detect the paper type (for example, the distinction between plain paper and OHP paper) using a transmission type optical sensor or the like. There are various other proposals regarding detection of paper type such as paper thickness (for example, see Patent Documents 3 and 4).
[0004]
With the recent networking of office environments, a common use form in which one image forming apparatus (printer) is shared by a plurality of host computers (PCs) is common, and the distance between the PC and the printer is often not long. Below, the ability to automatically detect the paper type of a paper set in a paper feed cassette or the like of a printer is an important factor for obtaining a desired printed matter.
[0005]
[Patent Document 1]
JP-A-7-196207
[Patent Document 2]
JP-A-8-254927
[Patent Document 3]
JP-A-2002-167081
[Patent Document 4]
JP-A-2002-352936
[Patent Document 5]
JP 2003-29582 A
[0006]
[Problems to be solved by the invention]
However, in the case of these conventional examples, although the paper type (or paper thickness) of the paper to be fed can be automatically detected by using a transmission type sensor or the like, an operation panel or a PC operation or the like is used. A paper supply command is issued to the corresponding paper cassette based on the print instruction by the printer, and the paper type (or paper thickness) is determined in the process of feeding and conveying the paper from the paper cassette toward the photoconductor or the like. I try to detect. As a result, for example, when the fixing temperature is variably controlled according to the paper type, if the fixing temperature at that time is too high for the paper type of the fed paper, the paper is temporarily stopped and the paper is stopped. One has to wait until the fixing temperature drops to the seed. In this case, the fixing temperature, which is increased by consuming the time, power, and energy (energy), is decreased over time, which is wasteful.
[0007]
Further, for example, in the case of a tandem-type full-color image forming apparatus (printer) in which a plurality of (generally four) photoconductors are arranged in parallel on an intermediate transfer belt to enable full-color printing, a photoconductor for the first color is used. Since the distance from the image to the transfer position is long and it takes time for the formed image to reach this transfer position, the printing time is reduced by starting the image formation on the photoconductor at the same time as the paper feed command. (By the way, in the case of a black and white printer, image formation is started after the paper reaches the registration rollers.) Therefore, in the case of such a tandem type full-color image forming apparatus, when the paper type of the paper fed and conveyed from the paper feed cassette is known, the image forming process has already been started, and the detected paper type is If the image forming speed and the image forming conditions are not optimum, the angle and the formed image must be re-created from the beginning, resulting in waste.
[0008]
According to Patent Document 5, a paper type detecting unit is provided at a position where the paper type can be determined before the start of the paper feeding operation. Specifically, a reflection for detecting the paper type at a specific portion of the paper feed tray is provided. Although it is shown that a paper-type optical sensor is provided, the paper thickness cannot be detected by the reflective optical sensor from the paper stacked on the paper feed tray, and when paper thickness information is required, It cannot be applied.
[0009]
An object of the present invention is to provide an automatic detection function of a paper type including at least a paper thickness used for variably setting a fixing temperature and the like. Moreover, it is to eliminate waste of time and energy.
[0010]
SUMMARY OF THE INVENTION It is an object of the present invention to prevent a sheet fed for a sheet type detecting operation from being damaged.
[0011]
[Means for Solving the Problems]
The image forming apparatus according to the first aspect of the present invention includes a sheet storage unit for stacking and holding sheets of paper, a separation sheet feeding unit for separating and feeding the sheets one by one from the sheet storage unit, and a sheet feeding unit for separating and feeding the sheets. Image forming means for forming an image on the paper sheet, paper type detecting means for detecting a paper type including at least the thickness of the paper fed by the separation paper feeding means, and At the timing, a paper type detecting paper feeder for causing the separated paper feed unit to feed a leading end of one sheet by a predetermined amount from the paper storage unit and detecting the paper type of the sheet by the paper type detection unit. Timing control means.
[0012]
Therefore, at a timing prior to the paper feed command, the leading end of one sheet is fed from the paper storage unit by the separate paper feed unit by a predetermined amount, and the paper type of the paper is detected by the paper type detection unit. Since the paper type information can be acquired before receiving the paper feed command, the image forming process of the image forming unit can be properly and effectively and properly set before the paper feed command is received. Moreover, waste of time and energy can be eliminated.
[0013]
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the detected paper type information includes a distinction between plain paper, OHP paper, and the second original drawing, in addition to the paper thickness.
[0014]
Therefore, as the paper type information, it is possible to handle the distinction between the plain paper, the OHP paper, and the second original drawing in addition to the paper thickness generally used in this type of image forming apparatus. It can be used for conversion. Particularly, regarding the paper thickness, since only one paper is separated and fed and detected by the paper type detecting means, it is possible to obtain reliable information.
[0015]
According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the paper type detection unit detects the paper type of the paper in a non-contact manner using an optical measurement method.
[0016]
Therefore, since only one sheet of paper is separated and fed, and the paper type such as the paper thickness is detected, the paper type detecting means is reliably and easily detected by a general non-contact method using an optical measuring method. can do.
[0017]
According to a fourth aspect of the present invention, in the image forming apparatus of the third aspect, the paper type detection unit detects the paper type using a transmission optical sensor that detects a transmittance of the paper.
[0018]
Therefore, only one sheet of paper is separated and fed, and the paper type such as the paper thickness is detected. Therefore, the paper type detecting means is reliably and easily detected by an optical measuring method, particularly a method using a transmission type optical sensor. can do.
[0019]
According to a fifth aspect of the present invention, in the image forming apparatus according to the first or second aspect, the paper type detection unit detects a paper type of the paper by converting a mechanical displacement amount into an electric signal.
[0020]
Therefore, since only one sheet is separated and fed, and the paper type such as the paper thickness is detected, the paper type detecting means generally uses a mechanical displacement method of converting a mechanical displacement amount into an electric signal. Can be reliably and easily detected by a simple method.
[0021]
According to a sixth aspect of the present invention, in the image forming apparatus according to the first or second aspect, the paper type detection unit detects the paper type of the paper using a capacitance sensor that measures a capacitance of the paper.
[0022]
Therefore, since only one sheet of paper is separated and fed, and the paper type such as the paper thickness is detected, the paper type detection means can be reliably and easily detected by a general non-contact method using a capacitance sensor. Can be.
[0023]
According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects, the image forming apparatus includes a plurality of the paper storage units, and the paper type detection unit is individually provided for each of the paper storage units.
[0024]
Therefore, since a plurality of paper storage units are individually provided with paper type detection means for each paper storage unit, paper type information of the paper held in each paper storage unit can be obtained without omission. Appropriate image forming process control according to the paper type information.
[0025]
According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, the paper type detection paper supply timing control means determines at least a timing of the image formation apparatus as a timing prior to a paper supply instruction. When the power is turned on, the paper type detecting operation of the paper is performed.
[0026]
Therefore, by performing the paper type detection operation of the paper at least when the power of the image forming apparatus is turned on, even if the paper type is changed before the power is turned on, an appropriate response according to the paper type is performed. It becomes possible.
[0027]
According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, the paper type detection paper supply timing control means controls the paper storage unit as a timing prior to a paper supply instruction. Then, when the paper is loaded, a paper type detection operation of the paper is performed.
[0028]
Therefore, since the paper type is changed when paper is loaded into the paper storage unit, the paper type detection operation is performed when paper is loaded into the paper storage unit, so that the paper type change is performed. , And appropriate measures can be taken according to the type of paper loaded in the paper storage unit.
[0029]
According to a tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, the paper storage unit includes a paper feed cassette that can be pulled out and stored in the image forming apparatus main body, and the paper type detection paper feeder is provided. The timing control means causes the sheet type of the sheet to be detected each time the drawn-out sheet cassette is stored in the image forming apparatus main body.
[0030]
Therefore, when the paper storage unit is a paper feed cassette, the pull-out / storage operation of the paper feed cassette may be performed at the time of jam clearance or the like. By doing so, it is possible to reliably cope with a change in the paper type accompanying the loading of new paper, and it is possible to take appropriate measures according to the paper type of the paper loaded in the paper feed cassette.
[0031]
According to an eleventh aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, the paper type detection paper supply timing control means determines the timing prior to the paper supply instruction in response to the preceding paper supply instruction. After the paper is fed from the paper storage unit based on the sheet storage unit, a paper type detection operation of the paper is performed on the paper storage unit until a next paper supply command is issued.
[0032]
Therefore, by performing paper type detection for the next paper every time paper is fed for image formation, for example, in a case where paper of different paper types is mixedly loaded in the paper storage unit, Also, the paper type can be acquired for each sheet in advance, and appropriate measures can be taken according to the paper type of each loaded paper.
[0033]
According to a twelfth aspect of the present invention, in the image forming apparatus according to any one of the first to eleventh aspects, the paper storage unit includes a paper cassette that can be pulled out and stored in the image forming apparatus main body. A storage unit for storing the paper type information detected by the paper type detection unit in a storage unit, and the paper fed by a predetermined amount is pulled back into the corresponding paper feed cassette after the paper type detection unit detects the paper type. And a pull-back means.
[0034]
Therefore, in the case of a paper cassette that can be pulled out, if a predetermined amount of paper is kept fed for detecting the paper type, the paper may be damaged by the operation of pulling out the paper cassette. By causing the paper to be pulled back into the paper cassette after the paper type is detected, it is possible to prevent the paper from being damaged due to the operation of pulling out the paper cassette.
[0035]
According to a thirteenth aspect of the present invention, in the image forming apparatus according to the twelfth aspect, after a predetermined amount of the sheet is fed by the separation sheet feeding unit, the sheet is pulled back into the sheet feeding cassette by the pulling-back unit. A warning unit is provided for warning that the drawing operation of the sheet cassette is prohibited.
[0036]
Therefore, in realizing the invention of claim 12, if the sheet cassette is pulled out before the sheet is pulled back, there is a possibility that the sheet is damaged, but the operation of pulling out the sheet cassette is prohibited. Is warned, and the operator is alerted, thereby preventing the paper from being damaged due to the operation of pulling out the paper feed cassette.
[0037]
According to a fourteenth aspect of the present invention, in the image forming apparatus according to the twelfth aspect, after a predetermined amount of the sheet is fed by the separation sheet feeding unit, until the sheet is pulled back into the sheet feeding cassette by the pull-back unit. And a lock unit for prohibiting the drawing operation of the sheet cassette.
