JP4706606B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine or a printer.

  In an image forming apparatus using an electrophotographic system such as a conventional copying machine or printer, for example, the user selects and sets the type of transfer material (thick paper, plain paper, thin paper) to be used on the operation display unit, and the information The transfer material conveyance speed or the fixing pressure of the fixing device is automatically set based on the above.

  However, if improper setting is performed due to a user's selection or setting mistake, there is a problem that image quality is deteriorated or a machine trouble is caused in some cases.

In order to eliminate such human errors, the paper type is automatically recognized, and the optimum print settings are automatically made based on it, so that the optimum printing can be performed without bothering the user. Has been proposed (Patent Document 1).
JP 2003-292170 A

  Although the technique disclosed in Patent Document 1 described above seems to be useful, a pressure sensor for discriminating the type of paper (plain paper, high-quality exclusive paper) protrudes on the paper conveyance path every time it is detected. Since it is an aspect to be made, it cannot be said that the machine trouble has been solved, and there seems to be a problem that the control becomes complicated.

  The present invention has been made in view of such a point. The purpose of the present invention is to provide a movable member that is displaced by contact of the transfer material being conveyed on the transfer path of the transfer material. An object of the present invention is to provide an image forming apparatus configured to change process conditions according to the amount.

  The object of the present invention can be achieved by the following constitutional requirements.

(1)
In an image forming apparatus having a configuration in which a toner image formed on an image carrier is transferred onto a transfer material and then fixed by a fixing device.
A movable member is provided at a direction change position for changing the transfer material conveyance direction, and the displacement of the movable member when the transfer material abuts is measured by the measurement means. Based on the measurement result, the process is performed by the control means. An image forming apparatus characterized by changing conditions.

(2)
In an image forming apparatus having a configuration in which a toner image formed on an image carrier is transferred onto a transfer material and then fixed by a fixing device.
A fixed guide member for changing the transfer material conveyance direction;
A movable member biased by a spring so as to occupy a position inside the guide surface of the fixed guide member, which is a direction change position for changing the transfer material conveyance direction;
Measuring means for measuring a displacement amount of the movable member displaced by the contact of the transfer material;
Control means for determining the type of transfer material from the measurement result of the measurement means, and taking out and setting the process conditions of the category corresponding to the determination;
An image forming apparatus comprising:

  According to the present invention, the movable member is displaced by the waist strength of the transfer material, and the process conditions are changed in accordance with the displacement amount, so that a high-quality image can be stably formed.

  Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments.

  FIG. 1 is a schematic diagram illustrating an example of the overall configuration of an image forming apparatus including a printer.

  In the figure, 10 is a photoconductor as an image carrier, 11 is a charging electrode as charging means, 12 is an exposure optical system as image writing means, 13 is a developing device including a developing sleeve 130 as developing means, and 14 is A cleaning device for cleaning the surface of the photoreceptor 10, 15 a cleaning blade, 17 a transfer electrode as a transfer means, 18 a separation electrode for separating the transfer material from the photoreceptor 10, and 19 after completion of the transfer process A separation claw for preventing the transfer material from being wound around the photosensitive member 10.

  The photoconductor 10, the charging electrode 11, the exposure optical system 12, the developing device 13, the transfer electrode 17, the separation electrode 18, the separation claw 19, the cleaning device 14, and the like constitute the image forming unit 1.

  The photoreceptor 10 is formed by forming a photosensitive layer such as a conductive layer, an a-Si layer, or an organic photosensitive layer (OPC) on the outer periphery of a cylindrical metal base formed of, for example, an aluminum material, and the conductive layer is grounded. It is rotated in the clockwise direction indicated by the arrow in the figure.

  20 is a transport belt having a plurality of holes, 21 is a driving roller, 22 is a driven roller, and 23 is a suction box. A plurality of holes are formed in a surface contacting the transport belt 20, and a duct (not shown) The transfer material P is connected to a suction fan or the like and sucks the transfer material P onto the traveling transport belt 20.

  The conveying means 2 is formed by the conveying belt 20, the driving roller 21, the driven roller 22, the suction box 23, and the like.

  Reference numeral 3 denotes a transfer material storage unit. Reference numeral 30 denotes a paper feed cassette, which is provided with IC tags relating to transfer material size selection and transfer material type (thick paper, plain paper, thin paper).

  31 is a delivery roller, 32 and 33 are a pair of transport rollers, 34 is a pair of timing rollers, 35 is a manual feed roller, 36 is a manual feed tray, 38 is a pre-registration roller, 39 is a guide rail for mounting the paper feed cassette 30 Thus, each paper feed cassette 30 can be pulled out from the apparatus main body along the guide rail.

  In addition, although the site | part enclosed with the broken line is a site | part which has arrange | positioned the movable member etc. concerning this invention, this structure is mentioned later.

