JP2004094096A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance a printing efficiency by minimizing a fixation idling period of time in the case of performing image formation continuously by using a plurality of paper classifications. <P>SOLUTION: This image forming apparatus performs fixation by a fixation means having a fixation roller 140 to be heated to a plurality of fixation temperatures, a pressurization roller 141 to be energized by facing the fixation roller 140, a thermistor 145 which detects surface temperature of the fixation roller 140 and a fixation control part 144 which controls lighting of a heating heater 142. The apparatus is provided with a plurality of paper feeding units 101a to 101d which detectably store the plurality of different kinds of paper and feed them and a control part 150 which performs print by the same paper classification when print data with the same paper classification as that of recording paper by which the print is first performed exists and controls the paper feeding units 101a to 101d and the fixation means so that the next print is transited to the paper classification close to fixation temperature of the paper classification in the previous print when the print of the plurality of paper classification is continuously performed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus having a fixing device for fixing a toner image on recording paper, such as a laser printer or a digital copier, and more particularly, to an image forming apparatus that supports a paper type such as plain paper, tracing paper, OHP film, and cardboard. And an image forming apparatus selectively provided with a paper type print mode for performing fixing at an appropriate fixing temperature.
[0002]
[Prior art]
2. Description of the Related Art In an image forming apparatus such as a copying machine, a printer, and a facsimile apparatus using an electrophotographic system, an electrostatic latent image is formed by irradiating light corresponding to image data onto a charged photoreceptor. Is visualized with a developing toner. Further, in general, an image is formed by a process of transferring a visible image on a photoreceptor onto recording paper, fixing it by a fixing device, and discharging the paper. Usually, the fixing device is roughly divided into a fixing roller that is heated to a predetermined temperature by inserting a heater in the center of a hollow pipe made of aluminum, and a pressure roller that is urged at a predetermined pressure with respect to the fixing roller. Have. Further, the surface of the fixing roller is coated with a Teflon (R) material having excellent releasability, and a thermistor is provided in contact with the surface. The temperature of the roller surface is detected by the thermistor, and the temperature is controlled within a certain range according to the detected temperature.
[0003]
In order to fix the unfixed toner transferred onto the recording paper, it is necessary to adjust the temperature of the fixing roller, the nip pressure between both rollers, and the fixing speed. Note that varying the fixing speed requires a speed control mechanism and reduces the printing efficiency.
[0004]
In copiers and laser printers, plain paper (high-quality, medium-quality general paper of about 55K), tracing paper used for the 2nd original drawing, thick paper such as postcards (about 135K paper), OHP Paper types such as a film typified by a sheet are to be recorded. However, the fixing temperature is usually controlled to a certain fixed temperature. In terms of fixing quality (fixing rate), a normal paper is cleared of a predetermined fixing rate, and the fixing temperature is increased for a paper type requiring a high fixing temperature. Is set to a fixing rate slightly lower than that of plain paper.
[0005]
In an image forming apparatus using a fixing device, when printing with the above-described paper types mixedly, it takes a standby time from the change of the paper type to the start of printing (until the fixing temperature is reached). For this reason, for example, in an "image forming apparatus" disclosed in Japanese Patent Application Laid-Open No. 9-222823, the fixing temperature is changed or the paper passing speed (copying speed) is changed for each paper type. Is made selectable, and the time from the paper type change to the copy end time is shortened.
[0006]
[Patent Document 1]
JP-A-9-222823
[Problems to be solved by the invention]
However, in the conventional image forming apparatus as described above, when a plurality of paper types are targeted and image formation is continuously performed, if the fixing temperature is changed for each paper type, the fixing temperature is increased or decreased. In this case, it is necessary to perform a so-called fixing idling operation to bring the temperature of the recording paper closer to an appropriate target temperature, thereby causing a problem of lowering the printing processing efficiency.
[0008]
Also, when image formation is performed continuously for multiple paper types, if the printing speed is changed for each paper type, the speed will decrease due to the lower fixability of tracing paper and thick paper compared to plain paper. I have to pass through the paper. That is, when the printing speed is reduced, the processing efficiency is eventually reduced.