[0038]
Therefore, in realizing the invention of claim 12, if the sheet cassette is pulled out before the sheet is pulled back, there is a possibility that the sheet may be damaged. By forcibly prohibiting the sheet by the lock means, it is possible to reliably prevent the sheet from being damaged due to the operation of pulling out the sheet cassette.
[0039]
According to a fifteenth aspect of the present invention, in the image forming apparatus according to the twelfth aspect, the pull-back means has an interlocking mechanism for pulling the paper back into the paper feed cassette in conjunction with a pull-out operation of the paper feed cassette.
[0040]
Therefore, in realizing the invention of claim 12, if the paper feed cassette is pulled out before the paper is pulled back, there is a possibility that the paper will be damaged. Since the paper is pulled back into the paper feed cassette in conjunction with the paper cassette pull-out operation, it is possible to reliably prevent the paper from being damaged due to the paper feed cassette pull-out operation without restricting the paper feed cassette pull-out operation.
[0041]
According to a sixteenth aspect of the present invention, in the image forming apparatus according to any one of the first to eleventh aspects, the paper storage unit includes a paper cassette that can be pulled out and stored in the image forming apparatus main body. The paper feed cassette integrally includes the separation paper feed unit and the paper type detection unit, and can be pulled out and stored in the image forming apparatus main body.
[0042]
Therefore, when a paper feed cassette is included in the paper storage unit, the paper feed cassette is provided with a separate paper feed unit and a paper type detection unit so that it can be pulled out and stored in the image forming apparatus main body. Even if a predetermined amount of paper is fed to detect the paper type, the separation paper feeding unit and the paper type detection unit are also pulled out integrally with the pulling out operation of the paper feed cassette. Without restricting the operation of pulling out the paper cassette, it is possible to reliably prevent the paper from being damaged by the operation of pulling out the paper cassette. In addition, since the sheet pull-back operation is not required, the control is simplified, the sheet can be fed to the image forming unit, and the processing speed can be increased.
[0043]
According to a seventeenth aspect of the present invention, in the image forming apparatus according to any one of the first to sixteenth aspects, the image forming means forms an image by an electrophotographic method, Fixing temperature setting means for variably setting a fixing temperature in accordance with paper type information obtained by the detection of the paper type detecting means at a timing prior to a sheet feeding instruction; and And paper feed control means for feeding and feeding paper toward the printer.
[0044]
Therefore, in the case of the electrophotographic image forming means, a fixing device is provided, but after the fixing temperature is variably set in accordance with the paper type information acquired in advance at a timing prior to the paper feed command, the paper is actually fed and fed. Is performed, there is no need to reset the fixing temperature, and the waste of time and energy involved in resetting the fixing temperature can be eliminated.
[0045]
According to an eighteenth aspect of the present invention, in the image forming apparatus according to any one of the first to sixteenth aspects, when a paper feed instruction is received, the image data is acquired by the detection of the paper type detection unit at a timing prior to the paper feed instruction. Process speed setting means for variably setting the process speed of the image forming means in accordance with the paper type information, and paper feed control means for feeding and conveying the paper toward the image forming means after variably setting the process speed And.
[0046]
Accordingly, although the process speed of the image forming means varies depending on the paper type, the process speed is variably set in accordance with the paper type information acquired in advance at a timing prior to the paper feed instruction, and then the actual feeding of the paper is performed. By performing the paper conveyance, there is no need to re-form the image, and it is possible to eliminate the waste of time and energy associated with the re-formation.
[0047]
According to a nineteenth aspect of the present invention, in the image forming apparatus according to any one of the first to sixteenth aspects, when a paper feed command is received, the image data is acquired by detection of the paper type detection unit at a timing prior to the paper feed command. Image forming condition setting means for variably setting image forming conditions of the image forming means in accordance with the paper type information, and paper feeding for feeding and conveying the sheet toward the image forming means after variably setting the image forming conditions Transport control means.
[0048]
Therefore, the image forming conditions of the image forming means, for example, the transfer current and the like, have different appropriate conditions depending on the paper type, but the image forming conditions are variably set according to the paper type information obtained in advance at a timing prior to the paper feed command. By actually feeding and transporting the paper after this, there is no need to re-form the image, and it is possible to eliminate the time and energy waste associated with the re-formation.
[0049]
According to a twentieth aspect of the present invention, there is provided a sheet feeding apparatus which is capable of being pulled out and stored in an image forming apparatus main body, and a sheet feeding cassette for stacking and holding sheets, and separately feeding the sheets one by one from the sheet feeding cassette. Separation paper feeding means, paper type detection means for detecting a paper type including at least the paper thickness of the paper fed by the separation paper feeding means, and one sheet of paper from the paper feeding cassette by the separation paper feeding means An interlocking mechanism that feeds the leading end of the sheet by a predetermined amount and pulls the sheet supplied for the detection of the sheet type by the sheet type detection unit back into the sheet feeding cassette in conjunction with a pull-out operation of the sheet feeding cassette; Withdrawal means having
[0050]
Therefore, it is possible to provide a sheet feeding device suitable for application to the image forming apparatus according to the first to twelfth aspects.
[0051]
According to a twenty-first aspect of the present invention, there is provided a sheet feeding device which is capable of being pulled out and stored in the image forming apparatus main body, and which holds a sheet in a stacked state, and which is integrated with the sheet feeding cassette and is provided with the sheet feeding cassette. Separation paper feeding means for separating and feeding paper one by one, and paper type detection integrated with the paper feeding cassette and detecting a paper type including at least a paper thickness of the paper fed by the separation paper feeding means Means.
[0052]
Accordingly, it is possible to provide a sheet feeding device suitable for application to the image forming apparatus according to the sixteenth aspect.
[0053]
23. The paper type information acquiring method according to claim 22, wherein the paper sheets stacked and held in the paper storage unit are separately fed one by one by a separate paper feeding unit, and an image is formed on the fed paper by an image forming unit. A paper type information acquisition method used in an image forming method for forming, wherein a paper type detection unit that detects a paper type including at least a paper thickness of the paper fed by the separation paper supply unit is used. At a timing prior to the instruction, the leading end of one sheet is fed by a predetermined amount from the sheet storage unit by the separation sheet feeding unit, and the sheet type of the sheet is detected by the sheet type detecting unit. Get information.
[0054]
Therefore, at a timing prior to the paper feed command, the leading end of one sheet is fed from the paper storage unit by the separate paper feed unit by a predetermined amount, and the paper type of the paper is detected by the paper type detection unit. Since the paper type information can be acquired before receiving the paper feed command, the image forming process of the image forming unit can be properly and effectively and properly set before the paper feed command is received. Moreover, waste of time and energy can be eliminated.
[0055]
According to a twenty-third aspect of the present invention, in the paper type information acquiring method according to the twenty-second aspect, at least when the power of the image forming apparatus is turned on, the paper type detection operation is performed as a timing prior to the paper supply instruction. Added paper type information.
[0056]
Therefore, by performing the paper type detection operation at least when the power of the image forming apparatus is turned on, even if the paper type is changed before the power is turned on, it is possible to appropriately cope with the paper type. It becomes.
[0057]
According to a twenty-fourth aspect of the present invention, in the paper type information acquiring method according to the twenty-second aspect, the paper type detection operation is performed when the paper is loaded into the paper storage unit, as the timing prior to the paper supply instruction. It was made to perform and the paper type information was acquired.
[0058]
Therefore, since the paper type is changed when paper is loaded into the paper storage unit, the paper type detection operation is performed when paper is loaded into the paper storage unit, so that the paper type change is performed. , And appropriate measures can be taken according to the type of paper loaded in the paper storage unit.
[0059]
According to a twenty-fifth aspect of the present invention, in the paper type information acquiring method according to the twenty-fourth aspect, the paper storage unit includes a paper supply cassette that can be pulled out and stored in the image forming apparatus main body, and the drawn out paper supply is provided. Each time the cassette is stored in the image forming apparatus main body, the paper type detection operation is performed to obtain the paper type information.
[0060]
Therefore, when the paper storage unit is a paper feed cassette, the pull-out / storage operation of the paper feed cassette may be performed at the time of jam clearance or the like. By doing so, it is possible to reliably cope with a change in the paper type accompanying the loading of new paper, and it is possible to take appropriate measures according to the paper type of the paper loaded in the paper feed cassette.
[0061]
According to a twenty-sixth aspect of the present invention, in the paper type information acquiring method according to the twenty-second aspect, as the timing prior to the paper feed instruction, after the paper is fed from the paper storage unit based on the preceding paper feed instruction, Until the paper supply command is issued, the paper type detection operation is performed on the paper storage unit to obtain the paper type information.
[0062]
Therefore, by performing paper type detection for the next paper every time paper is fed for image formation, for example, in a case where paper of different paper types is mixedly loaded in the paper storage unit, Also, the paper type can be acquired for each sheet in advance, and appropriate measures can be taken according to the paper type of each loaded paper.
[0063]
According to a sheet feeding control method of the present invention, sheets stacked and held in a sheet storage section including a sheet cassette which can be pulled out and stored in at least the image forming apparatus main body are separated one by one by a separation sheet feeding means. A paper feed control method used in an image forming method for feeding paper and forming an image on the fed paper by an image forming means, wherein at least a thickness of the paper fed by the separated paper feed means Using a paper type detecting means for detecting a paper type including the above, at a timing prior to a paper feeding command, the leading end of one sheet of paper is fed from the paper storage unit by the predetermined amount by the separation paper feeding means. A paper type detection feeding step for detecting the paper type of the paper by the paper type detection means, and the paper supply corresponding to the paper fed by a predetermined amount from the paper feed cassette after the paper type detection means detects the paper type. In paper cassette And a step pullback to come back, the.
[0064]
Therefore, in the case of a paper cassette that can be pulled out, if a predetermined amount of paper is kept fed for detecting the paper type, the paper may be damaged by the operation of pulling out the paper cassette. By causing the paper to be pulled back into the paper cassette after the paper type is detected, it is possible to prevent the paper from being damaged due to the operation of pulling out the paper cassette.