  4 is a fixing device, 41 is a heat fixing roller, 42 is a pressure roller, 7 is an image reading unit (image reading device), 72 is a document pressing cover, 73 is a document size detection sensor (APS), and 75 is an operation panel. Buttons for operation functions such as transfer material size selection, image density designation, and numeric keypad are arranged in parallel.

  B1 is a control unit that not only controls the operation of the apparatus main body but also includes control means for executing various subroutines that operate in parallel with the main routine.

  Next, the image forming process will be briefly described with reference to FIG.

  First, when a transfer material size to be printed (or APS detection), image density, and the like are selected on the operation panel 75, a corresponding paper feed cassette 30 is selected via the main body control unit B1.

  When a drive motor (not shown) starts rotating due to the start of the image forming process, the photoconductor 10 rotates clockwise as indicated by an arrow.

  At the same time, application of a potential to the photoconductor 10 is started by the charging electrode 11.

  Image writing corresponding to the image data from the image reading device 7 is started through the exposure optical system 12 on the photosensitive member 10 after the potential is applied, and the electrostatic latent image corresponding to the original image is formed on the surface of the photosensitive member 10. An image is formed.

  The electrostatic latent image is reversely developed with the developer conveyed by the developing sleeve 130 of the developing device 13 to become a toner image (visible image).

  On the other hand, when the transfer material P is supplied from the transfer material storage unit 3 stored in the machine, the transfer material P is sent out by the feed roller 31 and is transported to the timing roller pair 34 through the pre-registration roller 38 and the transport roller pair 32. The

  As described above, the movable member according to the present invention is provided immediately after the paper feeding and at the place where the transfer material conveyance direction is changed, and the displacement amount due to the contact of the transfer material is measured. It is measured by means.

  Further, according to the amount of displacement, for example, at least one process condition of the fixing pressure of the fixing device 4, the transfer output (discharge current) of the transfer electrode 17 and the transfer speed of the transfer material is changed. The control for this is executed through the control means in the control unit B1.

  Returning, as described above, the transfer material P that has reached the timing roller pair 34 is sent out as the timing roller pair 34 that is driven to synchronize with the toner image on the photoconductor 10 is started. The sheet is fed to a transfer region between the transfer electrode 17 and the photoreceptor 10.

  Even in the case of manual sheet feeding, the transfer material P on the manual sheet feeding tray 36 is fed by the manual feed roller 35, conveyed to the timing roller pair 34 through the conveying roller pair 33, and synchronized with the toner image on the photoconductor 10. Is fed by driving the timing roller pair 34 and fed to a transfer region between the transfer electrode 17 and the photosensitive member 10.

  In the transfer region, the toner image is transferred onto the transfer material P by the transfer electrode 17 to which a voltage having a polarity opposite to that of the toner is applied.

  Thereafter, the photosensitive member 10 continues to rotate, is cleaned by the cleaning device 14, and is directed to the next image formation.

  On the other hand, the transfer material P on which the toner image is placed is subjected to a neutralization action by the AC voltage at the separation electrode 18, the adsorption force with the photoconductor 10 is weakened, and the curvature is separated from the photoconductor 10.

  When the transfer material P is affected by environmental humidity or the like and tends to be wound around the photoconductor 10, the transfer material P is separated by the action of the separation claw 19.

  The separated transfer material P is sent to the conveying means 2 and then subjected to fixing processing in the fixing device 4.

  In other words, the toner image is melted and fixed on the transfer material P by applying heat and pressure while being nipped and conveyed at the nip portion T between the heat fixing roller 41 and the pressure roller 42.

  The fixed transfer material P is discharged to a discharge tray 71 by a fixing discharge roller 43.

  Next, the configuration of the present invention will be described with reference to FIG.

  FIG. 2 is a schematic diagram showing an enlarged main configuration of a portion surrounded by a broken line in FIG.

  Reference numeral 300 is a fixed guide member provided at a direction changing position for changing the transfer direction of the transfer material P, 303 is a displaceable movable member located at the center of the fixed guide member 300, and these members are the transfer material. It extends in a direction perpendicular to the P conveying direction.

  Here, the direction change position refers to an initial position for changing the direction of the transfer material P (for example, an area including a change point where the transfer material starts to curve from a state where the transfer material is running on substantially the same plane, A region where the movable member is easily subjected to a pressing force by contact).

  The fixed guide member 300 has a predetermined curved surface or flat surface that enables the transfer material to change its direction, but may be configured as a part of a bent portion of a guide member that forms a flat guide surface indicated by a two-dot chain line.

  Further, the movable member 303 is biased by a spring (not shown) so as to occupy a position inside the guide surface of the fixed guide member 300 by an appropriate amount, and the leading end of the moving transfer material abuts. When they come into contact with each other, they move in parallel to the right and rearward in the drawing in accordance with the pressing force (contact force).