[0009]
SUMMARY OF THE INVENTION The present invention has been made in view of the above, and in the case of performing image formation continuously on a plurality of paper types, improving the print processing efficiency by minimizing the fixing idling time. The purpose is to let them.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, in the image forming apparatus according to claim 1, a fixing roller heated to a plurality of fixing temperatures by turning on an inserted fixing heater, and a fixing roller facing the fixing roller. A fixing roller having a pressure roller urged at a predetermined pressure, a fixing temperature detecting means for detecting a surface temperature of the fixing roller, and a fixing control means for controlling lighting of the fixing heater. In an image forming apparatus for fixing a toner image, when a plurality of different paper types are stored in a detectable manner and a plurality of paper feeding units for feeding the papers and a plurality of paper type printings are continuously performed, printing is performed first. If there is print data of the same paper type as that of the recording paper, the printing is performed using the same paper type, and the paper feed is performed so that the next printing is shifted to a paper type close to the fixing temperature of the paper type of the previous printing. Means and said anchoring hand And control means for controlling, in which with a.
[0011]
According to the present invention, for example, when printing is continuously performed on different paper types such as tracing paper, film, and plain paper, a paper type having a fixing temperature close to that of the first printed paper type is set as a next printing target. It is possible to reduce the fixing idling time when changing the paper type by selecting the recording paper, performing printing while controlling the fixing temperature, and sequentially shifting to a paper type with a small change in the fixing temperature.
[0012]
The image forming apparatus according to claim 2, further comprising a selection unit that selects a paper type print mode in which print processing is performed for each paper type, wherein the control unit selects the paper type print mode. If there is print data of the same paper type as the recording paper on which printing was first performed, printing is performed on the same paper type, and the next printing is shifted to a paper type close to the fixing temperature of the paper type of the previous printing The paper feeding unit and the fixing unit are controlled so as to cause the paper feeding unit and the fixing unit to operate.
[0013]
According to the present invention, in the first aspect, for example, a paper type print mode for performing printing on different paper types such as tracing paper, film, and plain paper is provided so as to be selectable. The paper type having a fixing temperature close to the paper type printed on the recording paper is selected as the recording paper to be printed next, the fixing temperature is controlled and printing is performed, and the paper type is sequentially shifted to a paper type having a small change in the fixing temperature. This makes it possible to reduce the idling time until the fixing temperature is raised to a predetermined temperature when the paper type is changed.
[0014]
Further, in the image forming apparatus according to claim 3, when the center value of the fixing temperature for plain paper is T1, the control unit shifts the fixing temperature by 20 ° C. with respect to the center value T1. Is controlled.
[0015]
According to the present invention, when the central value of the fixing temperature (T1) of plain paper is set to, for example, 180 ° C., the central values of the fixing temperature for other paper types are set to 160 ° C. and 200 ° C. By doing so, it is possible to ensure the fixability for almost all paper types.
[0016]
In the image forming apparatus according to a fourth aspect, the control unit executes printing from a paper type having a low fixing temperature when performing continuous printing of a predetermined number or more of paper types.
[0017]
According to the present invention, in the case where continuous printing of a fixed number or more of paper types is performed, printing is performed from a paper type having a low fixing temperature. Becomes the upper limit level, and the time until the next fixing temperature is reached is shortened.
[0018]
In the image forming apparatus according to the fifth aspect, the paper type print mode is configured to be selected by an operation display unit of the apparatus or (and) an external host computer.
[0019]
According to the present invention, in the second aspect, the paper type print mode is selected from the operation display means provided in the apparatus itself and / or the external host computer, so that the paper type continuous print mode can be selected. Thus, it is possible to improve the operability when printing each.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of an image forming apparatus according to the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to this embodiment. Although a laser printer is described as an example of the image forming apparatus, the image forming apparatus may be a digital copying machine or the like.
[0021]
According to the present invention, after image data to be printed is received by a printer controller from an external device (host device) such as a scanner or a personal computer, converted into print data, and subjected to predetermined image processing, the image data is temporarily stored in a memory. Paper type printing using an image forming apparatus, such as a laser printer or a digital copier, which stores the image data on a recording sheet and prints on a recording sheet, and further includes a plurality of paper feeders capable of storing a plurality of paper types and selecting a paper feed. A mode in which image data is sequentially output from the memory, and when printing on recording paper, the first priority is given to printing of the same paper type as the first output paper type, rather than the order in which the image data is stored, When the output of the paper type is completed, the paper type is sequentially shifted to a paper type having a small change in the fixing temperature so that a paper type close to the fixing temperature of the paper type which has been printing immediately before is output. It allows the fixing idling is intended to improve the printing efficiency by minimizing the. Hereinafter, a specific description will be given.