[0065]
29. The image forming operation control method according to claim 28, wherein the sheets stacked and held in the sheet storage unit are separated and fed one by one by a separation feeding unit, and an image is formed on the fed sheet by an electrophotographic method. An image forming operation control method used in an image forming method in which an image is formed by a forming unit, wherein a sheet type detecting unit that detects a sheet type including at least a sheet thickness of the sheet fed by the separation sheet feeding unit is provided. At a timing prior to a paper feed command, the leading end of one sheet is fed from the paper storage unit by the separation paper feed unit by a predetermined amount, and the paper type of the paper is detected by the paper type detection unit. A paper type information obtaining step of obtaining the paper type information, and when a paper feed instruction is received, the fixing temperature is set in accordance with the paper type information obtained in the paper type information obtainment step at a timing prior to the paper feed instruction. Variable setting Including a deposition temperature setting step, and a sheet feed conveyance step of conveying the sheet feeding toward said image forming means the sheet after the variable setting of the fixing temperature.
[0066]
Therefore, in the case of the electrophotographic image forming means, a fixing device is provided, but after the fixing temperature is variably set in accordance with the paper type information acquired in advance at a timing prior to the paper feed command, the paper is actually fed and fed. Is performed, there is no need to reset the fixing temperature, and the waste of time and energy involved in resetting the fixing temperature can be eliminated.
[0067]
29. The image forming operation control method according to claim 29, wherein the sheets stacked and held in the sheet storage section are separated and fed one by one by a separation feeding unit, and an image is formed on the fed sheet by the image forming unit. An image forming operation control method used in an image forming method for forming a sheet, wherein the sheet feeding unit uses a sheet type detecting unit that detects a sheet type including at least a sheet thickness of the sheet fed by the separation sheet feeding unit. At a timing prior to the instruction, the leading end of one sheet is fed by a predetermined amount from the sheet storage unit by the separation sheet feeding unit, and the sheet type of the sheet is detected by the sheet type detecting unit. A paper type information obtaining step of obtaining information; and a process speed of the image forming unit, in response to the paper type information obtained in the paper type information obtaining step at a timing prior to the paper feed instruction when a paper feed instruction is received. Variable setting That includes a process speed setting step, and a sheet feed conveyance step of conveying the sheet feeding toward said image forming means the sheet after the variable setting of the process speed.
[0068]
Accordingly, although the process speed of the image forming means varies depending on the paper type, the process speed is variably set in accordance with the paper type information acquired in advance at a timing prior to the paper feed instruction, and then the actual feeding of the paper is performed. By performing the paper conveyance, there is no need to re-form the image, and it is possible to eliminate the waste of time and energy associated with the re-formation.
[0069]
31. The image forming operation control method according to claim 30, wherein the sheets stacked and held in the sheet storage unit are separated and fed one by one by a separation feeding unit, and an image is formed on the fed sheet by an electrophotographic method. An image forming operation control method used in an image forming method in which an image is formed by a forming unit, wherein a sheet type detecting unit that detects a sheet type of the sheet fed by the separation sheet feeding unit is used to execute a sheet feeding command. At a timing prior to the time, the leading end of one sheet is fed from the sheet storage unit by the separation sheet feeding unit by a predetermined amount, and the sheet type including at least the sheet thickness of the sheet is detected by the sheet type detecting unit. A paper type information obtaining step of obtaining the paper type information, and, when a paper supply instruction is received, at the timing prior to the paper supply instruction, the image forming is performed in accordance with the paper type information obtained by the paper type information obtaining step. Image of means Including an image forming condition setting step for variably setting the growth conditions, and a sheet feed conveyance step of conveying the sheet feeding toward said image forming means the sheet after the variable setting of the image forming condition.
[0070]
Therefore, the image forming conditions of the image forming means, for example, the transfer current and the like, have different appropriate conditions depending on the paper type, but the image forming conditions are variably set according to the paper type information obtained in advance at a timing prior to the paper feed command. By actually feeding and transporting the paper after this, there is no need to re-form the image, and it is possible to eliminate the time and energy waste associated with the re-formation.
[0071]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
[0072]
The image forming apparatus of the present embodiment shows an example of application to a tandem type full-color image forming apparatus using an electrophotographic method. FIG. 1 is a vertical sectional front view schematically showing the entire configuration of the full-color image forming apparatus. An image forming section (printer engine) 2 serving as an image forming means is disposed substantially at the center of the apparatus main body 1. A sheet feeding unit 3 serving as a sheet feeding device is disposed immediately below the sheet feeding unit. The paper supply unit 3 is provided with, for example, four paper cassettes 4a to 4d each serving as a paper storage unit. These paper feed cassettes 4a to 4d are provided so as to be able to be pulled out and stored in the front and rear direction (in the drawing, front and back sides of the drawing) with respect to the apparatus main body 1. A reading section (scanner) 5 for reading a document image is provided above the image forming section 2. Further, on the downstream side (the left side in the drawing) of the image forming section 2 in the sheet conveying direction, a sheet discharge tray 7 for discharging the sheet 6 on which the image has been formed is provided. Note that a manual tray 8 is provided on the upstream side (the right side in the drawing) of the image forming unit 2 in the sheet conveyance direction, which is a sheet storage unit for manually feeding the sheet 6.
[0073]
Here, in the image forming section 2, a plurality of image forming sections 10 for yellow (Y), magenta (M), cyan (C), and black (K) are provided above the intermediate transfer belt 9 formed of an endless belt. Are juxtaposed. In each image forming unit 10, electrophotographic process members or devices such as a charging device 12, an exposing unit, a developing device 13, and a cleaning device 14 are arranged along the outer periphery of a drum-shaped photoreceptor 11 provided for each color. Have been. The charging device 12 performs a charging process on the surface of the photoconductor 11, and a laser beam from an exposure device 15 that irradiates the surface of the photoconductor 11 with laser light to image information is irradiated in an exposure unit. The developing device 13 develops and visualizes the electrostatic latent image formed by exposing the surface of the photoconductor 11 with toner, and the cleaning device 14 removes and collects the toner remaining on the surface of the photoconductor 11 after transfer.
[0074]
As an image forming process, an image for each color is formed on the intermediate transfer belt 9, and four colors are superimposed on the intermediate transfer belt 9 to form one color image. At that time, first, the yellow (Y) toner is developed in the yellow (Y) image forming unit and transferred to the intermediate transfer belt 9. Next, the magenta (M) image forming unit develops the magenta toner and transfers it to the intermediate transfer belt 9. Next, in a cyan (C) image forming section, the cyan toner is developed and transferred onto the intermediate transfer belt 9, and finally, the black (K) toner is developed and transferred onto the intermediate transfer belt 9. And a full-color toner image in which four colors are superimposed is formed. Then, the four-color toner images transferred onto the intermediate transfer belt 9 are transferred to the paper 6 fed from the paper feed unit 3 by the transfer device 16 and fixed by the fixing device 17, and then discharged by the discharge roller The paper 18 is discharged to the paper discharge tray 7. On the other hand, after the full-color toner image is transferred, the toner remaining on the surface of the intermediate transfer belt 9 is removed and collected by the cleaning device 21.
[0075]
The paper feed unit 3 has paper feed cassettes 4a to 4d each of which holds paper 6 in a stacked manner, as shown in a schematic diagram of FIG. In the vicinity of the paper feed port of each of the paper feed cassettes 4a to 4d, a pickup roller 22 which comes into contact with the uppermost paper of the stacked paper 6 and the paper 6 drawn out of the paper feed cassette 4 by the pickup roller 22 are supplied. A paper feed roller 23 for feeding paper and a reverse roller 24 for facing and contacting the paper feed roller 23 to separate and feed the paper 6 one by one are provided. These rollers 22 to 24 constitute an FRR type separation sheet feeding unit 25. Similar separation and feeding means 25 is provided for the manual feed tray 8 as well.
[0076]
The paper trays 4 a to 4 d, the manual tray 8, and the registration roller 20 are connected by a conveyance path 26, and the paper 6 fed from an arbitrary paper supply location is transferred to the registration roller 20 via the conveyance path 26. Transported to Here, the registration roller 20 temporarily stops the conveyance of the sheet 6 and re-adjusts the sheet 6 at a timing such that the positional relationship between the toner image on the intermediate transfer belt 9 and the leading end of the sheet 6 becomes a predetermined positional relation. Send out. The registration roller 20 functions similarly for the paper 6 conveyed from the manual feed tray 8.
[0077]
In the reading section 5, in order to scan a document (not shown) placed on the contact glass 31, first and second traveling bodies 32 and 33 each equipped with a document illumination light source and a mirror. Reciprocates. The image information scanned by the traveling bodies 32 and 33 is condensed by a lens 34 on an image forming surface of a CCD 35 provided behind, and is read as an image signal by the CCD 35. The read image signal is digitized and processed. Then, based on the image-processed signal, light is written on the surface of the photoconductor 11 by the light emission of the laser diode LD (not shown) in the exposure device 15, and an electrostatic latent image is formed. The optical signal from the LD reaches the photoconductor 11 via a known polygon mirror or lens. An automatic document feeder 36 that automatically feeds a document onto the contact glass 31 is mounted above the reading unit 5.
[0078]
The full-color image forming apparatus according to the present embodiment has a control device (not shown) in addition to a function as a so-called digital full-color copying machine that reads an original by optical scanning, digitizes and copies it on paper as described above. Multifunction machine (MFP) having a facsimile function of exchanging image information of a document with a remote location and a so-called printer function of printing image information handled by a computer on paper. An image formed by any of the functions is formed on a sheet 6 by a similar image forming process, and is discharged to a discharge tray 7 and stored.
[0079]
Here, in the present embodiment, paper type detecting means 41a to 41e are individually provided for each of the paper feed cassettes 4a to 4d and the manual feed tray 8. Each of these paper type detecting means 41a to 41e has the same configuration, and the paper type of one sheet 6 fed separately from the rollers 23 and 24 is detected in a non-contact manner using an optical measurement method. It is to detect. As a representative example, referring to FIG. 3 showing the sheet cassette 4a in an enlarged manner, in the present embodiment, the light emitting element 42 and the light receiving element 43 are opposed to the transport path at a position immediately after the rollers 23 and 24. The transmissivity of the paper 6 fed to the transmissive optical sensor 44 is detected using the transmissive optical sensor 44 disposed therein, and the transmissivity is set such that the paper type is set for each transmissivity range as described below. The paper type including the paper thickness is detected by referring to the paper type table.
[0080]
Next, a schematic configuration example of a control system of the full-color image forming apparatus according to the present embodiment is shown in a block diagram of FIG. The control system according to the present embodiment includes a system control unit 51, an image input unit 52, an image processing unit 53, a storage unit 54, a paper feeding unit 3, a writing unit 15, an image forming unit 2, a fixing unit 17, a sensor unit 55, It is mainly composed of an operation display unit 56. The system control unit 51 has a microcomputer configuration including at least a CPU, a ROM, and a RAM. The CPU controls the above-described units and the entire operation while using the RAM as a work area in accordance with a program stored in the ROM. The RAM also stores various data used by the CPU in the process.