  An example for achieving translation of the movable member 303 is shown in FIG.

  In this example, guide rails (groove rails) are provided on the left and right sides of the movable member 303, and two rollers 307 are arranged in the groove, and the rollers 307 are supported by pins protruding from the fixed guide member 300. As a result, the movable member can be smoothly translated.

  Reference numeral 305 is a piezoelectric load cell that changes its output voltage through the movement of a pin 309 that is displaced according to the displacement of the movable member 303.

  The output voltage of the load cell 305 is converted into a digital signal by an amplifier, and the digital signal corresponds to which type of transfer material (thick paper, plain paper, thin paper) stored in the ROM of the control unit B1. Used to discriminate.

  Further, as a result of the discrimination, the process conditions of the category corresponding to the discrimination are extracted from the memory and set.

  As described above, the load cell 305 is a measuring unit that measures the displacement amount of the movable member 303, and the control unit B1 including the CPU and the memory determines the type of the transfer material and changes the process condition based on the determination result. You can say that.

  FIG. 4 shows a flow from contact of the transfer material to the movable member to determination of the type of transfer material.

  FIG. 5 is a diagram for explaining the type and classification of the transfer material and the control of the image forming apparatus.

  In FIG. 5, the displacement amount of the movable member 303 is divided into 10 steps from small to large.

  Thus, from detection accuracy or practical use, 1 to 3 are classified as thin paper, 4 to 7 as plain paper, and 8 to 10 as thick paper.

  When transfer of the transfer material is started and the displacement amount of the movable member is measured (detected), the type of the transfer material corresponding to the displacement amount is specified.

  For example, when the displacement amount is 9, it is determined that the paper is thick paper. At that time, when the condition setting on the apparatus side is set to plain paper, the setting is changed to a process condition corresponding to thick paper.

  Process conditions include fixing pressure of the fixing device, output of the transfer electrode, and transfer material conveyance speed, and one or a combination thereof is used as the change condition.

  For example, in the above case, if an image is formed under the condition of using plain paper even though the transfer material used is thick paper, a problem occurs in the image.

  However, the control according to the present invention, that is, the determination result is automatically reflected, so that the process condition is changed to the cardboard condition, so that it is possible to prevent the risk of jamming or image defects.

  The movable member 303 is made of ABS resin, but other resins such as PC resin, PC + ABS resin, POM resin, HIPS resin, PC + PS resin, etc. may be used.

  The size and mass of the movable member can be determined by various experiments.

  Further, regarding the displacement of the movable member, instead of the parallel movement, as shown in FIG. 6, it may be configured to rotate around the fulcrum.

  In addition, the angle α (see FIG. 6) formed by the moving direction of the transfer material and the surface of the movable member on which the transfer material abuts is preferably in the range of 100 to 170 degrees, particularly 110 to 140 degrees. Is practical and more preferable.

1 is a schematic diagram illustrating an example of an overall configuration of an image forming apparatus including a printer. It is the schematic which expands and shows the main structures of the site | part enclosed with the broken line in FIG. It is a figure which shows an example for achieving the parallel movement of a movable member. A flow from contact of the transfer material to the movable member to determination of the type of the transfer material is shown. It is a figure for demonstrating the kind and division of a transfer material, and control of an image forming apparatus. It is a figure which shows an example of the displacement of a movable member.

Explanation of symbols

300 Fixed Guide Member 303 Movable Member 305 Load Cell 307 Roller 309 Pin B1 Control Unit (Control Unit)

Claims (5)

In an image forming apparatus having a configuration in which a toner image formed on an image carrier is transferred onto a transfer material and then fixed by a fixing device.
A movable member is provided at a direction change position for changing the transfer material conveyance direction, and the displacement of the movable member when the transfer material abuts is measured by the measurement means. Based on the measurement result, the process is performed by the control means. An image forming apparatus characterized by changing conditions. In an image forming apparatus having a configuration in which a toner image formed on an image carrier is transferred onto a transfer material and then fixed by a fixing device.
A fixed guide member for changing the transfer material conveyance direction;
A movable member biased by a spring so as to occupy a position inside the guide surface of the fixed guide member, which is a direction change position for changing the transfer material conveyance direction;
Measuring means for measuring a displacement amount of the movable member displaced by the contact of the transfer material;
Control means for determining the type of transfer material from the measurement result of the measurement means, and taking out and setting the process conditions of the category corresponding to the determination;
An image forming apparatus comprising: The image forming apparatus according to claim 1, wherein the movable member is configured to rotate by contact of a transfer material. The image forming apparatus according to claim 1, wherein the movable member has a configuration in which the movable member moves in parallel when the transfer material comes into contact therewith. The image forming apparatus according to claim 1, wherein the process condition is at least one of a fixing pressure of a fixing device, an output of a transfer electrode, and a transfer material conveyance speed.

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