[0022]
FIG. 1 is a block diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus mainly includes a printer engine 100 for forming an image on recording paper in accordance with an electrophotographic process, and a control unit 150 as a control unit for controlling each functional unit including the printer engine 100 to perform an image forming process. And an operation display unit 160 having a function of displaying keys, apparatus statuses, and setting states for setting various modes and initial conditions, and an image to be printed transferred from an external device 190 such as a scanner or a personal computer. The printer includes a printer controller 170 that converts data into print data, and a memory 180 that stores print data sent from the printer controller 170.
[0023]
The printer engine 100 modulates a laser beam in accordance with the transferred print data and a paper feed unit of the paper feed units 101a to 101d that accommodate various types of recording paper (sheet bundle) and feed the paper one by one. A laser optical system 110 for exposing and irradiating the photosensitive drum, a photosensitive drum 115 on which an electrostatic latent image is formed, a charging charger 116 for charging the surface of the photosensitive drum 115, and a static charger formed on the surface of the photosensitive drum 115. A developing device 117 that develops the latent image into a visible image; a transfer separation charger 118 that transfers and separates the toner image formed on the photosensitive drum 115 onto recording paper; A cleaning device 119 for removing and collecting toner and the like, a registration roller 120 for adjusting the transfer timing of the recording paper, and fixing an unfixed toner image on the recording paper A fixing roller 140, a pressure roller 141 opposed to the fixing roller 140 and urged with a predetermined pressure, a heater 142 provided through the inside of the pipe-shaped fixing roller 140, and an AC An AC power supply 143 that supplies power, a fixing control unit 144 that controls the AC power supply 143 so that the fixing temperature becomes a predetermined value in accordance with an instruction from the control unit 150, and a non-image area of the fixing roller 140 that is contacted with a small pressure. And a thermistor 145 for detecting the surface temperature of the fixing roller 140. The temperature detected by the thermistor 145 is configured to be fed back to the control unit 150.
[0024]
In the image forming apparatus according to this embodiment, the paper feed units 101a to 101d include a first paper feed tray 102a, a second paper feed tray 102b, a third paper feed tray 102c, and a fourth paper feed tray 102d, respectively. Further, it has a pickup roller 103 for sending out the recording paper, a feed roller 104 for feeding the sent out recording paper toward the registration roller, and a separation roller 105 for separating the recording paper. The paper feed units 101a to 101d are configured to operate by pulling out the tray to the front. Each paper feed tray is provided with a paper type detection switch 106.
[0025]
FIG. 2 shows an example of the arrangement of the paper type detection switch 106. As shown in FIG. 2, the paper type detection switch 106 is composed of, for example, a push button type switch of P1 to P4 arranged on the tray portion so as to be pressed by the user. In this case, plain paper when P1 is switched on, tracing paper when P2 is switched on, film (OHP sheet) when P3 is switched on, and cardboard (OHP sheet) when P4 is switched on. Paper of about 135K such as a postcard) is loaded.
[0026]
The control unit 150 is configured by a microcomputer system. That is, although not shown, the image forming apparatus includes a CPU, a ROM, a RAM, an I / O port, an interface, and the like, and comprehensively controls the image forming apparatus using the RAM as a working memory according to a control program written in the ROM in advance. Things.
[0027]
The operation display unit 160 is composed of, for example, an LCD, and has an operation panel 161 for displaying the setting status of the apparatus and the current status, a ten-key group 162 for performing various inputs as necessary, various print modes, Particularly, in this example, a mode setting key 163 for setting / non-setting the paper type print mode is provided.
[0028]
Next, a series of operations of the image forming apparatus configured as described above will be described. When a print request is issued from the printer controller 170, the print data continuously recorded in the memory 180 is controlled to be sequentially output to the laser optical system 110 of the printer engine 100. At the same time, the timing and the like for various functional parts are controlled by the control unit 150.