[0081]
Image data for forming an image is input to the image input unit 52 via the scanner (original reading unit) 5 or a network. The image data input from the scanner 5 is subjected to image processing by the image processing unit 53 and then stored in the storage unit 54 or directly written into the light from the writing unit 15. When data subjected to image processing such as facsimile is input, the data is stored in the storage unit 54 without being subjected to image processing by the image processing unit 53, or optical writing is performed from the writing unit 15. In the image forming unit 2, optical writing is performed, and toner development is performed on the photoconductor 11 on which the latent image is formed as described above to form a visible image to be transferred. The developed image is transferred onto the sheet 6 conveyed via the sheet feeding unit 3, fixed by the fixing unit 17, and then discharged.
[0082]
The sensor unit 55 includes various sensors such as a sensor for detecting a conveyance state (jam) of the sheet 6 and a sensor for detecting the density of a developed image on the photoreceptor 11, and transmits the detected information to the system control unit 51. Send to In addition, the transmission type optical sensor 44 for detecting the paper type is also included in the sensor unit 55. The operation display unit 56 is for the user to input desired image forming conditions such as various modes, the number of copies, paper processing, paper type, and the like. The operation display unit 56 is the main body of the color image forming apparatus, here, the housing of the image forming unit 2. It is provided on the upper part of. The operation display unit 56 includes a touch panel type input device in addition to the key input device, and displays various setting conditions including a display of setting conditions input by a liquid crystal display device behind the touch panel and a warning display when the setting conditions are not met. Display is performed.
[0083]
As described above, the paper type detection means is constituted by, for example, the transmission type optical sensor 44, and determines the paper type of the paper 6 based on a difference in reflectance. The reflectance is measured in advance according to the type of paper, stored in the storage unit 54 as a table, and detected based on the output of the transmitted light from the transmission optical sensor 44.
[0084]
In the present embodiment, as the paper 6 usable through the paper feed cassettes 4a to 4d and the manual feed tray 8, for example, paper types such as plain paper, the second original drawing, and OHP paper are assumed. , Thick paper 1 and thick paper 2 are assumed to be used. Regarding the paper type including such a paper thickness, the transmittance of various types of paper detected by the transmission type optical sensor 44 shows a numerical example such as a correspondence table 57 shown in FIG. 5, and in the present embodiment, As an example, according to the range of the transmittance to be detected,
0.10 to 0.33: plain paper cardboard 2
0.33 to 0.40: plain paper cardboard 1
0.40 to 1.00: Medium thick cardboard plain paper
1.0 to 20: 2nd original drawing
20 to 90: OHP paper
Is set to be detected as
[0085]
Further, in the present embodiment, the fixing temperature of the fixing unit 17, the image forming speed (process speed) mm / s of the image forming unit 2, or the image forming condition is determined according to the paper type (including the paper thickness) of the paper 6. The transfer current μA is variably set and the image forming process is executed under the conditions suitable for each paper type. The appropriate conditions corresponding to these paper types are also defined on the correspondence table 57. I have. That is, regarding the fixing temperature,
Plain cardboard 1: 2,160 ° C
Medium thick plain paper: 150 ° C
2nd original drawing: 145 ° C
OHP paper: 155 ° C
Is defined as
Plain cardboard 1: 2,150mm / s
Plain medium cardboard & 2nd original drawing: 300mm / s
OHP paper: 100 mm / s
The transfer current is defined as
Plain paper cardboard 2: 24 μA
Plain cardboard 1: 22μA
Medium thick plain paper: 20μA
2nd original drawing: 19μA
OHP paper: 18μA
Is defined as
[0086]
When the transmittance detected by the transmission type optical sensor 44 is out of the range specified in the correspondence table 57, for example, when the transmittance is less than 0.1%, the paper is multi-feed or out of specification. It is determined that a detection operation error has occurred, and if the transmittance is greater than 90%, it is determined that there is no paper or a failure has occurred and a detection operation error has occurred.
[0087]
Although the transfer current is represented as the image forming condition, in practice, each voltage, current, and current applied to the photoconductor 11, the charging device 12, the developing device 13, the intermediate transfer belt 9, and the transfer device 16 are used. There are conditions such as frequency.
[0088]
In such a configuration, for example, in a case where the fixing temperature is variably set according to the paper type, an operation control example for detecting the paper type of the paper 6 will be described with reference to a schematic flowchart shown in FIG. This processing is executed by the CPU according to the control program stored in the ROM in the system control unit 51 while using the RAM as a work area (the same applies to the processing in the subsequent flowcharts).
[0089]
The operation control shown in FIG. 6 is a process individually performed for each of the paper feed cassettes 4a to 4d and the manual feed tray 8, and will be described as an example of the paper feed cassette 4a. First, when the image forming operation is performed by feeding the paper 6 from the paper feed cassette 4a based on the preceding paper feed command, it is determined whether or not the paper feed operation has been completed (step S1). When the operation is completed (Y in S1), the pickup roller 22 and the rollers 23, 24 for the paper feed cassette 4a are immediately driven by a predetermined amount as a timing until the next paper feed command is issued. Then, as shown in FIG. 3, the leading end of one uppermost sheet (the next sheet) 6 is pulled out and fed by a predetermined amount so as to reach the transmission type optical sensor 44, and then temporarily stopped (S2). ). In this state, the light emitting element 42 emits light, and the detection output of the transmission type optical sensor 44 is taken in, thereby detecting the transmittance of the next sheet 6 (S3). In this detection processing, if the transmittance is out of the specified range, it is processed as an error (not shown). By searching the correspondence table 57 using the detected transmittance, the paper type of the next paper 6 is determined (S4), and the resulting paper type information is made to correspond to the paper cassette 4a. It is stored in the storage unit 54 (S5). The processing of steps S1 to S5 is executed as a paper type detection operation or a paper type information acquisition operation for the next paper 6. In particular, the processing of steps S1 to S3 is executed as the function of the paper type detection paper feed timing control means, the paper type detection paper feed step, or the paper type information acquisition step.
[0090]
After detecting and acquiring the paper type information on the next paper 6 in this way, it is determined whether or not there is a paper supply schedule for the next paper 6 (S6). If there is an image forming operation request from the user through the operation display section 56 or from outside, the sheet feeding cassette 4a is designated, it is determined that there is a sheet feeding schedule (Y in S6), and there is no such request, or If the paper cassettes 4b to 4d are designated, it is determined that there is no paper feed schedule (N in S6). If there is no paper feeding schedule (N in S6), the process stands by until a paper feeding command is received.
[0091]
On the other hand, if there is a paper supply schedule (Y in S6), the appropriate fixing temperature range is set to the fixing unit 17 from the correspondence table 57 based on the paper type information on the next sheet 6 acquired and stored in the storage unit 54. The fixing temperature is variably set (S7), and the fixing temperature is controlled until the temperature of the fixing heater in the fixing roller in the fixing unit 17 falls within the set range (Y in S8 and S9). The processing of steps S7 to S9 is executed as a function of the fixing temperature setting unit.
[0092]
When the temperature of the fixing heater falls within the set range (Y in S9), and when other preparations (for example, setting of a transfer current to be described later) are completed (Y in S10), the roller 23 for the sheet cassette 4a is set. , 24 to drive these rollers 23, 24 to convey the next sheet 6 to the intermediate transfer belt 9 side via the registration rollers 20, etc. (S11). The image is formed in the forming unit 2 (S12). The processing of Y and S11 in step S10 is executed as a paper feeding and conveying step. After that, the process returns to step S1.
[0093]
Similar operation control is performed for the other paper feed cassettes 4 b to 4 d and the paper 6 on the manual feed tray 8.
[0094]
In the case of an example in which the image forming speed of the image forming unit 2 is variably set according to the paper type, as shown in FIG. 7, instead of the processing of steps S7 to S9, the acquired and stored in the storage unit 54 The appropriate image forming speed may be variably set for the image forming unit 2 from the correspondence table 57 based on the stored paper type information on the next paper 6 (S21). The process of step S21 is executed as a function of the process speed setting means.
[0095]
After that, when other preparations (for example, setting of the above-described fixing temperature, setting of a transfer current to be described later, etc.) are completed (Y in S10), the drum motor and the like in the image forming unit 2 are driven corresponding to the image forming speed. An image forming operation is started (S22), and immediately before this, an original paper supply command is issued to the rollers 23, 24 for the paper supply cassette 4a to drive these rollers 23, 24, The next sheet 6 is conveyed to the intermediate transfer belt 9 side via the registration rollers 20 and the like (S11), and is used for image formation in the image forming unit 2 (S12). The processing of Y and S11 in step S10 is executed as a paper feeding and conveying step. After that, the process returns to step S1.
[0096]
Further, in the case of an example in which the image forming condition of the image forming unit 2 is variably set according to the paper type, as shown in FIG. 8, instead of the processing of steps S7 to S9, the acquired and stored in the storage unit 54 An appropriate image forming condition may be variably set for the image forming unit 2 from the correspondence table 57 based on the stored paper type information on the next sheet 6 (S23). In this example, the transfer current is variably set as the image forming condition. According to the variable setting, the control of the image forming conditions is performed until the control of the image forming conditions is completed (Y in S24 and S25). The processing of steps S23 to S25 is executed as a function of the image forming condition setting means.
[0097]
When the control of the image forming conditions is completed (Y in S25), and other preparations (for example, the setting and control of the fixing temperature described above) are completed (Y in S10), the rollers 23 and 24 for the sheet feeding cassette 4a are used. Then, the original paper feed command is issued to drive these rollers 23 and 24, and the next paper 6 is conveyed to the intermediate transfer belt 9 side via the registration rollers 20 and the like (S11), whereby the image forming unit (S12). The processing of Y and S11 in step S10 is executed as a paper feeding and conveying step. After that, the process returns to step S1.
[0098]
That is, in the case of the operation control example shown in FIG. 6, FIG. 7, or FIG. 8, every time the paper 6 is fed for image formation, the paper type detection for the next paper 6 is performed at a timing prior to the paper feed command. Thus, for example, even when sheets 6 of different paper types are mixedly loaded in the paper feed cassette 4a, the paper type can be acquired for each sheet in advance and reflected in the image forming process. Therefore, appropriate measures can be taken in accordance with the type of each of the loaded sheets 6. In addition, since the paper type information can be automatically acquired before the paper supply instruction for the next paper 6 is actually issued, the paper type information can be automatically acquired by the image forming unit 2 before the paper supply instruction is received. Appropriate settings that can be used effectively and reliably can be made, and waste of time and energy can be eliminated in the image forming process. In particular, in the case of the tandem type full-color image forming apparatus as in the present embodiment, the image forming operation is already started at the time of paper feeding, but since the paper type information of the paper 6 is known in advance, the paper type information is There is no need to re-form an image as in the case where the image is recognized later, and it is possible to eliminate waste of time and energy involved in the re-formation.
[0099]
[Another embodiment of paper type detection operation timing]
Here, another example of the operation timing for detecting the type of the sheet 6 and an example of the accompanying operation control will be described with reference to FIGS. 9 and 10. In this example, when the power of the full-color image forming apparatus is turned on (Y in S31), the pickup roller 22 and the rollers 23 and 24 for the sheet cassette 4a are immediately set as an example of a timing prior to the sheet feeding command. By driving a predetermined amount, the leading end of one uppermost sheet 6 is pulled out and fed by a predetermined amount to reach the transmission type optical sensor 44 as shown in FIG. 3, and then temporarily stopped there (S32). In this state, the transmittance of the paper 6 is detected by causing the light emitting element 42 to emit light and taking in the detection output of the transmission optical sensor 44 (S33). In this detection processing, if the transmittance is out of the specified range, it is processed as an error (not shown). By searching the correspondence table 57 using the detected transmittance, the paper type of the paper 6 is determined (S34), and the resulting paper type information is stored in the storage unit in association with the paper cassette 4a. 54 (S35). Such paper type information detection / acquisition processing is similarly performed for the other paper feed cassettes 4b to 4d and the manual feed tray 8 in that order (S36). The processing of steps S31 to S36 is executed as a paper type detection operation or paper type information acquisition operation for the paper 6 of each unit when the power is turned on. In particular, the processing of steps S31 to S33 is executed as the function of the paper type detection paper supply timing control means, the paper type detection paper supply step, or the paper type information acquisition step.
[0100]
Further, after the power is turned on, at any time thereafter, it is monitored whether or not any of the paper feed cassettes 4a to 4d has been pulled out and stored (S41). If a pull-out / storing operation has been performed on the paper cassette (Y in S41), it is considered that a new loading of the paper 6 has been performed on the paper cassette, and the pickup roller 22 and the roller for the paper cassette have been loaded. By driving the sheets 23 and 24 by a predetermined amount, the leading end of one uppermost sheet 6 is drawn out and fed by a predetermined amount so as to reach the transmission type optical sensor 44 as shown in FIG. 3, and then temporarily stopped there. (S42). In this state, the light emitting element 42 emits light and the detection output of the transmission type optical sensor 44 is taken in, thereby detecting the transmittance of the paper 6 (S43). In this detection processing, if the transmittance is out of the specified range, it is processed as an error (not shown). By searching the correspondence table 57 using the detected transmittance, the paper type of the paper 6 is determined (S44), and the resulting paper type information is stored in the storage unit 54 in association with the paper cassette. It is stored inside (S45).
[0101]
In other words, according to the operation timing example shown in FIG. 9, at least when the power of the full-color image forming apparatus is turned on, the paper type detection operation of the paper 6 stored in each unit is performed. Even if the paper type is changed, it is possible to take appropriate measures according to the paper type. Further, since the paper type is changed by loading the paper 6 into the paper feed cassettes 4a to 4d and the manual feed tray 8, the paper 6 is loaded into the paper feed cassettes 4a to 4d and the manual feed tray 8. At times, by performing the paper type detection operation of the paper 6, it is possible to reliably cope with the change of the paper type, and to appropriately respond to the paper type of the paper loaded in the paper feed cassettes 4 a to 4 d or the manual feed tray 8. Becomes possible. Here, as an actual control example, whether or not new paper 6 has been loaded can be determined by using a paper end sensor or the like. In the case of a paper feed cassette, the presence or absence of the pull-out / storing operation is used. It is easy and reliable. That is, when the paper storage units are the paper feed cassettes 4a to 4d, the pull-out / storage operation of the paper feed cassettes 4a to 4d may be performed during a jam processing or the like. Since the draw-out / storing operation of the cassettes 4a to 4d is performed, when the pull-out / storing operation of the paper feed cassettes 4a to 4d is performed, the paper type detecting operation of the paper 6 is performed, so that the new paper 6 is loaded. Can be surely dealt with due to the change of the paper type associated with the paper feed cassettes 4a to 4d.
[0102]
By the way, an example of operation control of the image forming process when the paper type is detected and acquired in such an operation timing example will be described with reference to a schematic flowchart shown in FIG. The example shown in FIG. 10 is a control example of the fixing temperature corresponding to FIG. First, the process waits until there is an image forming operation request from the user through the operation display unit 56 or from outside (S51). If there is an image forming request (Y in S51), the user receives a designation of a paper feeding place in the request (which Whether paper should be fed from the paper feed cassettes 4a to 4d or the manual feed tray 8) (S52), and the paper type information of the paper 6 stored in the storage unit 54 corresponding to the specified paper feed location is read (S53). . Then, an appropriate fixing temperature range is variably set for the fixing unit 17 from the correspondence table 57 based on the read paper type information (S54), and the temperature of the fixing heater in the fixing roller in the fixing unit 17 is set to the setting range. The fixing temperature control is performed until the value is within (Y in S55 and S56). The processing of steps S54 to S56 is executed as a function of the fixing temperature setting unit.
[0103]
If the temperature of the fixing heater falls within the set range (Y in S56), and if other preparations (for example, setting of the transfer current, etc.) are completed (Y in S57), the designated roller 23 for the paper feeding place is set. , 24 to drive these rollers 23, 24 to convey the paper 6 to the intermediate transfer belt 9 side through the registration rollers 20 and the like (S58), whereby the image forming unit 2 (S59). The processing of Y and S58 in step S57 is executed as a paper feeding and transporting step.
[0104]
The same applies to the case where the image forming speed and the transfer current are variably set. During the process control shown in FIG. 10, the image forming speed setting and the transfer current (image forming condition setting) as shown in FIGS. And the like are only applied, and illustration and description are omitted.
[0105]
[Another Embodiment Regarding Feed Control]
Next, an example of paper supply control of the paper 6 used in the paper type detection operation will be described as another embodiment with reference to FIG. In FIG. 11, an example of the sheet cassette 4a will be described, but the same applies to the sheet cassettes 4b to 4d. As described above, when the paper type is detected, the paper 6 is fed by a predetermined amount up to the position where the transmission type optical sensor 44 is reached at a timing prior to the paper feed command. If the sheet cassette 4a is left as it is, the sheet cassette 4a can be pulled out from the apparatus main body. Therefore, if the sheet cassette 4a is pulled out, the sheet 6 sandwiched between the rollers 23 and 24 may be damaged. There is. Therefore, here, the sheet cassette 4a is pulled out after the sheet 6 is fed by a predetermined amount to a position where the sheet 6 reaches the position of the transmissive optical sensor 44 and subjected to the above-described sheet type detection operation. The paper 6 is pulled back into the paper feed cassette 4a by a pull-back means.
[0106]
FIG. 11 shows an example in which the FRR type separation sheet feeding means 25 is used as it is as a pullback means. First, a normal feeding operation will be described with reference to FIG. The separation sheet feeding means 25 is a feeding method called an FRR method, and the uppermost sheet 6 is fed between the sheet feeding roller 23 and the reverse roller 24 when the pickup roller 22 rotates counterclockwise. Here, the drive is performed so that both the paper feed roller 23 and the reverse roller 24 rotate counterclockwise. The reverse roller 24 has a built-in torque limiter (not shown), and When there is no paper, and when there is only one sheet 6, the paper 6 rotates together with the paper feed roller 23 (rotates clockwise). On the other hand, when there are a plurality of sheets 6, the sheet 6 is rotated counterclockwise as shown in FIG. 11B, and the sheets 6 other than the top one sheet 6 are pulled back. As a result, only one sheet 6 is removed. Feed separately. Thereafter, as shown in FIG. 3, the paper is fed to the position of the transmission type optical sensor 44, and is used for detecting the paper type.
[0107]
Here, in this alternative embodiment, when the paper type detection operation is completed, as shown in FIG. 11C, the pickup roller 22 and the paper feed roller 23 are rotated in the reverse direction (clockwise), and the paper 6 is moved. Pull it back into the paper feed cassette 4a. At this time, the reverse roller 24 may rotate counterclockwise as in the case of feeding, or may be separated from the sheet feeding roller 23 as shown in FIG. In the case where the reverse roller 24 is separated from the paper feed roller 23, the reverse roller 24 may be rotated in any direction or not.
[0108]
The rotation direction of the paper feed roller 23 and the like can be easily switched using a stepping motor, but other methods may be used.
[0109]
Therefore, in the case of the paper cassettes 4a to 4d that can be pulled out, if a predetermined amount of the paper 6 is kept to be fed for detecting the paper type, the paper cassettes 4a to 4d are pulled out with this operation. Although the paper 6 is damaged, the paper 6 is pulled back into the paper feed cassettes 4a to 4d after the detection of the paper type, thereby preventing the paper 6 from being damaged due to the operation of pulling out the paper feed cassettes 4a to 4d. .
[0110]
In this case, after the paper 6 is fed by a predetermined amount by the separation feeding unit 25 and used for paper type detection, until the paper 6 is pulled back in the paper feed cassettes 4a to 4d, the system control unit 51 It is desirable that the CPU warn the prohibition of the pull-out operation of the sheet cassette through the display unit of the operation display unit 56 (warning means). That is, if the paper feed cassettes 4a to 4d are pulled out before the paper 6 is pulled back, there is a possibility that the papers will be damaged. By calling attention, it is possible to prevent the paper from being damaged due to the drawing operation of the paper feed cassette. The warning may be issued by lighting a warning lamp provided directly on the paper cassette or the like.
[0111]
[Another embodiment associated with paper feed control]
An example of the configuration around the paper feed cassette associated with the paper feed control of the paper 6 used in the paper type detection operation will be described as another embodiment with reference to FIG. FIG. 12 illustrates an example of the sheet cassette 4a, but the same applies to the sheet cassettes 4b to 4d.