[0029]
The laser optical system 110 modulates a semiconductor laser (not shown) in accordance with the print data, and irradiates a laser beam to the photosensitive drum 115 charged in advance via a polygon mirror (not shown), an fθ lens, a mirror, and the like. When this laser beam is applied, an electrostatic latent image corresponding to the print data is formed on the photosensitive drum 115. Further, the electrostatic latent image is developed by the developing device 117 as a toner image. The toner image is transferred onto the recording paper while being synchronized with the recording paper waiting at the registration roller 120. The recording paper onto which the toner image has been transferred is sent to a nip formed by a fixing roller 140 and a pressure roller 141, and is fixed by the action of heat and pressure. Then, a stack tray or a bin (both not shown) The paper is ejected on top. After the transfer, the residual toner and the like are removed from the surface of the photosensitive drum 115 by the cleaning device 119, and the surface of the photosensitive drum 115 returns to the initial state.
[0030]
In the image forming operation described above, since the present apparatus is equipped with four-stage paper feeders 101a to 101d, a recording paper of a desired paper type is set in an arbitrary tray in advance, and the paper corresponding to the paper type is set. The user presses the paper type detection switch 106 to make the control unit 150 recognize it. The control unit 150 sets the surface temperature (fixing temperature) of the fixing roller 140 to a predetermined temperature based on the detection temperature of the thermistor 145 so that the fixing temperature suitable for the paper type specified in the print request is obtained. The control is performed by turning on / off the heater 142.
[0031]
Next, an operation example of the paper type print mode according to the embodiment of the present invention will be described. FIG. 4 is a flowchart illustrating an operation procedure of the paper type print mode in the image forming apparatus according to the embodiment of the present invention. First, it is determined whether the paper type print mode is set (step S11). The setting of the paper type print mode is performed by pressing the mode setting key 163 of the operation display unit 160. When the paper type print mode is set, for example, as shown in FIG. 3, display information 201 indicating that the paper type print mode 201 is ON is displayed on the display panel 161. Further, paper type information 202 and the number of prints 203 corresponding to the trays of each row are displayed.
[0032]
If it is determined in step S11 that the paper type print mode has been set, the first print processing is executed (step S12). Subsequently, it is determined whether there is a print request for the same paper type as that currently being printed (step S13). If there is a print request for the same paper type as that currently being printed, the process returns to step S12.
[0033]
On the other hand, when it is determined that there is no print request of the same paper type as the paper type on which printing is currently performed, it is further determined whether or not print requests of a plurality of paper types are reserved (step S14). If it is determined that a print request for a plurality of paper types is reserved, the printing corresponding to the paper type closest to the fixing temperature of the currently printed paper type is executed (step S15). It returns to step S12. On the other hand, if it is determined in step S14 that print requests for a plurality of paper types are not reserved, printing is performed on the remaining print requests (step S16).
[0034]
For example, the fixing temperature for each paper type in the paper type print mode is set as follows. The control is performed at 165 to 190 ° C. for plain paper, 190 to 198 ° C. for tracing paper, and 160 to 168 ° C. for film.
[0035]
Alternatively, when the center value of the fixing temperature (T1) of plain paper is, for example, 180 ° C., the center value of the fixing temperature for other paper types is 160 ° C. (for film or thin paper), 200 ° C. (for tracing paper, cardboard, etc.). ), It is possible to secure the fixability to almost all paper types for image formation such as plain paper to special paper.
[0036]
In addition, when performing continuous printing of a certain number or more of paper types such as tracing paper, film, and plain paper, when printing is performed continuously by executing printing from a paper type (film, thin paper) with a low fixing temperature Since the fixing temperature reaches the upper limit level and the time required to reach the next fixing temperature (for example, plain paper) is shortened, the processing efficiency in continuous printing is improved.
[0037]
If the above-described paper-type print mode is not set, the heater 142 of the fixing roller 140 is controlled so that the optimum fixing temperature for plain paper is set as a default.
[0038]
【The invention's effect】
As described above, according to the image forming apparatus of the present invention (claim 1), for example, when printing is continuously performed on different paper types such as tracing paper, film, and plain paper, the first printed paper is used. By selecting a paper type having a fixing temperature close to the type as the recording paper to be printed next, performing printing while controlling the fixing temperature, and sequentially shifting to a paper type having a small change in the fixing temperature, Since the fixing idling time at the time of the change can be reduced, the print processing efficiency can be improved.
[0039]
According to the image forming apparatus of the present invention (claim 2), a paper type print mode for performing printing on different paper types such as tracing paper, film, and plain paper is provided so as to be selectable. When the paper type print mode is selected, a paper type having a fixing temperature close to that of the first printed paper type is selected as a recording sheet for the next printing, and the printing is performed by controlling the fixing temperature and sequentially. By shifting to a paper type with a small change in fixing temperature, it is possible to reduce the idling time until the fixing temperature is raised to a predetermined temperature due to the change in the paper type, thereby improving print processing efficiency. In addition to this, the paper type print mode can be selectively performed.
[0040]
According to the image forming apparatus of the present invention (claim 3), when the central value of the fixing temperature (T1) of plain paper is 180 ° C., for example, in claim 1 or 2, fixing to other paper types is performed. By setting the central value of the temperature to 160 ° C. and 200 ° C., printing with fixing property for almost all paper types such as plain paper to special paper is realized.
[0041]
Further, according to the image forming apparatus of the present invention (claim 4), in the case of performing continuous printing of a predetermined number or more of paper types according to claim 1 or 2, printing is performed from a paper type having a low fixing temperature. Accordingly, when printing is performed continuously, the fixing temperature reaches the upper limit level, and the time required to reach the next fixing temperature is shortened, so that the processing efficiency in continuous printing is improved.
[0042]
Further, according to the image forming apparatus of the present invention (claim 5), in claim 2, the paper type print mode is selected from operation display means provided in the apparatus itself and / or an external host computer. With such a configuration, it is possible to improve the operability of the user when he / she prints continuously for each paper type.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing an example of paper type detection and size detection of the paper feeding device according to the embodiment of the present invention.
FIG. 3 is an explanatory diagram showing a display example of a paper type print mode on the operation display unit according to the embodiment of the present invention;
FIG. 4 is a flowchart illustrating an operation procedure of a paper type print mode of the image forming apparatus according to the exemplary embodiment of the present invention.
[Explanation of symbols]
100 Printer Engines 101a to 101d Paper Feeder 106 Paper Type Detection Switch 110 Laser Optical System 140 Fixing Roller 141 Pressurizing Roller 142 Heater 144 Fixing Control Unit 150 Control Unit 160 Operation Display Unit 161 Operation Panel 163 Mode Setting Key 170 Printer Controller 180 memory 190 external device

Claims (5)

Detecting a fixing roller heated to a plurality of fixing temperatures by turning on an interposed fixing heater, a pressing roller urged against a predetermined pressure against the fixing roller, and a surface temperature of the fixing roller. An image forming apparatus for fixing a toner image on recording paper by a fixing unit having a fixing temperature detecting unit and a fixing control unit for controlling lighting of the fixing heater,
A plurality of paper feeding means for accommodating and feeding a plurality of different paper types respectively so as to be detectable,
When printing multiple paper types in succession, if there is print data of the same paper type as the recording paper that was printed first, printing is performed on the same paper type, and the next printing is performed Control means for controlling the paper feeding means and the fixing means so as to shift to a paper type close to the fixing temperature of the paper type;
An image forming apparatus comprising: Further, a selection unit for selecting a paper type print mode for performing a printing process for each paper type is provided,
When the paper type printing mode is selected, the control unit performs printing on the same paper type when there is print data of the same paper type as the recording paper type on which printing was first performed, and performs the next printing. 2. The image forming apparatus according to claim 1, wherein the paper feeding unit and the fixing unit are controlled to shift to a paper type that is close to a fixing temperature of the paper type of the previous printing. 3. 3. The control unit according to claim 1, wherein when the central value of the fixing temperature for plain paper is T1, the control unit controls the fixing temperature to be shifted by 20 ° C. from the central value T1 by 20 ° C. 3. Image forming apparatus. 3. The image forming apparatus according to claim 1, wherein the controller executes printing from a paper type having a low fixing temperature when performing continuous printing of a predetermined number or more of paper types. 4. 3. The image forming apparatus according to claim 2, wherein the paper type printing mode is configured to be selected by an operation display unit of the apparatus or / and an external host computer.

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