[0112]
In the present embodiment, a lock means 61 for inhibiting the pull-out operation is added to the sheet cassette 4a which can be pulled out and stored in the apparatus main body 1. The lock means 61 is provided in the apparatus main body 1 and is capable of engaging and disengaging from a locking concave portion 62 of the paper feed cassette 4a. The lock means 61 is provided rotatably about a fulcrum 64. A link 65 slidably held, a locking solenoid 67 having a plunger 66 connected to the lock pin 63 via the link 65, and a lock pin 63 provided on the plunger 66 and locking the lock pin 63 via the link 65. It is constituted by a lock release spring 68 which is urged in a direction away from the concave portion 62. The solenoid 67 is one of the driving sources included in the sheet feeding unit 3, and is controlled to be energized by a CPU in the system control unit 51.
[0113]
That is, normally, the solenoid 67 is not energized and the lock pin 63 is kept out of the locking recess 62 as shown in FIG. 12A by the urging force of the lock release spring 68, and the paper feed cassette 4a is pulled out.・ It is in a state where it can be stored.
[0114]
On the other hand, after the paper 6 is fed by a predetermined amount by the separation paper feeding means 25 and used for paper type detection, and until the paper 6 is pulled back in the paper feed cassettes 4a to 4d, the CPU of the system control unit 51 Thus, the energization control for the solenoid 67 is performed. As a result, as shown in FIG. 12B, the plunger 66 is sucked against the unlocking spring 68, so that the lock pin 63 is slid and displaced in the state of being locked in the locking concave portion 62, and the paper is fed. The cassette 4a is locked so that it cannot be pulled out. Accordingly, the sheet feeding cassette 4a cannot be pulled out while the sheet 6 is pulled out and fed by a predetermined amount, so that the sheet 6 can be reliably prevented from being damaged. When the pulling-back process of the sheet 6 is completed, the power supply to the solenoid 67 is released, and the sheet cassette 4a is returned to a state where it can be pulled out.
[0115]
Therefore, as described above, if the sheet cassette 4a is pulled out before the sheet 6 is pulled back, the sheet 6 may be damaged. , The breakage of the sheet 6 due to the pulling-out operation of the sheet cassette 4a can be reliably prevented.
[0116]
[Still Another Embodiment Accompanying Paper Feed Control]
Referring to FIGS. 13 and 14, another example of the configuration around the paper feed cassette associated with the paper feed control of the paper 6 used in the paper type detection operation will be described. 13 and 14, an example of the sheet cassette 4a will be described, but the same applies to the sheet cassettes 4b to 4d.
[0117]
In the present embodiment, the sheet 6 retraction means 71 for the sheet cassette 4a which can be freely pulled out and stored in the apparatus main body 1 is used to move the sheet 6 in conjunction with the drawing operation of the sheet cassette 4a. It is configured to include an interlocking mechanism 72 for pulling it back inside. The interlocking mechanism 72 includes an arm 74 that is rotatably held in a horizontal plane around a support shaft 73 at the back of the storage position of the paper feed cassette 4a and extends to the front of the paper feed side position of the paper feed cassette 4a. The pin 75, which is integrally provided near the tip of the arm 74 and can interfere with the paper 6 fed by a predetermined amount from the paper feed cassette 4a in the rotation locus of the arm 74, and the arm 74 in plan view. A spring 76 that urges in a clockwise direction (retraction direction by the pin 75) and an arm 74 (accordingly, the pin 75) are brought into contact with a part of the sheet cassette 4a formed in a part of the arm 74 and stored. The convex portion 77 regulates the standby position. An arc-shaped slit 79 that escapes the pin 75 is formed in a guide plate 78 provided in front of the paper feed cassette 4a on the paper feed side. Further, the retraction unit 71 of the present embodiment includes such an interlocking mechanism 72 and a control unit for selectively separating the reverse roller 24 from the sheet feeding roller 23.
[0118]
FIG. 13 shows a state in which the paper feed cassette 4a is located at the storage position and the paper 6 in the paper feed cassette 4a is fed to a position where the paper type can be detected by the transmission type optical sensor 44. Is shown. At this time, since the convex portion 77 is in contact with the paper feed cassette 4a, the tip end of the arm 74 is regulated to the front position of the paper feed cassette 4a against the spring 76, and the pin 75 is located at the standby position. I have.
[0119]
When the paper feed cassette 4a is pulled out from such a state, as shown in FIG. 14, the projection 77 separates from the paper feed cassette 4a, and the arm 74 is in a free state. It is displaced clockwise around 73. With the rotational displacement of the arm 74, the pin 75 on the tip side also moves toward the paper feed cassette 4a and interferes with the paper 6 that has been fed by a predetermined amount in its movement trajectory. Pull it back into the paper cassette 4a. During the operation of pulling out the paper feed cassette 4a, the reverse roller 24 separates from the paper feed roller 23, and the operation of pulling back the paper 6 by the pin 75 is performed smoothly.
[0120]
Therefore, as described above, if the paper feed cassette 4a is pulled out before the paper 6 is pulled back, the paper 6 may be damaged. However, by using the pull-back means 71 having the interlocking mechanism 72, Since the paper 6 is pulled back into the paper feed cassette 4a in conjunction with the pull-out operation of the paper feed cassette 4a, the paper 6 associated with the pull-out operation of the paper feed cassette 4a is not restricted without restricting the pull-out operation of the paper feed cassette 4a. Can be reliably prevented.
[0121]
[Another Embodiment Regarding Paper Feeder]
An example of the configuration around the paper feed cassette in the paper feeder associated with the paper feed control for the paper 6 used in the paper type detection operation will be described as still another embodiment with reference to FIG. In FIG. 15, an example of the sheet cassette 4a will be described, but the same applies to the sheet cassettes 4b to 4d.
[0122]
In the present embodiment, the rollers 22, 23, and 24 and the transmission type optical sensor 44 are integrally supported by the support arm 81 and the like with respect to the sheet cassette 4a that can be pulled out and stored in the apparatus main body 1. I have. The support arm 81 has a structure in which a clearance groove 82 for feeding the sheet 6 is formed.
[0123]
Therefore, as described above, even if the paper 6 is kept fed by a predetermined amount for detecting the paper type, the rollers 22, 23, 24 and the transmission light Since the sensor 44 is also integrally pulled out, it is possible to reliably prevent the paper 6 from being damaged due to the pulling-out operation of the paper feed cassette 4a without restricting the pull-out operation of the paper feed cassette 4a. In addition, since the pull-back operation of the paper 6 is not required, the control is simplified, the paper can be fed to the image forming unit 2 as it is, and the processing can be speeded up.
[0124]
As shown in FIG. 16, the support arm 81 and the relief groove 82 may be provided on the drawer side of the sheet cassette 4a.
[0125]
[Various modifications]
Although the present embodiment has been described as an example of application to a tandem type full-color image forming apparatus (multifunction peripheral), the present invention is not limited to the tandem type and can be applied. In addition, the present invention is not limited to color, and can be similarly applied to a monochrome image forming apparatus, and may be a printer alone, a copying machine, a facsimile machine, or the like. Further, the invention is not limited to the image forming apparatus using the electrophotographic process, and may be, for example, an ink jet printer. In the case of an ink jet printer, the process speed may be variably set according to the paper type information, or the amount of ink may be variably set as an image forming condition.
[0126]
Further, although the example using the transmission type optical sensor 44 as the paper type detecting means has been described, other various types of detecting means can be used.
[0127]
For example, the method of detecting the paper type of the paper 6 in a non-contact manner by using an optical measurement method is not limited to the transmission type optical sensor 44, and for example, a reflection type light as shown in FIG. A sensor may be used. Alternatively, a reflection type optical sensor using a combination of an LED light source and an optical distance sensor (PSD) as shown in FIG. 11 of Patent Document 4 may be used. Further, as shown in FIG. 1 of Patent Document 4 and the like, a paper type detecting means for detecting a paper type by converting a mechanical displacement amount into an electric signal may be used, or FIG. As shown in the figure, a paper type detection unit that detects the paper type using a capacitance sensor that detects the capacitance of an air capacitor that measures the capacitance of the paper may be used. Various methods other than the methods exemplified here can be used.
[0128]
【The invention's effect】
According to the first aspect of the present invention, at a timing prior to the paper feed instruction, the leading end of one sheet is fed from the paper storage unit by the separate paper feed unit by a predetermined amount, and the paper type detection unit detects the leading end of the sheet. Since the paper type is detected and the paper type information is obtained before receiving the paper feed command, the paper type information is effectively and reliably used in the image forming process of the image forming means before receiving the paper feed command. Settings can be made, and waste of time and energy can be eliminated in the image forming process.
[0129]
According to the second aspect of the present invention, as the paper type information, in addition to the general paper thickness in this type of image forming apparatus, the distinction between plain paper, OHP paper, and the second original drawing can be handled. Such paper type information can be used for improving image quality and the like. Particularly, regarding the paper thickness, since only one paper is separated and fed and detected by the paper type detecting means, it is possible to obtain reliable information.
[0130]
According to the third aspect of the invention, in the image forming apparatus according to the first or second aspect, only one sheet is separated and fed, and the sheet type such as the sheet thickness is detected. Can be reliably and easily detected by a general non-contact method using an optical measurement method.
[0131]
According to the fourth aspect of the present invention, in the image forming apparatus according to the third aspect, only one sheet is separated and fed, and the sheet type such as the sheet thickness is detected. Detection can be reliably and easily performed by a dynamic measurement method, particularly a method using a transmission type optical sensor.
[0132]
According to the fifth aspect of the present invention, in the image forming apparatus according to the first or second aspect, only one sheet is separated and fed, and the sheet type such as the sheet thickness is detected. Can be reliably and easily detected by a general method using a mechanical displacement method of converting a mechanical displacement amount into an electric signal.
[0133]
According to the sixth aspect of the present invention, in the image forming apparatus according to the first or second aspect, only one sheet is separated and fed, and the sheet type such as the sheet thickness is detected. Can be reliably and easily detected by a general non-contact method using a capacitance sensor.
[0134]
According to the seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects, since a plurality of paper storage units are provided with paper type detection means individually for each paper storage unit, The paper type information of the paper held in the paper storage unit can be acquired without omission, and appropriate image forming process control according to the paper type information can be performed.
[0135]
According to the eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, at least when the power of the image forming apparatus is turned on, the paper type detecting operation is performed, Even if the paper type is changed before the power is turned on, it is possible to take appropriate measures according to the paper type.
[0136]
According to the ninth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, the change of the paper type is performed when the paper is loaded into the paper storage unit. When the paper is loaded, the paper type detection operation is performed, so that the change of the paper type can be dealt with reliably, and the appropriate response according to the paper type of the paper loaded in the paper storage unit Becomes possible.
[0137]
According to the tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, when the paper storage unit is a paper supply cassette, the operation of pulling out and storing the paper supply cassette may be at the time of jam clearance or the like. When a new sheet is loaded, the operation of pulling out and storing the sheet cassette is always performed, so that it is possible to reliably cope with a change in the sheet type accompanying the loading of a new sheet. It is possible to take appropriate measures according to the type of paper.
[0138]
According to an eleventh aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, each time a sheet is fed for image formation, a paper type detection for the next sheet is performed. Thus, for example, even when sheets of different paper types are mixed in the paper storage unit, the paper type can be acquired for each sheet in advance, and the paper of each loaded paper sheet can be obtained. Appropriate measures can be taken according to the species.
[0139]
According to the twelfth aspect of the present invention, in the image forming apparatus according to any one of the first to eleventh aspects, in the case of a paper cassette which can be pulled out, a predetermined amount of paper is fed to detect a paper type. If the paper cassette is left as it is, this paper may be damaged by the operation of pulling out the paper cassette. However, after the paper type is detected, the paper is pulled back into the paper cassette so that the paper cassette can be pulled out. Can be prevented from being damaged.
[0140]
According to the thirteenth aspect of the present invention, in realizing the invention of the twelfth aspect, if the sheet cassette is pulled out before the sheet is pulled back, the sheet may be damaged. By warning that the drawer operation of the cassette is prohibited and alerting the operator, it is possible to prevent the paper from being damaged due to the drawer operation of the sheet cassette.
[0141]
According to the fourteenth aspect of the present invention, in realizing the invention of the twelfth aspect, if the sheet cassette is pulled out before the sheet is pulled back, the sheet may be damaged. In addition, by forcibly prohibiting the drawing operation of the sheet cassette by the lock means, it is possible to reliably prevent the paper from being damaged due to the drawing operation of the sheet cassette.
[0142]
According to the fifteenth aspect of the present invention, in realizing the twelfth aspect of the invention, if the sheet cassette is pulled out before the sheet is pulled back, the sheet may be damaged. Is used, the paper is pulled back into the paper feed cassette in conjunction with the pull-out operation of the paper feed cassette, so that the paper with the pull-out operation of the paper feed cassette is not restricted without restricting the pull-out operation of the paper feed cassette. Can be reliably prevented.
[0143]
According to a sixteenth aspect of the present invention, in the image forming apparatus according to any one of the first to eleventh aspects, when the paper storage unit includes a paper supply cassette, the paper supply cassette is separated from the paper supply unit by a paper supply unit. The detection means is integrated so that it can be pulled out and stored in the main body of the image forming apparatus, so that a predetermined amount of paper can be supplied for detecting the paper type. Since the separating paper feeding means and the paper type detecting means are also integrally pulled out with the operation of pulling out the paper cassette, the breakage of the paper due to the pulling out operation of the paper feeding cassette can be reliably performed without restricting the pulling out operation of the paper feeding cassette. Can be prevented. In addition, since the sheet pull-back operation is not required, the control is simplified, the sheet can be fed to the image forming unit, and the processing speed can be increased.
[0144]
According to the seventeenth aspect of the invention, in the image forming apparatus according to any one of the first to sixteenth aspects, in the case of an electrophotographic image forming unit, a fixing device is provided, After the fixing temperature is variably set in accordance with the acquired paper type information, the paper is actually fed and conveyed, so that there is no need to reset the fixing temperature and the like, the time required for resetting the fixing temperature, Energy can be wasted.
[0145]
According to the eighteenth aspect of the present invention, in the image forming apparatus according to any one of the first to sixteenth aspects, the process speed of the image forming unit is different from the proper speed depending on the type of paper, but the timing prior to the paper feed command is not changed. By setting the process speed variably in accordance with the paper type information acquired in advance, the paper is actually fed and conveyed, so that there is no need to re-form the image, etc. Can be eliminated.
[0146]
According to the nineteenth aspect of the present invention, in the image forming apparatus according to any one of the first to sixteenth aspects, the image forming conditions of the image forming means, for example, the transfer current and the like vary depending on the type of paper. By setting the image forming conditions variably according to the paper type information acquired in advance at a timing prior to the paper feed command, the paper is actually fed and conveyed, so that there is no need to re-form the image and the like. It is possible to eliminate the waste of time and energy required for reworking.
[0147]
According to the twentieth aspect, it is possible to provide a sheet feeding device suitable for application to the image forming apparatus according to the first to twelfth aspects.
[0148]
According to the twenty-first aspect, it is possible to provide a sheet feeding device suitable for application to the image forming apparatus according to the sixteenth aspect.
[0149]
According to the invention described in claim 22, at the timing prior to the paper feed command, the leading end of one paper is fed from the paper storage unit by the separate paper feed unit by a predetermined amount, and the paper type detection unit detects the leading end of the paper. By detecting the paper type, it is possible to obtain the paper type information before receiving the paper feed command, so that the paper type information can be used effectively and reliably for the image forming process of the image forming means before receiving the paper feed command. Settings can be made, and waste of time and energy can be eliminated in the image forming process.
[0150]
According to the twenty-third aspect of the present invention, the paper type detection operation is performed at least when the power of the image forming apparatus is turned on. It is possible to take appropriate measures according to the situation.
[0151]
According to the twenty-fourth aspect, the change of the paper type is performed when the paper is loaded into the paper storage unit. Therefore, when the paper is loaded into the paper storage unit, the paper type detection operation of the paper is performed. By doing so, it is possible to reliably cope with the change of the paper type, and it is possible to appropriately cope with the paper type of the paper loaded in the paper storage unit.
[0152]
According to the twenty-fifth aspect of the present invention, when the paper storage unit is a paper feed cassette, the paper cassette may be pulled out and stored at the time of jam clearance or the like. By performing the operation of pulling out and storing the paper cassette, it is possible to reliably cope with a change in the paper type accompanying the loading of new paper, and to take appropriate measures according to the paper type of the paper loaded in the paper cassette. It becomes possible.
[0153]
According to the twenty-sixth aspect of the invention, each time a sheet is fed for image formation, the sheet type of the next sheet is detected, so that, for example, sheets of different types are mixed and loaded in the sheet storage unit. Even in such a case, the paper type can be acquired for each sheet in advance, and appropriate measures can be taken according to the paper type of each loaded paper.
[0154]
According to the twenty-seventh aspect of the present invention, in the case of a paper cassette which can be pulled out, if a predetermined amount of paper is kept fed for the paper type detection, the paper cassette is pulled out. Although the sheet may be damaged, the sheet is pulled back into the sheet cassette after detecting the sheet type, thereby preventing the sheet from being damaged due to the operation of pulling out the sheet cassette.
[0155]
According to the twenty-eighth aspect of the present invention, in the case of the electrophotographic image forming means, a fixing device is provided, but after the fixing temperature is variably set according to the paper type information acquired in advance at a timing prior to the paper feed command. By actually feeding and transporting the paper, there is no need to reset the fixing temperature, and the time and energy involved in resetting the fixing temperature can be wasted.
[0156]
According to the twenty-ninth aspect, the process speed of the image forming unit varies depending on the paper type, but the process speed is variably set according to the paper type information obtained in advance at a timing prior to the paper feed command. By actually feeding and transporting the paper after this, there is no need to re-form the image, and it is possible to eliminate the time and energy waste associated with the re-formation.
[0157]
According to the thirty-first aspect of the present invention, the image forming conditions of the image forming means, for example, the transfer current and the like have different appropriate conditions depending on the paper type. By variably setting the image forming conditions in response to the actual paper feeding and conveyance, there is no need to re-form the image, and the time and energy associated with the re-formation can be eliminated.
[Brief description of the drawings]
FIG. 1 is a vertical sectional front view schematically showing an overall configuration of a full-color image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram schematically illustrating a configuration example of a paper feeding unit.
FIG. 3 is an enlarged schematic configuration diagram schematically illustrating an example of the configuration of a separation sheet feeding unit and a paper type detection unit;
FIG. 4 is a schematic configuration diagram illustrating a control system of the full-color image forming apparatus.
FIG. 5 is an explanatory diagram showing an example of data of a correspondence table.
FIG. 6 is a schematic flowchart illustrating an example of operation control.
FIG. 7 is a schematic flowchart illustrating an example of operation control in the case of an image forming speed variable setting.
FIG. 8 is a schematic flowchart illustrating an example of operation control in a case where image forming condition variable setting is performed.
FIG. 9 is a schematic flowchart showing another embodiment of the operation control example.
FIG. 10 is a schematic flowchart illustrating an operation control example of an image forming process.
FIG. 11 is a schematic front view illustrating an embodiment relating to an example of sheet feeding control of a sheet.
FIG. 12 is a schematic plan view showing an embodiment relating to a configuration example around a paper feed cassette.
FIG. 13 is a schematic plan view showing another embodiment relating to a configuration example around a sheet feeding cassette.
FIG. 14 is a schematic plan view showing a state in which the sheet cassette is pulled out.
FIG. 15 is a schematic perspective view showing an embodiment relating to a configuration example of a sheet feeding device.
FIG. 16 is a schematic perspective view showing a modification.
[Explanation of symbols]
1 Device body
2 Image forming means
3 paper feeder
4a-4d paper cassette; paper storage unit
6 paper
8 Paper storage section
25 Separate paper feeding means
41a-41d paper type detecting means
44 Transmission Optical Sensor
54 Memory
61 Locking means
71 Pullback means
72 Interlocking mechanism

Claims (30)

A paper storage unit for stacking and holding paper,
Separating sheet feeding means for separating and feeding the sheets one by one from the sheet storage unit;
Image forming means for forming an image on the sheet fed by the separation sheet feeding means,
Paper type detecting means for detecting a paper type including at least a paper thickness of the paper fed by the separation paper feeding means,
At a timing prior to a sheet feeding instruction, a sheet for causing a predetermined amount of the leading end of one sheet to be fed from the sheet storage unit by the separation sheet feeding unit and the sheet type of the sheet to be detected by the sheet type detecting unit. Feed timing control means for species detection;
An image forming apparatus comprising: The image forming apparatus according to claim 1, wherein the detected paper type information includes a distinction between plain paper, OHP paper, and the second original drawing in addition to the paper thickness. The image forming apparatus according to claim 1, wherein the paper type detection unit detects the paper type of the paper in a non-contact manner using an optical measurement method. The image forming apparatus according to claim 3, wherein the paper type detection unit detects the paper type using a transmission optical sensor that detects a transmittance of the paper. The image forming apparatus according to claim 1, wherein the paper type detection unit detects a paper type of the paper by converting a mechanical displacement amount into an electric signal. The image forming apparatus according to claim 1, wherein the paper type detection unit detects a paper type of the paper using a capacitance sensor that measures a capacitance of the paper. The image forming apparatus according to claim 1, wherein the image forming apparatus includes a plurality of the paper storage units, and the paper type detection unit is individually provided for each of the paper storage units. 8. The paper type detection paper feed timing control means, as a timing prior to a paper feed command, performs a paper type detection operation of the paper at least when the power of the image forming apparatus is turned on. An image forming apparatus according to any one of the preceding claims. 9. The sheet type detection sheet supply timing control means causes the sheet type detection operation of the sheet to be performed when the sheet is loaded into the sheet storage unit, as a timing prior to a sheet supply command. The image forming apparatus according to any one of the above. The paper storage unit includes a paper cassette that can be pulled out and stored in the image forming apparatus main body,
10. The image according to claim 9, wherein the sheet type detection sheet supply timing control unit causes the sheet type detection operation of the sheet to be performed each time the drawn-out sheet supply cassette is stored in the image forming apparatus main body. 11. Forming equipment. The paper type detection paper feed timing control means may feed the paper from the paper storage unit based on the preceding paper feed command until the next paper feed command is issued, as a timing preceding the paper feed command. The image forming apparatus according to any one of claims 1 to 8, wherein a sheet type detection operation of the sheet is performed for the sheet storage unit during the period. The paper storage unit includes a paper cassette that can be pulled out and stored in the image forming apparatus main body,
Storage means for storing the paper type information detected by the paper type detection means in a storage unit;
Pullback means for pulling the paper fed by a predetermined amount into the corresponding paper feed cassette after the paper type is detected by the paper type detection means,
The image forming apparatus according to claim 1, further comprising: A warning unit is provided for warning that the pull-out operation of the sheet cassette is prohibited after the predetermined amount of the sheet is fed by the separation sheet unit and until the sheet is pulled back into the sheet cassette by the pull-back unit. The image forming apparatus according to claim 12. 13. A lock unit for prohibiting an operation of pulling out the sheet feeding cassette from a time when the predetermined amount of the sheet is fed by the separation sheet feeding unit until the sheet is pulled back into the sheet feeding cassette by the pull-back unit. The image forming apparatus as described in the above. 13. The image forming apparatus according to claim 12, wherein the pulling-back unit has a link mechanism that pulls the paper back into the sheet cassette in conjunction with a pull-out operation of the sheet cassette. The paper storage unit includes a paper cassette that can be pulled out and stored in the image forming apparatus main body, and the paper cassette integrally includes the separation paper feeding unit and the paper type detection unit, and The image forming apparatus according to claim 1, wherein the image forming apparatus can be pulled out and stored in the forming apparatus main body. The image forming means forms an image by an electrophotographic method,
A fixing temperature setting unit that variably sets a fixing temperature according to the paper type information obtained by the detection of the paper type detection unit at a timing prior to the paper feeding instruction when a paper feeding command is received;
Paper feed transport control means for feeding and transporting the paper toward the image forming means after variably setting the fixing temperature,
The image forming apparatus according to claim 1, further comprising: A process speed setting unit configured to variably set a process speed of the image forming unit in accordance with the paper type information obtained by the detection of the paper type detection unit at a timing prior to the paper feeding instruction when a paper feeding instruction is received;
Paper feed control means for feeding and feeding the paper toward the image forming means after the variable setting of the process speed,
The image forming apparatus according to claim 1, further comprising: An image forming condition setting means for variably setting an image forming condition of the image forming means in accordance with the paper type information obtained by the detection of the paper type detecting means at a timing prior to the paper feeding instruction when a paper feeding instruction is received; When,
Paper feed control means for feeding the paper toward the image forming means after variably setting the image forming conditions,
The image forming apparatus according to claim 1, further comprising: A paper feed cassette that can be pulled out and stored in the image forming apparatus main body and that holds and stacks paper;
Separating sheet feeding means for separating and feeding the sheets one by one from the sheet cassette;
Paper type detection means for detecting a paper type including at least a paper thickness of the paper fed by the separation paper feeding means;
The leading end of one sheet is fed from the sheet cassette by the separation sheet feeding means by a predetermined amount, and the sheet subjected to the detection of the sheet type by the sheet type detecting means is pulled out of the sheet feeding cassette. Pull-back means having a link mechanism for pulling back into the paper feed cassette in conjunction with an operation,
A paper feeder comprising: A paper feed cassette that can be pulled out and stored in the image forming apparatus main body and that holds and stacks paper;
Separating paper feeding means integrated with the paper feeding cassette and separating and feeding the sheets one by one from the paper feeding cassette;
Paper type detecting means for detecting the paper type of the paper fed by the separation paper feeding means integrated with the paper feeding cassette;
A paper feeder comprising: Paper type information acquiring method used in an image forming method in which sheets stacked and held in a sheet storage unit are separated and fed one by one by a separating sheet feeding unit, and an image is formed on the fed sheet by an image forming unit. And
Using a paper type detection unit that detects a paper type including at least the thickness of the paper fed by the separation paper feeding unit, the separated paper feeding unit outputs 1 from the paper storage unit at a timing prior to a paper feeding command. A paper type information acquiring method in which a leading end of a sheet is fed by a predetermined amount, and the paper type detecting means detects the paper type of the paper to acquire paper type information. 23. The paper type information obtaining method according to claim 22, wherein at least when the power of the image forming apparatus is turned on, a paper type detection operation of the paper is performed to obtain the paper type information as a timing prior to the paper feed command. . 23. The paper type according to claim 22, wherein, as the timing prior to the paper feed instruction, when the paper is loaded into the paper storage unit, the paper type detection operation is performed to obtain the paper type information. Information acquisition method. The paper storage unit includes a paper cassette that can be pulled out and stored in the image forming apparatus main body, and each time the drawn paper cassette is stored in the image forming apparatus main body, the paper type of the paper is set. The paper type information obtaining method according to claim 24, wherein the paper type information is obtained by performing a detecting operation. As a timing prior to the paper feed command, after the paper is fed from the paper storage unit based on the preceding paper feed command, before the next paper feed command is issued, the paper is stored in the paper storage unit. The paper type information obtaining method according to claim 22, wherein the paper type information is obtained by performing a paper type detection operation. At least the paper stacked and held in a paper storage unit including a paper cassette that can be pulled out and stored in the image forming apparatus main body is separated and fed one by one by a separation feeding unit, and an image is formed on the fed paper. A sheet feeding control method used in an image forming method in which an image is formed by a forming unit,
Using a paper type detection unit that detects a paper type including at least the thickness of the paper fed by the separation paper feeding unit, the separated paper feeding unit outputs 1 from the paper storage unit at a timing prior to a paper feeding command. A paper type detecting paper feeding step of feeding a predetermined amount of the leading end of the paper sheets and providing the paper type detection means for detecting the paper type of the paper;
A pull-back step of pulling the paper fed by a predetermined amount from the paper feed cassette back into the corresponding paper feed cassette after detecting the paper type by the paper type detection means;
And a paper feed control method. An image used in an image forming method in which sheets stacked and held in a sheet storage unit are separated and fed one by one by a separating sheet feeding unit, and an image is formed on the fed sheet by an image forming unit by an electrophotographic method. A forming operation control method,
Using a paper type detection unit that detects a paper type including at least the thickness of the paper fed by the separation paper feeding unit, the separated paper feeding unit outputs 1 from the paper storage unit at a timing prior to a paper feeding command. A paper type information obtaining step of obtaining a paper type information by detecting a paper type of the paper by the paper type detection means by feeding a predetermined amount of a leading end of the paper sheets,
A fixing temperature setting step of variably setting a fixing temperature in accordance with the paper type information obtained in the paper type information obtaining step at a timing prior to the paper feeding instruction when a paper feeding instruction is received;
A sheet feeding and transporting step of feeding and transporting the sheet toward the image forming unit after variably setting the fixing temperature,
And an image forming operation control method. An image forming operation control method used in an image forming method in which sheets stacked and held in a sheet storage unit are separated and fed one by one by a separating sheet feeding unit, and an image is formed on the fed sheet by an image forming unit. And
Using a paper type detection unit that detects a paper type including at least the thickness of the paper fed by the separation paper feeding unit, the separated paper feeding unit outputs 1 from the paper storage unit at a timing prior to a paper feeding command. A paper type information obtaining step of obtaining a paper type information by detecting a paper type of the paper by the paper type detection means by feeding a predetermined amount of a leading end of the paper sheets,
A process speed setting step of variably setting a process speed of the image forming unit according to the paper type information acquired by the paper type information acquiring step at a timing prior to the paper supply instruction when a paper supply instruction is received;
A paper feed transporting step of feeding and transporting the paper toward the image forming unit after the process speed is variably set,
And an image forming operation control method. An image used in an image forming method in which sheets stacked and held in a sheet storage unit are separated and fed one by one by a separating sheet feeding unit, and an image is formed on the fed sheet by an image forming unit by an electrophotographic method. A forming operation control method,
Using a paper type detection unit that detects a paper type including at least the thickness of the paper fed by the separation paper feeding unit, the separated paper feeding unit outputs 1 from the paper storage unit at a timing prior to a paper feeding command. A paper type information obtaining step of obtaining a paper type information by detecting a paper type of the paper by the paper type detection means by feeding a predetermined amount of a leading end of the paper sheets,
An image forming condition setting step of variably setting an image forming condition of the image forming unit according to the sheet type information acquired in the sheet type information acquiring step at a timing prior to the sheet feeding instruction when a sheet feeding instruction is received; ,
A paper feeding step of feeding the paper toward the image forming unit after variably setting the image forming conditions,
And an image forming operation control method.

Images